WorldWideScience

Sample records for exoelectron dosemeters

  1. Features of exoelectron emission in amorphous metallic alloys

    CERN Document Server

    Veksler, A S; Morozov, I L; Semenov, A L

    2001-01-01

    The peculiarities of the photothermostimulated exoelectron emission in amorphous metallic alloys of the Fe sub 6 sub 4 Co sub 2 sub 1 B sub 1 sub 5 composition are studied. It is established that the temperature dependences of the exoelectron emission spectrum adequately reflect the two-stage character of the amorphous alloy transition into the crystalline state. The exoelectron emission spectrum is sensitive to the variations in the modes of the studied sample thermal treatment. The thermal treatment of the amorphous metallic alloy leads to growth in the intensity of the exoelectrons yield. The highest growth in the intensify of the exoelectron emission was observed in the alloys at the initial stage of their crystallization

  2. Observations of exoelectron emission associated with heterogeneous catalysis

    Science.gov (United States)

    Hoenig, S. A.; Utter, M. G.

    1977-01-01

    It is suggested that the exoelectron emission from the catalyst may be used to monitor the rate of oxidation of CO and CH4 over palladium catalysts. Indirect heating of the catalyst and atmospheric pressure have no effect upon this monitoring system. Although the mechanism relating catalysis to exoelectron emission is not clear, it is considered possible that electron emission is triggered by the adsorption-desorption cycle.

  3. Performance tests on the NRPB thermoluminescent dosemeter

    CERN Document Server

    Shaw, K B

    1977-01-01

    Performance tests on the thermoluminescent dosemeter, designed at NRPB for use in the automated personal dosimetry system, are described. An ultra-thin lithium borate dosemeter has been developed for skin absorbed dose measurement. The X-ray, gamma-ray and beta-ray energy response of the dosemeter has been investigated and the angular response for the dosemeter has been examined. The annealing, read-out and stabilisation procedures for the dosemeter are described.

  4. Colour dosemeters for high level radiation dosimetry

    DEFF Research Database (Denmark)

    Schönbacher, H.; Coninckx, F.; Miller, A.

    1990-01-01

    Development work was undertaken in order to produce a visual dosemeter system for measurement of radiation levels around the present and future high energy particle accelerators. This dosemeter should exhibit radiation induced colours in the visible part of the spectrum leading to a visual dose...... radiation; and (2) a paint containing a base substance with a pigment. The paint dosemeter remained unaffected by irradiation up to 3 x 10(4) Gy while the film dosemeter showed a measurable colour change from 10(4) Gy to 5 x 10(5) Gy. Above 10(6) Gy the film dosemeter is destroyed by radiation. Samples...... of paint and film dosemeters were installed in the 450 GeV Super Proton Synchrotron (SPS) at CERN and irradiated during operation for more than two years. Within the useful range of the dosemeters, dose comparisons with other dosemeter types gave satisfactory results. Application in other fields...

  5. Optically stimulated exoelectron emission processes in quartz: comparison of experiment and theory

    DEFF Research Database (Denmark)

    Pagonis, V.; Ankjærgaard, Christina; Murray, A.S.

    2009-01-01

    Recent experiments have demonstrated that it is possible to measure optically stimulated exoelectron emission (OSE) signals simultaneously with optically stimulated luminescence (OSL) from quartz samples. These experiments provide valuable information on the charge movement in quartz grains. Two...... specific experiments measured the temperature dependence of the OSL and OSE signals on preheat and stimulation temperature. This paper provides a quantitative description of these experiments by using a previously published theoretical model for photostimulated exoelectron emission (PSEE). The experimental...... data yield a value of χ1.2 eV for the work function of quartz. The experimental temperature dependence of the OSE signals is interpreted on the basis of a photo-thermostimulated (PTSEE) process involving the main OSL trap at 320 °C; this process takes place with a thermal assistance energy estimated...

  6. Passive neutron dosemeter with activation detector

    Energy Technology Data Exchange (ETDEWEB)

    Valero L, C.; Banuelos F, A.; Guzman G, K. A.; Borja H, C. G.; Hernandez D, V. M.; Vega C, H. R., E-mail: fermineutron@yahoo.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2011-10-15

    A passive neutron dosemeter with {sup 197}Au activation detector has been developed. The area dosemeter was made as a 20.5 {phi} x 20.5 cm{sup 2} polyethylene moderator, with a polyethylene pug where a {sup 197}Au foil can be located either parallel or perpendicular to moderator axis. Using Monte Carlo methods, with the MCNP5 code. With the fluence response and the fluence-to-equivalent dose conversion coefficients from ICRP-74, responses to H*(10) were also calculated, these were compared against responses of commercially available neutron area monitors and dosemeters. (Author)

  7. The relative merits of discriminating and non-discriminating dosemeters

    DEFF Research Database (Denmark)

    Marshal, T. O.; Christensen, Palle; Julius, H. W.

    1986-01-01

    The need for discriminating and non-discriminating personal dosemeters in the field of radiological protection is examined. The ability of various types of dosemeter to meet these needs is also discussed. It is concluded that there is a need for discriminating dosemeters but in the majority...... of cases a simple two element non-discriminating dosemeter will suffice. In cases where the use of discriminating dosemeters is justified, thermoluminescence dosemeters can be designed to provided information on radiation type and energy, but if further information is required the photographic film...

  8. Charge recombination processes in minerals studied using optically stimulated luminescence and time-resolved exo-electrons

    DEFF Research Database (Denmark)

    Tsukamoto, Sumiko; Murray, Andrew; Ankjærgaard, Christina

    2010-01-01

    on the probability of (1) escape of electrons into the detector gas from the conduction band by overcoming the work function of the material and (2) thermalization of electrons in the conduction band, and subsequent re-trapping/recombination. Thus, we expect the exo-electron signal to reflect the instantaneous...

  9. Unbiased metal oxide semiconductor ionising radiation dosemeter

    Energy Technology Data Exchange (ETDEWEB)

    Kumurdjian, N.; Sarrabayrouse, G.J.

    1995-12-31

    To assess the application of MOS devices as low dose rate dosemeters, the sensitivity is the major factor although little studies have been performed on that subject. It is studied here, as well as thermal stability and linearity of the response curve. Other advantages are specified such as large measurable dose range, low cost, small size, possibility of integration. (D.L.). 21 refs.

  10. Operational experience of electronic active personal dosemeter and comparison with CaSo4:Dy TL dosemeter in Indian PHWR.

    Science.gov (United States)

    Singh, Vishwanath P; Managanvi, S S; Bihari, R R; Bhat, H R

    2013-01-01

    Direct reading dosemeter has been used for day-to-day radiation exposure control and management for last four decades in Indian nuclear power plants (NPPs). Recently new real time, alarm and pre-alarm on equivalent dose/dose rate, storage of dose/dose rate and maximum dose rate, user-friendly electronic active personal dosemeter (APD) has been implemented into practice for the first time at Kaiga Atomic Power Station-3&4,  of Indian NPPs. The dosemeter showed tolerance level (L) 0.1085±0.0450 compared with 0.1869±0.0729 (average±SD) for CaSO4:Dy, TL dosemeter, having narrow range trumpet curve, nil electromagnetic interference. Records of >29 000 for APD and TL dosemeter were analysed for comparasion of the measurement of the individual dose. APD followed general acceptance rule of ±25 % for dose >1 mSv. Monthly Station collective dose by TL dosemeters and APD for normal reactor operation as well as outage are found in good agreement. Operational experiences and statistical analysis support that an APD dosemeter is reasonably equivalent to CaSO4:Dy TL dosemeter. The accuracy, reproducibility and repeatability of the measurement of radiation for (137)Cs are comparable with CaSO4:Dy, TL dosemeter. Operational experience of APD during the normal operation as well as outage showed as one of the best ALARA tool for occupational dose monitoring, control, management and future outage planning.

  11. An international intercomparison of passive dosemeters, electronic dosemeters and dose rate meters used for environmental radiation measurements

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Thompson, I.M.G.

    1995-01-01

    To assist towards the harmonisation within the EC countries, the Eastern European countries and the USA, of the measurement of environmental dose rates from photon radiation an EC sponsored intercomparison of environmental dose rate meters, electronic dosemeters and TL dosemeters was performed...... Measurement Stations during the period 12 to 18 June 1994. The chief aims of the experiments were to allow the participants to check their home calibrations of their detectors and to intercompare the dosemeter responses of the individual environmental radiation measurement systems used in the USA, Eastern...

  12. Calibration of Far West Technology (FWT-60) radiachromic dye dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Mincher, B.J.; Zaidi, M.K.

    1992-08-01

    Radiachromic dye dosimetry was used to measure kilogray doses absorbed by various liquid samples during gamma-ray exposure in a spent nuclear fuel pool. The source of nuclear fuel was the Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory (INEL). Calibrations were performed using a {sup 60}Co source and were run on bare dosemeters, as well as on dosemeters which mocked to simulate the samples. These dosemeters were prepared as a dye-impregnated nylon film and are commercially available. When exposed to gamma-ray doses of 0.5 to 200 kGy, a color change occurs which has an optical density proportional to absorbed dose. The difference in the calibration curves demonstrated the importance of irradiation of dosemeters under conditions as close to the actual samples as possible. Since these dosemeters could not be immersed directly in the organic solutions of interest, they were sandwiched between layers of lucite and stainless steel. This simulated the conditions inside an irradiated sample and provides a practical method of measuring absorbed doses. The reproducibility of measurements using the radiachromic dye dosemeters is also shown. 10 refs.

  13. Calibration of Far West Technology (FWT-60) radiachromic dye dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Mincher, B.J.; Zaidi, M.K.

    1992-01-01

    Radiachromic dye dosimetry was used to measure kilogray doses absorbed by various liquid samples during gamma-ray exposure in a spent nuclear fuel pool. The source of nuclear fuel was the Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory (INEL). Calibrations were performed using a {sup 60}Co source and were run on bare dosemeters, as well as on dosemeters which mocked to simulate the samples. These dosemeters were prepared as a dye-impregnated nylon film and are commercially available. When exposed to gamma-ray doses of 0.5 to 200 kGy, a color change occurs which has an optical density proportional to absorbed dose. The difference in the calibration curves demonstrated the importance of irradiation of dosemeters under conditions as close to the actual samples as possible. Since these dosemeters could not be immersed directly in the organic solutions of interest, they were sandwiched between layers of lucite and stainless steel. This simulated the conditions inside an irradiated sample and provides a practical method of measuring absorbed doses. The reproducibility of measurements using the radiachromic dye dosemeters is also shown. 10 refs.

  14. Household and workplace chemicals as retrospective luminescence dosemeters

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov; Bøtter-Jensen, L.; Murray, A.S.

    2002-01-01

    In the development of techniques for the retrospective assessment of the close absorbed by communities living and working adjacent to the site of a nuclear accident, attention has concentrated on the use Of natural minerals such as quartz and feldspar as dosemeters. These minerals are widely foun...

  15. Radiological environmental monitoring with LiF-700-H dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Scarnichia, E.; Levanon, I.; Andres, P.; Miani, C.; Ramirez, S., E-mail: andresp@cab.cnea.gov.ar [Comision Nacional de Energia Atomica, Centro Atomico Bariloche, Grupo Proteccion Radiologica, Exequiel Bustillo 5AV 9500, R8402AGP San Carlos de Bariloche, Rio Negro (Argentina)

    2011-10-15

    Since 2008 a radiological environmental monitoring with LiF-700-H has been carried out as a result of increasing the Ra-6 research reactor core power. The information obtained is used to evaluate and to quantify analytically the air kerma rate, the fading and the associated uncertainty by developing software tools (deconvolution and uncertainty algorithms). LiF-700-H dosemeters were chosen because of their high sensitivity to low air kerma rates. They show a very good stability and a negligible fading for two-month working periods. The air kerma rate detection limit (based on the 3{sigma} criterion) during these working periods is about 0.4 n Gy/h. Air kerma rates of about 70 n Gy/h are measured with this detection limit. Following the Nist guidelines, an algorithm was developed in order to find the associated uncertainty. It considers several aspects, such as the source activity decay, distance source-dosemeter during the calibration procedure, irradiation time, calibration factor, dosemeter readout, dosemeter sensitivity, TLD reader stability and fading. The associated uncertainty is found to be about 25% for a 95% confidence interval (k = 2.025), which can be considered acceptable when taking into account the very low air kerma rates estimated. The LiF-700-H response to different energies and its relationship with climate changes over the calendar year are planned as future tasks. (Author)

  16. Graphite mixed magnesium borate TL dosemeters for beta ray dosimetry

    DEFF Research Database (Denmark)

    Prokic, M; Christensen, Poul

    1984-01-01

    Sintered MgB4O7:Dy dosemeters with graphite contents from 1 to 10% were investigated for application for personnel dosimetry. Data are given on dose response, dose threshold, reproducibility, beta energy response and fading. Furthermore, results from practical field experiments are presented...

  17. Aluminium nitrate ceramics: A potential UV dosemeter material

    DEFF Research Database (Denmark)

    Trinkler, L.; Bøtter-Jensen, L.; Berzina, B.

    2002-01-01

    The ceramic material AIN-Y2O3 is proposed as a potential ultraviolet radiation (UVR) dosemeter using optically stimulated luminescence (OSL) and thermally stimulated luminescence (TL). Experimental studies have shown that AIN ceramics exhibit attractive characteristics suitable for practical UV d...

  18. Evaluation of BICRON NE MCP DXT-RAD passive extremity dosemeter

    CERN Document Server

    Yuen, P S; Frketich, G; Rotunda, J

    1999-01-01

    Passive extremity dosemeters currently used in dosimetry communities worldwide have shortcomings. In general, an extremity dosemeter has too thick a detector element, and the dosemeter response is highly energy dependent for beta rays with energies ranging from 200 keV to 2 MeV. It often does not have dosemeter identification, causing problems in the chain of custody. It is often read manually, rendering reading/packing operations very labour intensive. As a result of collaboration between AECL and BICRON NE, a new extremity dosemeter, incorporating a highly sensitive LiF:Mg,Cu,P TLD and tentatively code named MCP DXT-RAD, was developed. It has been evaluated for radiological performance against an ISO draft standard for extremity dosemeters in twelve categories: homogeneity, detection threshold, beta ray energy response, beta angular response, photon energy response, photon angular response, reproducibility, stability under various climatic conditions, linearity, residue, self irradiation, and effect of ligh...

  19. Type testing of personal dosemeters for photon energy and angular response

    DEFF Research Database (Denmark)

    Julius, H.W.; Marshall, T.O.; Christensen, Poul

    1994-01-01

    Performance criteria for personal dosemeters have been recently proposed in the CEC document 'Technical Recommendations for Monitoring Individuals Occupationally Exposed to External Radiation' (EUR 5287, Revised). The current experiment was carried out to demonstrate that TLD-based dosimetry...... - but unknown! - influence on the dosemeters from the difference in backscatter between tissue-equivalent material and PMMA....

  20. A method for evaluating personal dosemeters in workplace with neutron fields.

    Science.gov (United States)

    de Freitas Nascimento, Luana; Cauwels, Vanessa; Vanhavere, Filip

    2012-04-01

    Passive detectors, as albedo or track-etch, still dominate the field of neutron personal dosimetry, mainly due to their low-cost, high-reliability and elevated throughput. However, the recent appearance in the market of electronic personal dosemeters for neutrons presents a new option for personal dosimetry. In addition to passive detectors, electronic personal dosemeters necessitate correction factors, concerning their energy and angular response dependencies. This paper reports on the results of a method to evaluate personal dosemeters for workplace where neutrons are present. The approach here uses few instruments and does not necessitate a large mathematical workload. Qualitative information on the neutron energy spectrum is acquired using a simple spectrometer (Nprobe), reference values for H*(10) are derived from measurements with ambient detectors (Studsvik, Berthold and Harwell) and angular information is measured using personal dosemeters (electronic and bubbles dosemeters) disposed in different orientations on a slab phantom.

  1. RESPONSE OF DOSEMETERS IN FIELDS GENERATED BY LASER-ACCELERATED PROTONS.

    Science.gov (United States)

    Olšovcová, V; Versaci, R; Ambrožová, I; Zelenka, Z; Kaufman, J; Margarone, D; Kim, I J; Jeong, T M

    2016-09-01

    In laser-driven acceleration, ultra-short and intense laser pulses are focussed on targets to generate beams of ionising radiation. One of the most important issues to be addressed is personal monitoring. While traditional dosemeters were designed primarily for measurements in continuous fields, dosemeters for laser laboratories must be capable of working in pulsed fields of pulse length below 1 ps, in a single-shot regime up to the repetition rate of 1 kHz. Responses of conventional dosemeters (films, polyallyldiglycol carbonate, electronic personal dosemeter) to proton bunches of up to 30 MeV energy produced by South Korean PW laser system at the Advanced Photonics Research Institute, Gwangju Institute of Science and Technology were studied, both by means of Monte Carlo simulations and experimentally. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Use of commercial alanine and TL dosemeters for dosimetry intercomparisons among Italian radiotherapy centres.

    Science.gov (United States)

    Onori, S; Bortolin, E; Calicchia, A; Carosi, A; De Angelis, C; Grande, S

    2006-01-01

    In the implementation of a large-scale dosimetry intercomparison one of the main constraints is the availability of large number of dosemeters of the highest quality. Therefore, ISS tested the possibility of using commercially available dosemeters, alanine pellets and thermoluminescence (TL) dosimetry chips, for transfer dosimetry within the Italian intercomparison programme. In this work the characterisation of commercial alanine and TL dosemeters along with the ISS dose assessment procedure used in the Italian intercomparison are reported. Results demonstrate the feasibility of the ISS approach to transfer dosimetry since it is possible to measure 10 Gy with a combined uncertainty of 1% (1sigma) and 1 Gy with a combined uncertainty of 1.7% (1sigma) with alanine and TL dosemeters, respectively.

  3. Sensitivity of a LR-115 based radon dosemeter

    Energy Technology Data Exchange (ETDEWEB)

    Bagnoli, F.; Bochicchio, F.; Bucci, S

    1999-06-01

    The first results of a study on the sensitivity of a LR-115 based radon dosemeter as a function of the absorber thickness are presented. The theoretical sensitivity was analytically calculated considering a constant detector response to alpha particles within a given energy range and up to a critical angle of incidence. The results are presented in two extreme situations: i) both radon and its decay products uniformly distributed in the chamber volume; ii) radon decay products uniformly deposited on the chamber walls. The agreement with the experimental curve shape appears better in the former case, suggesting that either the parameter values of the model could be different from the chosen values, or the model was too simplified.

  4. Sensitivity of a LR-115 based radon dosemeter

    CERN Document Server

    Bagnoli, F; Bucci, S

    1999-01-01

    The first results of a study on the sensitivity of a LR-115 based radon dosemeter as a function of the absorber thickness are presented. The theoretical sensitivity was analytically calculated considering a constant detector response to alpha particles within a given energy range and up to a critical angle of incidence. The results are presented in two extreme situations: i) both radon and its decay products uniformly distributed in the chamber volume; ii) radon decay products uniformly deposited on the chamber walls. The agreement with the experimental curve shape appears better in the former case, suggesting that either the parameter values of the model could be different from the chosen values, or the model was too simplified.

  5. 1983 ORNL intercomparison of personnel neutron and gamma dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Swaja, R.E.; Sims, C.S.; Greene, R.T.

    1985-01-01

    The Ninth Personnel Dosimetry Intercomparison Study was conducted during April 19-21, 1983, at the Oak Ridge National Laboratory. Dosemeters from 33 participating agencies were mounted on water-filled polyethylene elliptical phantoms and exposed to a range of low-level dose equivalents (0.02-0.45 mSv gamma and 0.49-11.14 mSv neutron) which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor served as the radiation source for six separate exposures which used four different shield conditions: unshielded and shielded with steel, steel/concrete, and concrete. Results of the neutron measurements indicate that it is not unusual for dose equivalent estimates made under the same conditions by different agencies to differ by more than a factor of 2. Albedo systems, which were the most popular neutron monitors in this study, provided the most accurate results with CR-39 recoil track being least accurate. Track and film neutron systems exhibited problems providing measurable indication of neutron exposure at dose equivalents of about 0.50 mSv. Gamma measurements showed that TLD and film systems generally overestimated dose equivalents in the mixed radiation fields with film exhibiting significant problems providing measurable indication of gamma exposure at dose equivalents lower than about 0.15 mSv. Under the conditions of this study in which exposures were carefully controlled and participants had information concerning exposure conditions and incident spectra prior to dosemeter analysis, only slightly more than half of all neutron and gamma dose equivalent estimates met regulatory accuracy standards relative to reference values. These results indicate that continued improvement of mixed-field personnel dosimetry is required by many participating organizations. 15 references, 30 tables.

  6. HOW DO HOSPITAL STERILISATION PROCEDURES AFFECT THE RESPONSE OF PERSONAL EXTREMITY RINGS AND OF EYE LENS TL DOSEMETERS?

    Science.gov (United States)

    Kopeć, Renata; Bubak, Anna; Budzanowski, Maciej; Sas-Bieniarz, Anna; Szumska, Agnieszka

    2016-09-01

    Stringent standards of hygiene must be applied in medical institutions, especially at operating blocks or during interventional radiology procedures. Medical equipment, including personal dosemeters that have to be worn by medical staff during such procedures, needs therefore to be sterilised. In this study, the effect of various sterilisation procedures has been tested on the dose response of extremity rings and of eye lens dosemeters in which thermoluminescent (TL) detectors (of types MTS-N and MCP-N, respectively) are used. The effects of medical sterilisation procedures were studied: by chemicals, by steam or by ultraviolet (UV), on the dose assessment by extremity rings and by eye lens dosemeters. Since it often happens that a dosemeter is accidentally machine-washed together with protective clothing, the effect of laundering on dose assessment by these dosemeters was also tested. The sterilisation by chemicals is mostly safe for TL detectors assuming that the dosemeters are waterproofed. Following sterilisation by water vapour, the response of these dosemeters diminished by some 30 %, irrespectively of the period of sterilisation; therefore, this method is not recommended. UV sterilisation can be applied to EYE-D™ eye lens dosemeters if their encapsulation is in black. The accidental dosemeter laundry in a washing machine has no impact on measured dose. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. The first operational dosemeter for neutrons which complies with IEC standard 1323.

    Science.gov (United States)

    Lahaye, T; Cutarella, D; Ménard, S; Bolognese-Milsztajn, T

    2001-01-01

    Individual neutron dosimetry represents one of the current difficulties in the field of radiological protection of workers. Since March 1999, the regulatory requirements in France for active (i.e. operational) dosimetry have been those of ICRP Publication 60, applicable from May 2000, necessitating the introduction of a new generation of neutron dosemeters. Over the last few years, the Institute for Nuclear Safety and Protection has been studying an individual electronic dosemeter for neutrons based on a semiconducting detector, capable of meeting the specifications laid down by a neutron dosimetry work group, including members from all the main players in the French nuclear industry. In 1998, the IPSN began transferring technology to the Saphymo company which, by the end of 2001, will be marketing Saphydose-n, the first individual dosemeter for neutrons which complies with IEC Standard 1323. This dosemeter is of compact design and can assess the individual dose equivalent Hp(10) in mixed neutron and gamma radiation fields. It wil be usable in any nuclear facility without prior knowledge of the average neutron spectrum or of the neutron-gamma ratio. It will be possible to connect the Saphydose-n dosemeter to any of the existing gamma deserter terminals to read the dose data and recharge the batteries.

  8. Wide energy range personnel neutron dosemeter and its dose evaluation system

    Energy Technology Data Exchange (ETDEWEB)

    Eisen, Y.; Eliau, A.; Faermann, S.; Karpinovitch, Z.; Ovadia, E.; Rosman, M.; Schlesinger, T.; Shamai, Y.; Tal, A. (Israel Atomic Energy Commission, Yavne. Soreq Nuclear Research Center)

    1982-01-01

    A system composed of a Rem response personnel neutron dosemeter for monitoring dose equivalents in the energy range 1 eV to 14 MeV, an electrochemical etching system for revealing damage sites in solid state track etch detectors, a reader for magnifying the etched pits and a microprocessor for evaluating the dose equivalents and their uncertainties are described. The performance and directional dependence of the dosemeter when exposed to monoenergetic and polyenergetic neutron fields in the epithermal and fast energy regions are discussed. Saturation effects in polycarbonate foils are presented and a comparison is made between the response of polycarbonate and CR-39 foils, used as passive detectors in the dosemeter.

  9. Independent evaluation of optically stimulated luminescence (OSL) 'dot' dosemeters for environmental monitoring.

    Science.gov (United States)

    Timilsina, Bindu; Gesell, Thomas F

    2011-01-01

    Optically stimulated luminescence (OSL) 'dot' dosemeters (manufactured by Landauer®) are reported to have a high degree of environmental stability, high level of sensitivity and provide wide range of dose measuring capabilities from 0.05 mGy to 100 Gy. The optical read out method is fast and relatively simple and permits repeated read out, but few studies have been performed about its application in monitoring radiation in the environment. This study was initiated to independently test the performance of OSL dot dosemeters for the application of measuring doses of radiation in the outdoor environment. Testing was performed in the laboratory to evaluate reproducibility and stability and in the field to evaluate accuracy relative to calibrated high-pressure ionisation chambers. The results showed that OSL dot dosemeters had good reproducibility and stability in both laboratory and field tests and met the performance requirements of standards of the American National Standards Institute.

  10. Development of personal neutron dosemeters at the PTB and first measurements in the space station MIR

    CERN Document Server

    Luszik-Bhadra, M; Schuhmacher, H

    2001-01-01

    A passive neutron dosemeter with thermoluminescence and etched-track detectors was used in the space station MIR in 1995 and 1997 and during some shuttle flights to MIR. High neutron doses of about 200 mu Sv d/sup -1/ were measured with track detectors, while the contribution of protons to the track density was estimated to be small. An active personal dosemeter based on silicon diodes providing a direct readout, improved sensitivity and spectrometric properties is proposed for additional monitoring. Firstly, measurements with a prototype were performed in the stray radiation fields of the CERN-EU Reference Radiation Facility. When mounted on a phantom at different positions, both the passive and the active dosemeter provide the directional distribution of neutrons via an unfolding procedure. This can be helpful for a better understanding of the complex radiation field in space and for comparisons with calculations. (21 refs).

  11. Eurados trial performance test for personal dosemeters for external beta radiation

    DEFF Research Database (Denmark)

    Christensen, P.; Bordy, J.M.; Ambrosi, P.

    2001-01-01

    On the initiative of the European Dosimetry Group (EURADOS) action group 'Harmonisation and Dosimetric Quality Assurance in Individual Monitoring for External Radiation' a trial performance test for whole-body and extremity personal dosemeters broadly representative of those in use in the EU...... was accomplished, This paper deals with the part of the performance test concerned with exposure to beta radiation. Fifteen dosimetric services participated with whole-body dosemeters intended to measure beta doses (H-p(0.07)) of which 13 used thermoluminescent (TL) detectors and two used photographic films. Eight...... services participated with extremity dosemeters which all used TL detectors. A description is given of the irradiation set-up, the characteristics of the irradiation fields, the calibration quantity applied and the performance criteria used for the evaluation of the results. The paper discusses in detail...

  12. Determination of Energy and Angular Response of an Albedo Neutron Personal Dosemeter

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Bernal, E.D.; Molina Perez, D.; Cornejo Diaz, N.; Carrazana Gonzalez, J. [La Habana (Cuba); Simoes da Fonseca, E. [Rio De Janeiro (Brazil)

    1999-07-01

    The result of the determination of energy and angular response for the albedo neutron personal dosemeter used by CPHR, is described. The dosemeters consist of two pairs of LiF detectors ({sup 6}LiF+{sup 7}LiF) separated by a piece of boron-loaded plastic. For the study, the dosemeters were irradiated in three mixed neutron-gamma fields (thermal neutrons, moderated {sup 241}Am-Be and {sup 241}Am-Be) and at two incidence angles of radiation (0 deg. and 60 deg. ). The variation of the sensibility at different neutron spectra and incidence angles of radiation was determined. The methodology of dose evaluation, applying the obtained coefficients, was established. (author)

  13. Some Characteristics of the TL Personal Dosemeter used by CPHR Individual Monitoring Service

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Bernal, E.; Molina-Perez, D. [La Habana (Cuba)

    1999-07-01

    In order to evaluate the performance characteristics of TL personal dosemeters used by the CPHR individual monitoring service, different performance tests were carried out. Some of the tests were those recommended by the International Electrotechnical Commission. The dosemeter consists of LiF:Mg,Ti (model JR1152C) detectors kept in a plastic holder. Important dosimetric characteristics evaluated were batch homogeneity, reproducibility, detection threshold, energy and angular dependence and fading. The result of the tests showed good performance characteristics of the detectors. (author)

  14. COMPARISON OF THE NEUTRON ENERGY RESPONSE OF TWO DIFFERENT TLD ALBEDO DOSEMETERS.

    Science.gov (United States)

    Freitas, B M; Silva, A X da; Pereira, W W; Mauricio, C L P

    2017-11-21

    Albedo dosemeters remain the most used dosemeters in neutron individual monitoring. In Brazil, most of the neutron occupational fields are from radionuclide sources, often without any moderation, where albedo dosemeters have poor energy response. The purpose of this work is to compare the HP(10) energy response of the IRD and ALNOR TLD albedo dosemeter systems, calculated by their modelling with Monte Carlo code MCNPX. Their energy responses are similar, as expected, but the IRD system is about five times more sensitive than the ALNOR one. IRD albedo system can measure the Brazilian monthly recording level of 0.2 mSv, even for bare 252Cf and 241Am-Be neutron fields. On the other hand, the ALNOR system can measure values higher than 0.2 mSv only after huge moderation of theses sources. These results show that IRD TLD albedo is more suitable than the ALNOR one to measure low doses at occupational fields from radionuclide sources. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. FIELD CALIBRATION OF A TLD ALBEDO DOSEMETER IN THE HIGH-ENERGY NEUTRON FIELD OF CERF.

    Science.gov (United States)

    Haninger, T; Kleinau, P; Haninger, S

    2017-04-28

    The new albedo dosemeter-type AWST-TL-GD 04 has been calibrated in the CERF neutron field (Cern-EU high-energy Reference Field). This type of albedo dosemeter is based on thermoluminescent detectors (TLDs) and used by the individual monitoring service of the Helmholtz Zentrum München (AWST) since 2015 for monitoring persons, who are exposed occupationally against photon and neutron radiation. The motivation for this experiment was to gain a field specific neutron correction factor Nn for workplaces at high-energy particle accelerators. Nn is a dimensionless factor relative to a basic detector calibration with 137Cs and is used to calculate the personal neutron dose in terms of Hp(10) from the neutron albedo signal. The results show that the sensitivity of the albedo dosemeter for this specific neutron field is not significantly lower as for fast neutrons of a radionuclide source like 252Cf. The neutron correction factor varies between 0.73 and 1.16 with a midrange value of 0.94. The albedo dosemeter is therefore appropriate to monitor persons, which are exposed at high-energy particle accelerators. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Fourth intercomparison of personal dosemeters used in US Department of Energy accelerator facilities

    CERN Document Server

    Stewart, R D; Otto, T; Loesch, R M

    2000-01-01

    Personal neutron dosemeters from seven US Department of Energy (DOE) laboratories were mailed to the European Laboratory for Particle Physics (CERN) and irradiated using the well-characterised CERN reference radiation facility (CERF). Neutron dose equivalents determined using the DOE personal dosemeters have been compared to the reference dose equivalent as determined using a tissue-equivalent proportional counter (TEPC). In the 0.5 to 5 mSv dose equivalent range, the comparison of results suggests that the neutron personal dosemeters in use at DOE facilities are capable of estimating dose equivalents for high energy neutrons to within a factor of at least 2 or 3. If a field-specific calibration factor is used to correct the dose equivalent responses, the agreement with the reference dose equivalent for these dosemeters can be improved to better than about 25 to 65at is decoupled from the core in /sup 183,185/Au, becomes the 3/2[532] state (h9/2 parentage) strongly coupled in the doubly-odd /sup 184/Au nucleu...

  17. Testing the direct ion storage dosemeter for personal dosimetry in a nuclear research centre and a hospital.

    Science.gov (United States)

    Vanhavere, F; Covens, P

    2010-03-01

    The direct ion storage (DIS) dosemeter can have some clear advantages in personal dosimetry. Before introducing the DIS into practice in the dosimetry service, a series of tests was performed on the linearity, angular and energy dependence, temperature influences and hard resets. After that, for several months, the DIS dosemeters were worn in parallel with the legal dosemeters (thermoluminescent badge) in a nuclear research centre and in several departments of a university hospital. The conclusions are that the DIS has good characteristics to be used as legal personal dosemeter, and that the comparison with the TLD badge is good. Only in interventional radiology and cardiology fields the DIS gives significant lower values than the TLD badge.

  18. Automatic exploitation system for photographic dosemeters; Systeme d`exploitation automatique des dosimetres photographiques

    Energy Technology Data Exchange (ETDEWEB)

    Magri, Y.; Devillard, D.; Godefroit, J.L.; Barillet, C.

    1997-01-01

    The Laboratory of Dosimetry Exploitation (LED) has realized an equipment allowing to exploit automatically photographic film dosemeters. This system uses an identification of the films by code-bars and gives the doses measurement with a completely automatic reader. The principle consists in putting in ribbon the emulsions to be exploited and to develop them in a circulation machine. The measurement of the blackening film is realized on a reading plate having fourteen points of reading, in which are circulating the emulsions in ribbon. The exploitation is made with the usual dose calculation method, with special computers codes. A comparison on 2000 dosemeters has shown that the results are the same in manual and automatical methods. This system has been operating since July 1995 by the LED. (N.C.).

  19. Further studies on sensitivity of a LR-115 based radon dosemeter

    Energy Technology Data Exchange (ETDEWEB)

    Bagnoli, F.; Bochicchio, F. E-mail: bochicchio@iss.infn.it; Bucci, S.; Marocco, D

    2001-06-01

    A radon dosemeter widely used in Italy and other countries has a cylindrically shaped diffusion cell and contains two LR-115 detectors covered by a thin film of absorber as an energy degrader. The sensitivity of this dosemeter was first studied by means of a simplified model for track formation in LR-115, based on three independent parameters (E{sub min}, E{sub max} and the critical angle {theta}{sub c}). In this work the model, which is based on analytic and standard numerical methods, has been modified to take into account the actual functional dependence of LR-115 response on alpha particle energy and incidence angle. The new computed sensitivity has been compared with a new set of experimental data obtained with absorber thickness ranging from 6 to 53 {mu}m.

  20. Evaluating the uncertainty in measurement of occupational exposure with personal dosemeters.

    Science.gov (United States)

    van Dijk, J W E

    2007-01-01

    In the 1990 Recommendations of the ICRP it is stated that an uncertainty in a dose measured with a personal dosemeter under workplace conditions of a factor 1.5 in either direction 'will not be unusual'. In many documents similar to the EU Technical recommendations, the IAEA Safety Guides and papers in scientific journals, this statement is understood to be a basis for developing type-test criteria and criteria for the approval of dosimetric systems. The methods for evaluating the standard uncertainty as proposed in the above mentioned documents and in national and international standards use an approach that is based on the Law of Propagation of Uncertainties (LPU). This approach needs a number of assumptions, the validity of which cannot easily be verified for personal dosemeters. The current paper presents a numerical method based on Monte Carlo simulation for the calculation phase of the evaluation of uncertainties. The results of applying the method on the type-test data of the NRG TL-dosemeter indicate that the combined standard uncertainty estimated using the LPU approach might well not be realistic. The numerical method is simple and can be precisely formulated, making it suitable for being part of approval or accreditation procedures.

  1. Validation of a MOSFET dosemeter system for determining the absorbed and effective radiation doses in diagnostic radiology.

    Science.gov (United States)

    Manninen, A-L; Kotiaho, A; Nikkinen, J; Nieminen, M T

    2015-04-01

    This study aimed to validate a MOSFET dosemeter system for determining absorbed and effective doses (EDs) in the dose and energy range used in diagnostic radiology. Energy dependence, dose linearity and repeatability of the dosemeter were examined. The absorbed doses (ADs) were compared at anterior-posterior projection and the EDs were determined at posterior-anterior, anterior-posterior and lateral projections of thoracic imaging using an anthropomorphic phantom. The radiation exposures were made using digital radiography systems. This study revealed that the MOSFET system with high sensitivity bias supply set-up is sufficiently accurate for AD and ED determination. The dosemeter is recommended to be calibrated for energies 80 kVp. The entrance skin dose level should be at least 5 mGy to minimise the deviation of the individual dosemeter dose. For ED determination, dosemeters should be implanted perpendicular to the surface of the phantom to prevent the angular dependence error. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Effective dose assessment in the maxillofacial region using thermoluminescent (TLD) and metal oxide semiconductor field-effect transistor (MOSFET) dosemeters: a comparative study

    NARCIS (Netherlands)

    Koivisto, J.; Schulze, D.; Wolff, J.; Rottke, D.

    2014-01-01

    Objectives: The objective of this study was to compare the performance of metal oxide semiconductor field-effect transistor (MOSFET) technology dosemeters with thermoluminescent dosemeters (TLDs) (TLD 100; Thermo Fisher Scientific, Waltham, MA) in the maxillofacial area. Methods: Organ and effective

  3. EXPERIMENTAL STUDY OF INDIVIDUAL THERMOLUMINESCENT DOSEMETERS PERFORMANCES FOR MEASURING THE DOSE EQUIVALENTS IN SKIN AND EYE LENS

    Directory of Open Access Journals (Sweden)

    E. N. Sheleenkova

    2014-01-01

    Full Text Available The article gives a comparative analysis of existing and newly developed thermoluminescent detectors DTG-4, TTLD-580, TLD-1011(TM and DTVS-01 and dosemeters MKD-A and MKD-B for the purposes of individual dosimetric control of skin and eye lens exposure to radiation. The dependence of sensitivity of different thermoluminescent dosemeters, designed for dose equivalents measurements in skin and eye lens on the type (photons and ȕ-particles and energy of radiation was determined experimentally. There are conclusions about the limits of applicability of existing detectors and dosemeters under different radiation exposure conditions. The article evaluates the possibility of different dosimeter use for specific radiation exposure conditions.

  4. Validation of response simulation methodology of Albedo dosemeter; Validacao da metodologia de simulacao de resposta de dosimetro de Albedo

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, B.M.; Silva, A.X. da, E-mail: bfreitas@nuclear.ufrj.br [Coordenacao do Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Mauricio, C.L.P. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2016-07-01

    The Instituto de Radioprotecao e Dosimetria developed and runs a neutron TLD albedo individual monitoring service. To optimize the dose calculation algorithm and to infer new calibration factors, the response of this dosemeter was simulated. In order to validate this employed methodology, it was applied in the simulation of the problem of the QUADOS (Quality Assurance of Computational Tools for Dosimetry) intercomparison, aimed to evaluate dosimetric problems, one being to calculate the response of a generic albedo dosemeter. The obtained results were compared with those of other modeling and the reference one, with good agreements. (author)

  5. Optical fibre dosemeter systems for clinical applications based on radioluminescence and optically stimulated luminescence from Al2O3:C

    DEFF Research Database (Denmark)

    Marckmann, C.J.; Andersen, C.E.; Aznar, M.C.

    2006-01-01

    Optical fibre dosemeter systems based on radioluminescence and optically stimulated luminescence (OSL) from carbon-doped aluminium oxide (Al2O3:C) crystals were developed for in vivo real-time dose rate and absorbed dose measurements in radiotherapy and mammography. A technique was also developed...... for making ultra-small dosemeter probes that can easily be placed inside patients in radiation treatment. These probes have shown excellent properties in both head and neck intensity-modulated radiation therapy treatment and in mammography. The dose-response of the OSL signal for the new optical fibre...

  6. INFLUENCE OF DIFFERENT TYPES OF PHANTOMS ON THE CALIBRATION OF DOSEMETERS FOR EYE LENS DOSIMETRY.

    Science.gov (United States)

    Yoshitomi, H; Kowatari, M

    2016-09-01

    Both a cylinder and a slab phantom have been recommended to be used as calibration phantoms for eye lens dosimetry in the International Atomic Energy Agency TECDOC. This study describes investigations on the influence of the type of phantom on the calibration of dosemeters. In order to fulfil the purpose, backscatter radiation from practically used water-filled phantoms was evaluated by calculations and experiments. For photons, the calculations showed that the cylinder phantom had 10 % lower backscattered effect at maximum than a slab phantom, and simulated well the backscattered effect of the human head or neck to within ±10 %. The irradiation results of non-filtered optically stimulated luminescence and radio-photoluminescence glass dosemeters indicated that the differences of the calibration factors between the two types of phantoms were up to 20 and 10 %, respectively, reflecting the response to backscattered photons. For electrons, no difference was found between the two types of phantoms. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Development of advanced-type multi-functional electronic personal dosemeter.

    Science.gov (United States)

    Nunomiya, T; Abe, S; Aoyama, K; Nakamura, T

    2007-01-01

    An advanced-type small, light, multi-functional electronic personal dosemeter has been developed using silicon semiconductor radiation detectors for dose management of workers at nuclear power plants and accelerator facilities. This dosemeter is 62 x 82 x 27 mm(3) in size and approximately 130 g in weight, which is capable of measuring personal gamma ray and neutron dose equivalents, Hp(10), simultaneously. The neutron dose equivalent can be obtained using two types of silicon semiconductors: a slow-neutron sensor (1 MeV). The slow neutron sensor is a 10 x 10 mm(2) p-type silicon on which a natural boron layer is deposited around an aluminium electrode. The fast neutron sensor is also a 10 x 10 mm(2) p-type silicon crystal on which an amorphous silicon hydride is deposited. The neutron energy response corresponding to the fluence-to-dose-equivalent conversion coefficient given by ICRP Publication 74 has been evaluated using a monoenergetic neutron source from 250 keV to 15 MeV at the Fast Neutron Laboratory of Tohoku University. As the result, the Hp(10) response to neutrons in the energy range of 250 keV and 4.4 MeV within +/-50% difference has been obtained.

  8. Spectral correction factors for conventional neutron dosemeters used in high-energy neutron environments.

    Science.gov (United States)

    Lee, K W; Sheu, R J

    2015-04-01

    High-energy neutrons (>10 MeV) contribute substantially to the dose fraction but result in only a small or negligible response in most conventional moderated-type neutron detectors. Neutron dosemeters used for radiation protection purpose are commonly calibrated with (252)Cf neutron sources and are used in various workplace. A workplace-specific correction factor is suggested. In this study, the effect of the neutron spectrum on the accuracy of dose measurements was investigated. A set of neutron spectra representing various neutron environments was selected to study the dose responses of a series of Bonner spheres, including standard and extended-range spheres. By comparing (252)Cf-calibrated dose responses with reference values based on fluence-to-dose conversion coefficients, this paper presents recommendations for neutron field characterisation and appropriate correction factors for responses of conventional neutron dosemeters used in environments with high-energy neutrons. The correction depends on the estimated percentage of high-energy neutrons in the spectrum or the ratio between the measured responses of two Bonner spheres (the 4P6_8 extended-range sphere versus the 6″ standard sphere). © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Viability of the Fricke dosemeter doped with methylene blue; Viabilidade do dosimetro Fricke dopado com azul de metileno

    Energy Technology Data Exchange (ETDEWEB)

    Souza, V.L.B.; Santos, C.D.A.; Rodrigues, K.R.G.; Cunha, M.S.; Figueiredo, M.D.C.; Melo, R.T. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2009-07-01

    This work aims to find the possible utilization of the Fricke dosemeter doped with methylene blue (FMB) for the dosimetry of photodynamic therapy. The FMB was irradiated wit X rays and light emitted diodes demonstrating positive answers to the stimulus, being probably to be used for dosimetric objectives

  10. In-vivo dosimetry in radiotherapy: a comparison of the response of semiconductor and thermoluminescence (TLD700) dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Vynckier, S. [Universite Catholique de Louvain, Brussels (Belgium). Cliniques Universitaires St. Luc; Greffe, J.L.; Loncol, T.; Vanneste, F.; Octave-Prignot, M.; Denis, J.M.; De Patoul, N.

    1995-12-01

    Semiconductor dosemeters and thermoluminescence dosemeters were calibrated in view of in-vivo dosimetry. Their response in a 8 MV photon beam and the respective correction factors for the treatment conditions were systematically studied. A total of 249 entrance and exit measurements with this dual detector combination were performed, mainly for treatments of the head and neck region. The resulting entrance and exit doses were compared with the expected doses at these positions, calculated on basis of the treatment and patient parameters. The results at the entrance showed a value of 1.010 (2.8% for the ratio of the measured to the calculated dose by diodes, 1.013) 4.9% for the ratio of the measured to the calculated dose by TLD and 1.003 (3.6% for the ratio of the measured dose by TLD to diodes. With respect the exit dose, the results were 0.998) 4.9%, 1.016 (7.7% and 1.019) 7.0% respectively after correction for the heterogeneity`s. Although the standard deviation for the TLD dosemeters is systematically larger than the standard deviation for the diodes, it is concluded that both dosemeters will yield similar results for-in-vivo dosimetry, if utilized under the same conditions.

  11. MCNP simulation of the incident and Albedo neutron response of the IRD Albedo Neutron Dosemeter for {sup 241}Am-Be moderated sources

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Bruno M.; Martins, Marcelo M.; Mauricio, Claudia L.P.; Mauricio, Claudia L.P. da, E-mail: claudia@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Silva, Ademir X. [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2015-07-01

    The IRD TLD Albedo dosemeter measures both incident and albedo neutron component. The incident to Albedo ratio is used to take into account the energy dependence of its response. In this paper, the behavior of the IRD Albedo dosemeter response as a function of the incident to Albedo ratio for {sup 241}Am-Be sources was simulated to improve its algorithm. The simulation was performed in MCNPX transport code and presents a good agreement with experimental measurements. The results obtained in this work are very useful to improve the accuracy of the IRD Albedo dosemeter at real neutron workplace. (author)

  12. Performance of Panasonic ZP-1460 Electronic Personal Dosemeter under Exposure Conditions Likely to be Found at Fukushima Daiichi Nuclear Power Plant

    Science.gov (United States)

    Tsujimura, Norio; Yoshida, Tadayoshi; Hoshi, Katsuya; Momose, Takumaro

    A study on the performance of the Panasonic ZP-1460 electronic personal dosemeter, the model used in the aftermath of the Fukushima Daiichi nuclear power plant accident in March 2011, was conducted under actual exposure situations likely encountered in the plant. The tests pertained to (1) the dose rate response over dose rates >100 mSv/h and (2) the angular response on an anthropomorphic phantom exposed to the rotational and isotropic irradiation geometries. The test results confirmed that the dosemeter provides Hp(10) as a reasonably close estimate of the effective dose for any exposure geometries. The dosemeter response data evaluated in this study can be utilized for converting dosemeter readings to the absorbed dose to any organs and tissues for epidemiologic purposes.

  13. Measurement analysis using the Fricke dosemeter; Analise de medicoes com o dosimetro Fricke

    Energy Technology Data Exchange (ETDEWEB)

    Pedrosa, G.A.C. [Instituto Nacional de Metrologia (INMETRO), Rio de Janeiro, RJ (Brazil)], e-mail: gcpedrosa@inmetro.gov.br; Dantas, C.C. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear], e-mail: ccd@ufpe.br; Campos, C.A. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)], e-mail: auster@elogica.com.br

    2003-07-01

    The Fricke dosemeter has been used for absolute determination of the radiation dose between 40 and 350 Gy for X-rays, Gamma rays and fast electrons energies. The great inconvenient of that dosimetric system is the impossibility of using for measurements of exposure or low dose rates. A Fricke dosimetry system was implanted at the Nuclear Sciences Regional Center (CRCN), in Recife, Pernambuco state, Brazil, for the determination of radiation doses for spectrometry and mass dosimetry with plasma source. The statistical analysis of the obtained results have shown that using the spectrometric method that system cna be used for maintenance of factors of CRCN standard calibrations and the dose assessment thru mail system of radiotherapy centers of the country.

  14. Automation of radiation dosimetry using PTW dosemeter and LabVIEW{sup TM}

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, C., E-mail: Pscientific1@aec.org.sy [Atomic Energy Commission of Syria, PO Box 6091, Damascus (Syrian Arab Republic); Al-Frouh, K.; Anjak, O. [Atomic Energy Commission of Syria, PO Box 6091, Damascus (Syrian Arab Republic)

    2011-10-21

    Automation of UNIDOS 'Dosemeter' using personal computer (PC) is discussed in this paper. In order to save time and eliminate human operation errors during the radiation dosimetry, suitable software, using LabVIEW{sup TM} graphical programming language, was written to automate and facilitate the processes of measurements, analysis and data storage. The software calculates the calibration factor of the ionization chamber in terms of air kerma or absorbed dose to water according to IAEA dosimetry protocols. It also has the ability to print a calibration certificate. The obtained results using this software are found to be more reliable and flexible than those obtained by manual methods previously employed. Using LabVIEW{sup TM} as a development tool is extremely convenient to make things easier when software modifications and improvements are needed.

  15. Cosmic radiation protection dosimetry using an Electronic personal Dosemeter (Siemens EPD) on selected international flights.

    Science.gov (United States)

    Yasuda, H; Fujitaka, K

    2001-03-01

    The effectiveness of an Electronic Personal Dosemeter (Siemens EPD) for cosmic-radiation dosimetry at aviation altitudes was examined on eight international flights between March and September, 1998. The EPD values (Hepd) of the dose equivalent from penetrating radiation, Hp(10), were assumed to be almost the same as the electron absorbed doses during those flights. Based on the compositions of cosmic radiation in the atmosphere and the 1977 ICRP recommendation, an empirical equation to conservatively estimate the personal dose equivalent (Hp77) at a depth of 5 cm was derived as Hp77 = 3.1 x Hepd. The personal dose equivalent (Hp90) based on the 1990 ICRP recommendation was given by Hp90 = 4.6 x Hepd; the conservative feature of Hp90 was confirmed in a comparison with the calculated effective doses by means of the CARI-6 code. It is thus expected that the EPD will be effectively used for radiation protection dosimetry on selected international flights.

  16. Thermoluminescent dosemeter in a X-ray diffractometer; Dosimetria termoluminiscente en un difractometro de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza A, D.; Gonzalez M, P.; Falcon B, T. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Mexico D.F. (Mexico); Castano, V.M. [Instituto de Fisica, UNAM, Laboratorio Juriquilla, A.P. 1-1010, C.P. 76001, Queretaro (Mexico)

    1999-07-01

    In this work it was presented the results obtained of the dosimetry which was realized in a X-ray diffractometer for powders, trademark Siemens D5000, using the thermoluminescent signal generated by the X-rays in the commercial dosemeter TLD-100 of Harshaw, US. In according to the results obtained, the radiation quantity received by an analysed material in the diffractometer, will be proportional to exposure time and it can vary from unities until tenths of grays. These results are very outstanding when are analysed crystalline materials in a diffractometer, for knowing the present crystalline phases, mainly if these are highly sensitive to the ionizing radiation, as it is the case of the thermoluminescent materials. (Author)

  17. Determination of isodose curves in Radiotherapy using an Alanine/ESR dosemeter; Determinacion de curvas de isodosis en Radioterapia usando un dosimetro de Alanina/ESR

    Energy Technology Data Exchange (ETDEWEB)

    Chen, F.; Baffa, O.; Graeff, C.F.O. [Departamento de Fisica e Matematica. Universidade de Sao Paulo FFCLRP. 14040-901 Ribeirao Preto-SP (Brazil)

    1998-12-31

    It was studied the possible use of an Alanine/ESR dosemeter in the isodose curves mapping in normal treatments of Radiotherapy. It was manufactured a lot of 150 dosemeters with base in a mixture of D-L Alanine dust (80 %) and paraffin (20 %). Each dosemeter has 4.7 mm diameter and 12 mm length. A group of 100 dosemeters of the lot were arranged inside 50 holes of the slice 25 of the phantom Rando Man. The phantom irradiation was realized in two opposed projections (AP and PA) in Co-60 equipment. A group of 15 dosemeters was take of the same lot for obtaining the calibration curve in a 1-20 Gy range. After irradiation the signal of each dosemeter was measured in an ESR spectrometer operating in the X-band ({approx} 9.5 GHz) and the wideness of Alanine ESR spectra central line was correlated with the radiation dose. The wideness dose calibration curve resulted linear with a correlation coefficient 0.9996. The isodose curves obtained show a profile enough similar at comparing with the theoretical curves. (Author)

  18. Measurement of staff doses in interventional procedures using LiF TL-detectors and a special diode dosemeter

    Energy Technology Data Exchange (ETDEWEB)

    Parviainen, T.; Toivonen, M.; Kosunen, A.; Karppinen, J. [Radiation and Nuclear Safety Authority, Helsinki (Finland); Ylitalo, A. [Satakunta Central Hospital, Division for Cardiology, Pori (Finland)

    2003-06-01

    Personal doses vary considerably among the operational staff in cardiac examination procedures and interventions. Correspondingly, the fluoroscopy time may vary from a few minutes to more than 1 hour. Large personal doses in the range of 35 - 41 mSv were registered to some interventional radiologists and cardiologists in 2001 in Finland. Measurement of doses per intervention from hands, shoulders and ankles (parts of the body outside the lead apron) are therefore of interest, but small and highly sensitive dosemeters have not been commonly available for reliable and practical measurements. Thermoluminescent detectors of LiF:MgCu,P are sensitive enough, but residual luminescence from previous uses of detectors and the dose collected from natural background radiation between preparation for use and readout may be significant sources of uncertainty. The company Unfors Instrumens AB (Billdal, Sweden) has designed a light weight diode dosemeter with long cables between detectors and the electronic part for simultaneous measurement of doses from various parts of the body. The aim of this work is to report doses of the operating staff per a cardiac examination or intervention and study the capabilities of the diode dosemeter in staff dose measurements. (orig.)

  19. The Use of Albite as a Dosemeter in Accident Dose Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Correcher, V.; Gomez-Ros, J.M.; Delgado, A

    1999-07-01

    In retrospective accident dosimetry different minerals can be used as dosemeters. In this communication some characteristic features of the thermoluminescence (TL) signal from sodium rich feldspars (albite) are studied. The TL emission spectra from albite (NaAlSi{sub 3}O{sub 8}) shows two characteristic bands peaked at 290 and 390 nm. At these bands, different glow curves presenting rather broad glow peaks are detected. The glow curves at these two wavelengths can be simultaneously recorded during the same readout by a simple device developed in this laboratory. The natural accrued dose is only observed in the high temperature side of the glow curve at 390 nm while the 290 nm glow curve, peaked at lower temperatures, only contains the contribution of young events. From the study and characterisation of the thermal stability of the 290 nm TL curve, it has been possible to obtain accurate dose values, even several months after the accidental irradiation. This determination is made directly from TL measurements without the necessity of subtracting any indirectly estimated dose. (author)

  20. Performance of the EPD-N2 dosemeter for monitoring aircrew doses.

    Science.gov (United States)

    Scherpelz, R I; Cezeaux, J R

    2015-03-01

    United States Air Force (USAF) aircrew fly at altitudes and for durations where doses from cosmic radiation are significant enough to warrant monitoring. This study evaluated a candidate radiological monitoring system for USAF aircrew, the Thermo Scientific electronic personnel dosemeter (EPD-N2). The evaluation consisted of characterising the device in a well-characterised radiation field at a European Organization for Nuclear Research (CERN) accelerator, and aboard an USAF aircraft. The performance of the EPDs was evaluated by comparison with accepted values for dose at the CERN facility, comparison with the value calculated by flight dose software and comparison with the value estimated by a tissue-equivalent proportional counter aboard the aircraft. This study recommends that a correction factor of 1/CF = 1/3.9 be applied to EPD-N2 measurements aboard aircraft flights. The uncertainty in this correction factor is 11.8 %. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Energy and angular dependences of common types of personal dosemeters in the mirror of the First national intercomparison of individual dosimetric monitoring laboratories in Ukraine.

    Science.gov (United States)

    Chumak, V; Deniachenko, N; Volosky, V

    2015-12-01

    In depth analysis of the results of the First National Intercomparison of individual dosimetry laboratories in Ukraine has revealed energy and angular responses of the most common types of personal dosemeters and dosi metric systems. Participating laboratories use 9 different types of dosimetric systems - automatic, semi automat ic and manual. If was found that energy dependences of the most common dosemeter types in Ukraine generally correspond to the literature data on respective TLD materials (LiF:Mg,Cu,P, LiF:Mg,TiandAl2O3:С), however, due to peculiarities of holders (filters) and dose algorithms, for some dosimetry systems the energy dependences can be improved (compensated). Angular dependences proved to be more pronounced: only two systems revealed weak dependence of response on the incident angle, for other systems at large angles (α=60°) dosemeters overestimate true dose values. V. Chumak, N. Deniachenko, V. Volosky.

  2. Al2O3:C as a sensitive OSL dosemeter for rapid assessment of environmental photon dose rates

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Agersnap Larsen, N.; Markey, B.G.

    1997-01-01

    The use of Al2O3:C single crystals as optically stimulated luminescence (OSL) dosemeters for rapid assessment of the environmental photon dose rate is proposed. It is shown that Al2O3:C possesses higher OSL sensitivity than TL sensitivity. In TL measurements thermal quenching is a major problem...... and the energy response (equal to that of quartz) make Al2O3:C ideal for measuring the environmental dose rates in connection with luminescence dating and retrospective dosimetry using natural materials and ceramics. (C) 1997 Elsevier Science Ltd....

  3. Influence of the phantom shape (slab, cylinder or Alderson) on the performance of an Hp(3) eye dosemeter.

    Science.gov (United States)

    Behrens, R; Hupe, O

    2016-03-01

    In the past, the operational quantity Hp(3) was defined for calibration purposes in a slab phantom. Recently, an additional phantom in the form of a cylinder has been suggested for eye lens dosimetry, as a cylinder much better approximates the shape of a human head. Therefore, this work investigates which of the two phantoms, slab or cylinder, is more suitable for calibrations and type tests of eye dosemeters. For that purpose, a typical Hp(3) eye dosemeter was irradiated on a slab, a cylinder and on a human-like Alderson phantom. It turned out that the response on the three phantoms is nearly equal for angles of radiation incidence up to 45° and deviates only at larger angles of incidence. Thus, calibrations (usually performed at 0° radiation incidence) are practically equivalent on both the slab and the cylinder phantoms. However, type tests (up to 75° or even 90° radiation incidence) should be carried out on a cylinder phantom, as also for large angles of incidence the response on the cylinder and the Alderson phantoms is rather similar, whereas the response on the slab significantly deviates from the one on the Alderson phantom. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. About the measurements systems with pen and thermoluminescent dosemeters; Sobre los sistemas de medicion con dosimetros de pluma y los termoluminiscentes

    Energy Technology Data Exchange (ETDEWEB)

    Cortes I, M.E.; Ramirez G, F.P. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152. 07730 Mexico D.F. (Mexico)

    1998-12-31

    In this work it is presented dosimetric data obtained with pen and thermoluminescent dosemeters, which are used by the Occupational Exposure Personnel (OEP) of the Mexican Petroleum Institute (IMP)(1). It was marked several great characteristics as for example, the differences among units which use one and another dosemeter type. Likewise, it is given to know diverse problems that were had in the IMP at relating the data obtained with these dosemeters (which utilizes OEP) and the ICRP 60 recommendations 1990. One of the most important difficulties is to satisfy the recommended limits by ICRP, particularly those that are referring to the units and their complex calculations. With respect to the unities, the ICRP makes reference at the concepts `dose equivalent` and `effective dose` with the sievert unit, that the General Regulations for Radiological Safety associates with `dose equivalent` and `effective dose equivalent`. It was illustrated the type of dosimetric statistics which are obtained with the TLD lectures and a OEP pen dosemeter during 1997. (Author)

  5. Dose profile measurement in computerized axial tomography equipment using thermoluminescent dosemeters; Medicion del perfil de dosis en equipos de tomografia axial computarizada usando dosimetros termoluminiscentes

    Energy Technology Data Exchange (ETDEWEB)

    Azorin V, J.C.; Falcony, C.; Azorin N, J. [Centro de Investigacion en Ciencia y Tecnologia Avanzada, IPN, 07000 Mexico D.F. (Mexico)

    2000-07-01

    In this work are presented the results about measuring the radiation dose profile in two equipment of computerized axial tomography (Tac). Thermoluminescent dosemeters (Dtl) of LiF, Mg, Cu, P + Ptfe in form of disks were used which were developed and made in Mexico. The results showed that Dtl are appropriated for these type of studies. (Author)

  6. Modeling, simulation and measurement of radiation exposure using electronic personal dosemeters on realistic and ICRU phantoms; Modellierung, Simulation und Messung der Strahlenexposition von und mit elektronischen Personendosimetern an realistischen und quaderfoermigen Phantomen

    Energy Technology Data Exchange (ETDEWEB)

    Fuelle, D.; Wahl, W. [GSF Forschungszentrum fuer Umwelt und Gesundheit GmbH, Inst. fuer Strahlenschutz, Neuherberg (Germany)

    2002-07-01

    Studies on realistic phantoms were realized to optimize and understand the personal dose Hp(10) measured with personal dosemeters. Two different voxel phantoms and the dosemeter geometry were simulated to determine the dose distributions. The photon fluence, exposure geometry and photon energy are described in detail. Thereafter, the exposure with external photon rays was simulated on this realistic model. In the next step, the organ dose and the personal dose Hp(10) are described. After all, the dosemeter response function on the phantom is calculated and discussed. (orig.)

  7. Test of ring, eye lens and whole body dosemeters for the dose quantity Hp(3) to be used in interventional radiology

    Science.gov (United States)

    Szumska, A.; Budzanowski, M.; Kopeć, R.

    2017-11-01

    In its statement on tissue reactions approved on 21st April 2011, the International Commission on Radiological Protection (ICRP, 2012) reviewed its recommendation concerning the equivalent dose limit for the eye lens and reduced the dose limits for occupationally exposed persons to 20 mSv in a year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv. This limit was approved and written down in the new EURATOM (European Atomic Energy Community) directive 2013/59 and in the IAEA (International Atomic Energy Agency) BSS (Basic Safety Standard) of July 2014. For that reason, the necessity to monitor the eye lens may become more important than it was before. However, specially dedicated dosemeters for the dose quantity Hp(3) are using very rarely. Commonly use are only whole body personal dosemeters for the personal dose equivalent quantities Hp(10) worn on the trunk and ring dosemeters worn on finger to measure the quantity Hp(0.07). Therefore, in this work it was investigated whether dosemeters from routine use calibrated in terms of Hp(10) and Hp(0.07) and worn on thyroid collar and protective apron could deliver similar results like dedicated eye lens dosemeter worn close to the eyes. The results show that the best method if dedicated eye lens dosimeters is not used is to measure doses in terms of Hp(0.07) on the thyroid collar (Pearson product, r=0.85). Obtained results shows also importance of proper localization of eye lens dosimeter (close to the eye, from side of the X-ray source).

  8. TL response of LiF: Mg, Cu, P dosemeters in function of the photon energy; Respuesta TL de dosimetros de LiF: Mg, Cu, P en funcion de la energia del foton

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, P.R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico); Furetta, C. [Universita degli Studi di Roma ' La Sapienza' , Piazzale Aldo Moro 2, 00185 Roma (Italy)

    2005-07-01

    In this work the obtained results of studying the response of dosemeters of LiF: Mg, Cu, P + Ptfe, developed in the ININ, commercial dosemeters GR200A (LiF: Mg, Cu, P) of chinese manufacture and TLD-100 (LiF: Mg, Ti) US are presented, when irradiating them with X rays 16, 24, 34.5, 42, 100 and 145 keV of effective energy, with gamma rays of 662 keV ({sup 137} Cs) and 1252 keV ({sup 60} Co). The results are presented in function of the sensitivity that the dosemeters showed normalized to gamma radiation of {sup 60} Co. It was appreciated that the dosemeters more equivalent to the tissue, they were those of LiF: Mg, Cu, P + Ptfe, while the less equivalent ones were the TLD-100. (Author)

  9. Use of a robotic manipulator in the simulation of the automation of a calibration process of dosemeters; Uso de un manipulador robotico en la simulacion de la automatizacion de un proceso de calibracion de dosimetros

    Energy Technology Data Exchange (ETDEWEB)

    Benitez R, J.S.; Najera H, M.C. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The development of a system based in a manipulative robot which simulates the operative sequence in a calibration process of dosemeters is presented. In this process it is performed the monitoring of the dosemeter positions and the calibrator by mean of an arm of articulated robot which develops the movement sequences and the taking a decision based on the information coming from the external sensors. (Author)

  10. Use of active dosemeters as a optimization tool in hemodynamics; Uso de dosimetros ativos como ferramenta de otimizacao em hemodinamica

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Rafael; Pereira, Dirceu D. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica; Canevaro, Lucia V. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Rodrigues, Barbara B.D. [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Ferreira, Esmeralci [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Servico de Hemodinamica

    2016-07-01

    Interventional cardiology procedures are, in general, associated with high doses in patients and professionals. The objective of this study is to measure the radiation levels received by professionals .The professional dosimetry was performed in a department of Hemodynamics of University Hospital in Rio de Janeiro. were followed 331 coronary angiography (CA) and 26 percutaneous transluminal coronary angioplasty (PTCA) procedures. For this, were used active dosemeters to measure the radiation levels at the chest of interventional professionals. The results show that average personal equivalent dose of doctors, per procedure was 100 e 154 μSv. On average, nursing technicians and radiologist receive 12 and 10% of doses of physicians, respectively, during CA procedures. From the results, it appears that the doses of hemodynamics exceed the annual dose limit of the standards. The use of lead shielding is presented as an effective action to reduce doses in these workers. (author)

  11. Absorbed dose measurements in mammography using Monte Carlo method and ZrO{sub 2}+PTFE dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Duran M, H. A.; Hernandez O, M. [Departamento de Investigacion en Polimeros y Materiales, Universidad de Sonora, Blvd. Luis Encinas y Rosales s/n, Col. Centro, 83190 Hermosillo, Sonora (Mexico); Salas L, M. A.; Hernandez D, V. M.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Pinedo S, A.; Ventura M, J.; Chacon, F. [Hospital General de Zona No. 1, IMSS, Interior Alameda 45, 98000 Zacatecas (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, IPN, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D. F.(Mexico)], e-mail: hduran20_1@hotmail.com

    2009-10-15

    Mammography test is a central tool for breast cancer diagnostic. In addition, programs are conducted periodically to detect the asymptomatic women in certain age groups; these programs have shown a reduction on breast cancer mortality. Early detection of breast cancer is achieved through a mammography, which contrasts the glandular and adipose tissue with a probable calcification. The parameters used for mammography are based on the thickness and density of the breast, their values depend on the voltage, current, focal spot and anode-filter combination. To achieve an image clear and a minimum dose must be chosen appropriate irradiation conditions. Risk associated with mammography should not be ignored. This study was performed in the General Hospital No. 1 IMSS in Zacatecas. Was used a glucose phantom and measured air Kerma at the entrance of the breast that was calculated using Monte Carlo methods and ZrO{sub 2}+PTFE thermoluminescent dosemeters, this calculation was completed with calculating the absorbed dose. (author)

  12. The relationship between body organ doses and surface dosemeter readings resulting from an infinite area of contamination

    Energy Technology Data Exchange (ETDEWEB)

    Eleftherakis, A. [Aeronautical and Maritime Research Laboratory, Melbourne, VIC (Australia); Rosen, R. [University of New South Wales, Kensington, NSW (Australia). School of Safety Science

    1999-03-01

    Complementary experimental and theoretical techniques were employed to investigate the relationship between radiation doses measured on the surface of the body with those received by internal body organs, for a person standing on an infinite surface uniformly contaminated with gamma emitting radioactive material. This relationship for the critical organs (bone marrow, gastro-intestinal tract and brain) can be used to assess the likely biological response of persons receiving acute or chronic whole body doses of radiation. The experimental technique involved the use of a rotating RANDO phantom which was irradiated with discrete {sup 137}Cs and {sup 60}Co sources placed at successive distances up to 20 m. The experimental dose rates were then extrapolated to derive the equivalent dose rates from an infinite area of contamination. Doses were measured by TLD detectors placed on and inside the phantom. A commercially available Monte Carlo dosimetric computer code, DISDOS-INHOPHO, which incorporated a mathematical phantom, was selected for the theoretical treatment. Extensive modifications were made to the computer code to simulate ground contamination; to account for the transport of photons through air and soil; and to calculate doses delivered to surface dosemeters. The results from the experimental and theoretical work were expressed as organ-to-surface dose ratios and as organ-to-air dose ratios to permit their direct intercomparison. The average of the dose ratio relating the critical organ dose to a surface dosemeter reading had a value of 0.81. Similarly, the dose ratio value for the effective dose had a value of 0.83 7 refs., 1 tab.

  13. Effective dose assessment in the maxillofacial region using thermoluminescent (TLD) and metal oxide semiconductor field-effect transistor (MOSFET) dosemeters: a comparative study

    Science.gov (United States)

    Schulze, D; Wolff, J; Rottke, D

    2014-01-01

    Objectives: The objective of this study was to compare the performance of metal oxide semiconductor field-effect transistor (MOSFET) technology dosemeters with thermoluminescent dosemeters (TLDs) (TLD 100; Thermo Fisher Scientific, Waltham, MA) in the maxillofacial area. Methods: Organ and effective dose measurements were performed using 40 TLD and 20 MOSFET dosemeters that were alternately placed in 20 different locations in 1 anthropomorphic RANDO® head phantom (the Phantom Laboratory, Salem, NY). The phantom was exposed to four different CBCT default maxillofacial protocols using small (4 × 5 cm) to full face (20 × 17 cm) fields of view (FOVs). Results: The TLD effective doses ranged between 7.0 and 158.0 µSv and the MOSFET doses between 6.1 and 175.0 µSv. The MOSFET and TLD effective doses acquired using four different (FOV) protocols were as follows: face maxillofacial (FOV 20 × 17 cm) (MOSFET, 83.4 µSv; TLD, 87.6 µSv; −5%); teeth, upper jaw (FOV, 8.5 × 5.0 cm) (MOSFET, 6.1 µSv; TLD, 7.0 µSv; −14%); tooth, mandible and left molar (FOV, 4 × 5 cm) (MOSFET, 10.3 µSv; TLD, 12.3 µSv; −16%) and teeth, both jaws (FOV, 10 × 10 cm) (MOSFET, 175 µSv; TLD, 158 µSv; +11%). The largest variation in organ and effective dose was recorded in the small FOV protocols. Conclusions: Taking into account the uncertainties of both measurement methods and the results of the statistical analysis, the effective doses acquired using MOSFET dosemeters were found to be in good agreement with those obtained using TLD dosemeters. The MOSFET dosemeters constitute a feasible alternative for TLDs for the effective dose assessment of CBCT devices in the maxillofacial region. PMID:25143020

  14. Effective dose assessment in the maxillofacial region using thermoluminescent (TLD) and metal oxide semiconductor field-effect transistor (MOSFET) dosemeters: a comparative study.

    Science.gov (United States)

    Koivisto, J; Schulze, D; Wolff, J; Rottke, D

    2014-01-01

    The objective of this study was to compare the performance of metal oxide semiconductor field-effect transistor (MOSFET) technology dosemeters with thermoluminescent dosemeters (TLDs) (TLD 100; Thermo Fisher Scientific, Waltham, MA) in the maxillofacial area. Organ and effective dose measurements were performed using 40 TLD and 20 MOSFET dosemeters that were alternately placed in 20 different locations in 1 anthropomorphic RANDO(®) head phantom (the Phantom Laboratory, Salem, NY). The phantom was exposed to four different CBCT default maxillofacial protocols using small (4 × 5 cm) to full face (20 × 17 cm) fields of view (FOVs). The TLD effective doses ranged between 7.0 and 158.0 µSv and the MOSFET doses between 6.1 and 175.0 µSv. The MOSFET and TLD effective doses acquired using four different (FOV) protocols were as follows: face maxillofacial (FOV 20 × 17 cm) (MOSFET, 83.4 µSv; TLD, 87.6 µSv; -5%); teeth, upper jaw (FOV, 8.5 × 5.0 cm) (MOSFET, 6.1 µSv; TLD, 7.0 µSv; -14%); tooth, mandible and left molar (FOV, 4 × 5 cm) (MOSFET, 10.3 µSv; TLD, 12.3 µSv; -16%) and teeth, both jaws (FOV, 10 × 10 cm) (MOSFET, 175 µSv; TLD, 158 µSv; +11%). The largest variation in organ and effective dose was recorded in the small FOV protocols. Taking into account the uncertainties of both measurement methods and the results of the statistical analysis, the effective doses acquired using MOSFET dosemeters were found to be in good agreement with those obtained using TLD dosemeters. The MOSFET dosemeters constitute a feasible alternative for TLDs for the effective dose assessment of CBCT devices in the maxillofacial region.

  15. Determination of the dose index in computerized tomography using thermoluminescent dosemeters; Determinacion del indice de dosis en tomografia computada usando dosimetros termoluminiscentes

    Energy Technology Data Exchange (ETDEWEB)

    Azorin, J.C.; Calderon, A. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-IPN, 11500 Mexico D.F. (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2004-07-01

    In this work the obtained results of the determination of the dose index are presented in thorax studies in computed tomography and helical tomography carried out in Mexico using thermoluminescent dosemeters of LiF: Mg,Cu,P + Ptfe developed and manufactured in our country. The results showed that under similar conditions of irradiation and operation (pitch = 1), significant differences don't exist among the doses absorbed measures in the phantom due to the two types of used tomographs. (Author)

  16. Development of a fibre-optic dosemeter to measure the skin dose and percentage depth dose in the build-up region of therapeutic photon beams.

    Science.gov (United States)

    Kim, K-A; Yoo, W J; Jang, K W; Moon, J; Han, K-T; Jeon, D; Park, J-Y; Cha, E-J; Lee, B

    2013-03-01

    In this study, a fibre-optic dosemeter (FOD) using an organic scintillator with a diameter of 0.5 mm for photon-beam therapy dosimetry was fabricated. The fabricated dosemeter has many advantages, including water equivalence, high spatial resolution, remote sensing and real-time measurement. The scintillating light generated from an organic-dosemeter probe embedded in a solid-water stack phantom is guided to a photomultiplier tube and an electrometer via 20 m of plastic optical fibre. Using this FOD, the skin dose and the percentage depth dose in the build-up region according to the depths of a solid-water stack phantom are measured with 6- and 15-MV photon-beam energies with field sizes of 10 × 10 and 20 × 20 cm(2), respectively. The results are compared with those measured using conventional dosimetry films. It is expected that the proposed FOD can be effectively used in radiotherapy dosimetry for accurate measurement of the skin dose and the depth dose distribution in the build-up region due to its high spatial resolution.

  17. Investigation of dosimetric characteristics of the high sensitivity LiF:Mg,Cu,P Thermoluminescent Dosemeter and its applications in diagnostic radiology - a review

    Energy Technology Data Exchange (ETDEWEB)

    Fung, K.L. E-mail: orkarl@polyu.edu.hk

    2004-05-01

    This study investigated the dosimetric properties of the high sensitivity TLD (Thermoluminescent Dosemeter) of LiF:Mg,Cu,P and its applications in diagnostic radiology. A reproducible readout and annealing regime for this high sensitivity TLD was developed in the initial part of this study with the newly installed automatic TLD Reader system. Basic dosimetric characteristics of this T.L. dosemeter were then investigated. This paved the foundation for subsequent selected novel application studies in diagnostic radiology. This study exploits the favourable dosimetric properties of these T.L. dosemeters in some selected novel dosimetric applications in diagnostic radiology with an anthropomorphic phantom. The applications studied in radiological procedures included: dose reduction in lumbar spine radiography utilizing the 'anode heel effect'; gonad dose variation with kV{sub p} in chest radiography; foetal dose comparison between computed tomography (CT) and computed radiography (CR) in X-ray pelvimetry; lens dose reduction with bismuth eye-shields in CT brain studies; foetal dose assessment of early pregnancy in common high risk radiological examinations. It is anticipated that the unique and favourable dosimetric performance of LiF:Mg,Cu,P T.L. phosphor will be exploited further in measurements of low level dose received by patients and staff in diagnostic radiological procedures such as paediatric X-ray examinations.

  18. Tl response of LiF: Mg, Cu, P + PTFE (Mexico) and GR200A (China) dosemeters; Respuesta Tl de dosimetros de LiF: Mg, Cu, P + PTFE (Mexico) y GR200A (China)

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, P.R. [ININ, A.P. 18-1027, Mexico D.F. (Mexico); Azorin N, J.; Furetta, C. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    TLD-100 was the commercial dosemeter more known since some decades ago. This dosemeter was considered for many research groups as the reference material for developing new Tl materials for ionizing radiation dosimetry. Actually it seems that TLD-100 is going to be replaced by the Chinese material GR200A, as reference material due that this material in addition to be considered as a tissue equivalent material, is 30 to 35 times more sensitive that TLD- 100. Results of the study of the Tl response of LiF: Mg, Cu, P + Ptfe developed at ININ-Mexico, comparing them with those of GR200A are presented. These results showed that the sensitivity (s = Tl intensity/weight x dose) to gamma radiation of the LiF: Mg, Cu, P + Ptfe dosimeters was 4.34 meanwhile that of the commercial dosemeter was 3.41. Detection threshold of the dosemeters studied was 2.22 and 0.52 {mu}Gy respectively Repeatability after 10 cycles Irradiation-reading-annealing was {+-}1.39% and {+-}1.86% respectively. Both types of dosemeters presented a linear response as a function of gamma radiation in the range from 0.02 mGy and 100 Gy. (Author)

  19. NUCLEAR HEATING IN LIF DOSEMETERS IN A FUSION NEUTRON FIELD, TRIAL OF DIRECT COMPARISON OF EXPERIMENTAL AND SIMULATED RESULTS.

    Science.gov (United States)

    Pohorecki, Wladyslaw; Obryk, Barbara

    2017-09-29

    The results of nuclear heating measured by means of thermoluminescent dosemeters (TLD-LiF) in a Cu block irradiated by 14 MeV neutrons are presented. The integral Cu experiment relevant for verification of copper nuclear data at neutron energies characteristic for fusion facilities was performed in the ENEA FNG Laboratory at Frascati. Five types of TLDs were used: highly photon sensitive LiF:Mg,Cu,P (MCP-N), 7LiF:Mg,Cu,P (MCP-7) and standard, lower sensitivity LiF:Mg,Ti (MTS-N), 7LiF:Mg,Ti (MTS-7) and 6LiF:Mg,Ti (MTS-6). Calibration of the detectors was performed with gamma rays in terms of air-kerma (10 mGy of 137Cs air-kerma). Nuclear heating in the Cu block was also calculated with the use of MCNP transport code Nuclear heating in Cu and air in TLD's positions was calculated as well. The nuclear heating contribution from all simulated by MCNP6 code particles including protons, deuterons, alphas tritons and heavier ions produced by the neutron interactions were calculated. A trial of the direct comparison between experimental results and results of simulation was performed. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Measurement of doses to aviator pilots using thermoluminescent dosemeters; Medicion de la dosis a pilotos aviadores usando dosimetros termoluminiscentes

    Energy Technology Data Exchange (ETDEWEB)

    Azorin N, J.; Cruz C, D. [UAM-I, 09340 Mexico D.F. (Mexico); Rivera M, T. [IPN, ESIME Culhuacan (Mexico)]. e-mail: azorin@xanum.uam.mx

    2004-07-01

    During the development of their work, the aviator pilots are exposed at high levels of natural radiation of bottom caused mainly by the cosmic radiation of galactic origin and lot. For such reason, the Metropolitan Autonomous University (UAM) and the Union Association of Aviator Pilots (ASPA), subscribed an agreement with the purpose of to measure the doses of ionizing radiation received by the aviator pilots of diverse air companies that man different types of airships and to determine if these doses surpass the one limit of 0.11 mSv/h settled down by the IAEA for the public in general; and if therefore, these workers should be considered as personnel occupationally exposed. In this work the obtained results when measuring the absorbed dose received by Mexican civil aviator pilots during the development of their work, using thermoluminescent dosemeters of LiF:Mg,Cu,P + Ptfe of national production are presented. The obtained results during the years of 2001 and 2002 show that the monthly doses received by the pilots surpass the one it limits established for the public in general, for what they should be considered as personnel occupationally exposed. (Author)

  1. Assessment of effective radiation dose of an extremity CBCT, MSCT and conventional X ray for knee area using MOSFET dosemeters.

    Science.gov (United States)

    Koivisto, Juha; Kiljunen, Timo; Wolff, Jan; Kortesniemi, Mika

    2013-12-01

    The objective of this study was to assess and compare the organ and effective doses in the knee area resulting from different commercially available multislice computed tomography devices (MSCT), one cone beam computed tomography device (CBCT) and one conventional X-ray radiography device using MOSFET dosemeters and an anthropomorphic RANDO knee phantom. Measurements of the MSCT devices resulted in effective doses ranging between 27 and 48 µSv. The CBCT measurements resulted in an effective dose of 12.6 µSv. The effective doses attained using the conventional radiography device were 1.8 µSv for lateral and 1.2 µSv for anterior-posterior projections. The effective dose resulting from conventional radiography was considerably lower than those recorded for the CBCT and MSCT devices. The MSCT effective dose results were two to four times higher than those measured on the CBCT device. This study demonstrates that CBCT can be regarded as a potential low-dose 3D imaging technique for knee examinations.

  2. The former tests realized to a personal neutron dosemeter based on solid nuclear tracks detector; Primeras pruebas realizadas a un dosimetro personal de neutrones basado en detectores solidos de trazas nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, M.E.; Tavera, L.; Balcazar, M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    Due to the increase in the use of neutron radiation a personal neutron dosemeter based on solid nuclear tracks detector (DSTN) was designed and constructed. The personal dosemeter design consists of three arrangements. The first one consists of a plastic nuclear tracks detector (LR115 or CR39) in contact with a LiF pellet. The second one is the same that above but it placed among two cadmium pellets and, the third one is formed by the alone detector without converter neither neutron absorber. The three arrangements are placed inside a plastic porta detector hermetically closed to avoid the bottom produced by environmental radon whichever both detectors (LR115 and CR39) are sensitive. In this work the former tests realized to that dosemeter are presented. (Author)

  3. Determination of the dose rapidity of a {sup 90} Sr beta radiation source using thermoluminescent dosemeters; Determinacion de la rapidez de dosis de una fuente de radiacion beta de {sup 90}Sr usando dosimetros termoluminiscentes

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, P.R.; Azorin N, J.; Rivera M, T. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    The thermoluminescent dosemeters developed in Mexico, have been used efficiently in environmental and personal dosimetry. When the dose rate of some source is not known can be estimated with the use of thermoluminescent dosemeters taking in account the geometrical array used in the irradiations for reproducibility of the results in posterior irradiations. In this work it was estimated the dose rate of a {sup 90} Sr-{sup 90} Y beta radiation source which is property of the Nuclear Sciences Institute, UNAM, therefore it was l ended to the Metropolitan Autonomous University- Iztapalapa Unit for the characterization of new Tl materials, taking account of the institutional collaboration agreements. (Author)

  4. Influence of the stem effect on radioluminescence signals from optical fibre Al2O3:C dosemeters

    DEFF Research Database (Denmark)

    Marckmann, C.J.; Aznar, M.C.; Andersen, C.E.

    2006-01-01

    to an optical fibre cable that carries the RL and optically stimulated luminescence (OSL) signals generated in the Al2O3:C crystal. During irradiation of the dosemeter, the real-time dose rate can be determined from the RL signal and after irradiation the total dose absorbed is determined from the OSL signal...... stimulated using a focused green solid-state laser. In particular, the components of the stem effect generated in the fibres were analysed to determine their impact on the RL signal....

  5. Effect of some parameters in the response of the Perspex 3042, Lot L amber dosemeters; Efectos de algunos parametros en la respuesta de los dosimetros ambar Perspex 3042, Lote L

    Energy Technology Data Exchange (ETDEWEB)

    Prieto M, E.F.; Barrera G, G. [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN). Calle 30, No. 502, esq. 5ta. Avenida, Playa, Ciudad de La Habana (Cuba)]. e-mail: efprieto@ceaden.edu.cu

    2004-07-01

    The answer of the dosimetric systems is affected by several factors, for what should know as these factors they influence in each one of the different dosimetric systems and by this way to minimize its effect in the value of the absorbed dose and to obtain exact dose values. One of the dosimetric systems more used in the high dose dosimetry like routine dosemeter for the control of the irradiation process are the Perspex dosemeters, for their speed in the obtaining the information, their easy manipulation and the precision that they present. To this dosemeters group they belong the same as the Red and Clear the Amber, which are adequate for the measurement of the radiation dose in the range of high doses. The objective of the present work is to obtain the calibration curves of the dosemeters Amber Perspex 3042, Lot L under our work conditions, like they are the irradiation temperatures and of storage and to know the influence of the rate dose in the value of the absorbed dose for different measurement wavelengths, as well as, the relationship among the one post-irradiation time and the specific absorbance value induced in function of the absorbed dose. (Author)

  6. A method for evaluating the entrance surface dose from the measurement of exposure and half value layer in intraoral radiography using a radiophotoluminescent dosemeter

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, T.; Sasaki, T.; Iwai, K.; Okano, T.; Satoh, K.; Shimano, T.; Hayami, A.; Wado, S.; Juto, N

    2003-07-01

    A method for measuring of entrance surface dose in intraoral radiography for a nationwide survey for the determination of guidance levels was developed using a commercially available radiophotoluminescent dosemeter (RPLD) system. From the ratio readings of the RPLD detectors, with and without a 1 mm thick aluminium filter, half value layer (HVL) and the energy dependency correction factor were derived. HVL and exposure for intraoral radiography were obtained with uncertainties of {+-}0.11 mm Al (SD) and {+-} 2.1% (CV), respectively. This has been achieved by calibration at various beam qualities used in intraoral radiography. The HVLs and outputs of intraoral radiography units were measured by means of the mailed RPLD holder and also by ionisation chambers in 19 dental schools in Japan. Results obtained from the two methods of measurement agreed well for both HVLs and outputs. (author)

  7. New ICRU quantities for the environmental and individual monitoring. Standardization of individual dosemeters by using external beams of photon radiation; Nuevas magnitudes ICRU para la vigilancia radiologica ambiental e individual. Calibracion de dosimetros personales usando haces externos de fotones

    Energy Technology Data Exchange (ETDEWEB)

    Brosed, A.; Delgado, A.; Granados, C. E.

    1987-07-01

    The quantities introduced by ICRU for the radiological monitoring are commented, specially those implied in individual protection against external photons. A procedure is proposed in order to standardize the individual dosemeters by using the kerma in air references of CIEMAT-JEN. The reference radiation beams are described in connection with ISO standards. Provisional values are selected for the appropriate conversion and correction factors. (Author) 23 refs.

  8. Exposure levels to radiation in a nuclear medicine laboratory: measurements with thermoluminescence dosemeters; Niveles de exposicion a la radiacion en un laboratorio de medicina nuclear: mediciones con dosimetros de termoluminiscencia

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz J, A. [Departamento de Medicina Nuclear del Instituto nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Vasco de Quiroga No. 15, Tlalpan 14000 Mexico D.F. (Mexico)

    2000-07-01

    Since 1996 in the Nuclear medicine Department and another routine and research departments of the National Institute of Medical and Nutrition Sciences (INCMNSZ) are working at least with 12 radioactive sources opened and sealed. However, it was unknown if with the Tl personal dosemeters with lithium fluoride crystals (LiF), could be possible to receive information about the equivalent dose for each radionuclide or if there was some radionuclide that by being low energy emissor or beta energy emissor, it did not represent an ionization power sufficient to excite the crystals of the thermoluminescent dosemeters (DTL). In this work the obtained results with control dosemeters of diverse source opened or sealed are shown, which were put at 1 cm of the LiF crystals during a time exposure 18 hours. Therefore the objective of this work is to verify which sources excite or not to DTL crystals and taking the pertinent safety measures for each radionuclide. The conclusion is that the majority of dosemeters were excited by beta or gamma radiation of the radionuclides and that LiF crystals are able to receive equivalent doses until 1200 mSv, being this a guarantee for the staff, that in an any moment could be exposed to high dose in his working day. Also it was corroborated that the radionuclides more energizer are: iodine-131, iodine-125 and sodium-22 while the phosphorus-32 must be managed with careful, since the exposure to hands can result significant, just like the technetium-99m ({sup 99m} Tc). (Author)

  9. Relative thermoluminescent efficiencies proton/gamma and helium/gamma of high temperature peaks in TLD-100 dosemeters; Eficiencias termoluminiscentes relativas proton/gamma y helio/gamma de picos de alta temperatura en dosimetros TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Flores M, E.; Avila, O.; Rodriguez V, M. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico); Massillon, J.L.G.; Buenfil A, E.; Ruiz T, C.; Brandan, M.E. [IFUNAM, 04500 Mexico D.F. (Mexico); Gamboa De Buen, I. [ICN-UNAM, 04500 Mexico D.F. (Mexico)

    2007-07-01

    This work presents measures of relative thermoluminescent efficiency of those high temperature peaks of TLD-100 dosemeters exposed to protons of 1.5 MeV and to helium nuclei of 3 and 7.5 MeV. A rigorous reading and of deconvolution protocol was used for the calculation of the TL efficiencies. Additionally an Excel program that facilitated the deconvolution adjustment process of the glow curves was elaborated. (Author)

  10. Investigation of dosimetric characteristics of the high sensitivity LiF:Mg,Cu,P thermoluminescent dosemeter and its applications in diagnostic radiology

    Energy Technology Data Exchange (ETDEWEB)

    Fung, K.K.L

    2000-12-01

    The recent introduction and development of the thermoluminescent (T.L.) phosphor material LiF:Mg,Cu,P (usually named TLD100H or GR200A) has aroused intense interest of scientists in the field of radiation dosimetry due to its very favourable dosimetric characteristics. Both conventional LiF:Mg,Ti (TLD100) and LiF:Mg,Cu,P T.L. phosphors are tissue-equivalent but GR200A outperforms in respect of its very much higher sensitivity, by a factor of greater than 25, and a dose detection threshold of less than 1 {mu}Gy. A reproducible readout and annealing regime was developed in the initial part of this study with the newly installed automatic TLD (Thermoluminescence Dosimetry) apparatus in the X-ray and Radiation Physics Laboratories of the Hong Kong Polytechnic University. Basic dosimetric characteristics of this T.L. dosemeter (supplied by Harshaw-Bicron Co.) were then investigated. This paved the foundation for subsequent selected novel application studies in diagnostic radiology. Dosimetric characteristics which included linearity, reproducibility, batch uniformity, energy response, and minimum detectable dose were studied using X-rays in the commonly used diagnostic radiology energy range. Favourable dosimetric characteristics were observed from this T.L. phosphor, which agrees well with published studies. The effect of the number of thermal treatment cycles in the initialisation process on dosimetric properties of this T.L. phosphor was also investigated. This study exploits the favourable dosimetric properties of these T.L. dosemeters in some selected novel dosimetric applications in diagnostic radiology with an anthropomorphic phantom using facilities both in these laboratories and also in radiology departments of various district hospitals in Hong Kong. Radiation absorbed dose from the direct or scattered beam, at critical sites inside and on the surface of the phantom, were measured in these radiological studies. The special focus in some of these studies was to

  11. Thermoluminescent response of dosemeters TLD-100 exposed to distinct baker protocols, irradiation and reading; Respuesta termoluminiscente de dosimetros TLD-100 sujetos a distintos protocolos de horneado, irradiacion y lectura

    Energy Technology Data Exchange (ETDEWEB)

    Estrada E, D

    2002-07-01

    The interest that motivated the realization of this work is the opposing discrepancy among the values of the efficiency thermoluminescent of heavy charged particles (PCP) regarding gamma radiation ({eta}{sub PCP}, {gamma}) reported in different works and gathered recently for Horowitz (Ho 01). The measures of relative thermoluminescent efficiency have importance in relation to the dosimetry associated to medical therapy with heavy charged particle. The measurement of {eta}{sub PCP}, {gamma} depends of multiple experimental factors. To understand this dependence it was quantified the effect of using different procedures experimental in the estimate of the relative thermoluminescent efficiency of dosemeters TLD-100 (LiF: Ti; Mg) for protons of 3 MeV regarding gamma rays of {sup 60}Co ({eta}{sub PCP}, {gamma}), varying the lot, the presentation, the one baked and the team reader. When was used the same global procedure values they were obtained for ({eta}{sub PCP}, {gamma}) inside the interval [0.30, 0.58] for the peak 5 and [0.35, 0.76] for the total thermoluminescent signal (Tl). At the use different equipment, baked and lot are obtained maximum differences of 30%, 12% and 6% respectively in the values of ({eta}{sub PCP}, {gamma}) for the peak 5, and 25%, 28% and 7% for the total Tl signal. The changes more significant of 36% and 44% for peak 5 and total signal respectively are obtained when changing the presentation of the dosemeter. As a complementary investigation it was studied the distribution of the Tl signal of each peak in the deconvolution of the curve of brightness with regard to the total signal in exposed dosemeters to high fluence of protons (1x10{sup 10} p/cm{sup 2}) varying the experimental protocol. It was found that the distribution of the Tl signal has a difference of the order of 5% when changing the used reading team. It was observed that the contribution of the peak 5 regarding the total signal are preserved when changing baked and that it

  12. Thermoluminescent and optical processes in alkaline halogenides dosemeters contaminated with Europium; Procesos opticos y termoluminiscentes en dosimetros de halogenuros alcalinos contaminados con Europio

    Energy Technology Data Exchange (ETDEWEB)

    Barboza F, M.; Melendrez, R.; Castaneda, B.; Pedroza M, M.; Chernov, V.; Perez S, R.; Aceves, R. [Centro de Investigacion en Fisica, Universidad de Sonora, A.P. 5-088, 83190 Hermosillo, Sonora (Mexico)

    2000-07-01

    Recent research results are presented about the properties of the optical processes of photo transferred thermoluminescence (TLFT), optical whitening (BO), thermoluminescence induced by light (TLL) and its effect in the thermoluminescent curve (Tl) produced by ionizing and non-ionizing radiation. The systematic analysis of all these processes, acquires a singular importance due that actually the alkaline halogenide crystals are object of intense investigations which analyse their potential applications as detectors and radiation dosemeters through stimulated optical luminescence techniques or thermoluminescence. The obtained data show that the Tl curve of material with this nature can be enormously affected by exposure of phosphorus to the environmental light or UV. This is in part due to liberation processes of charge bearers are shouted and makes a subsequent trapping in less temperature traps; at the same time that induce changes in the intensity of determined Tl bands. Additionally, also it is observed that mentioned phenomena are related as with wavelength of incident light as of the illumination time. Finally, the obtained information allows to conclude that although the illumination effect is extremely complex, it is associated and can be explained mainly with phenomena that implicate the electrons excitation trapped in form of F centers and trapping mechanisms or radioactive and non-radioactive recombination. (Author)

  13. Mensuration of equivalent dose with personal dosemeters and instruments of radiological protection in the new operative magnitudes ICRU, for external fields of beta radiation. Part I. Study of the homogeneity of the response personal dosemeters leaves (cards G-1, TLD-100), in radiation fields of Co{sub 60}; Medicion de dosis equivalente con dosimetros personales e instrumentos de proteccion radiologica en las nuevas magnitudes operativas ICRU, para campos de radiacion beta externos. Parte I. Estudio de la homogeneidad de la respuesta dosimetros personales (tarjetas G-1, TLD-100), en campos de radiacion de Co{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1994-01-15

    A sample of 40 composed personal dosemeters by cards model: G-l, (each card is made up of two TLD-100 crystals encapsulated in teflon), Harshaw trademark; those personal dosemeters present a free window and another with a filter of A1 of 171.7 mg cm{sup -2} of mass thickness.The objective of the work is to select of this sample of 40 personal dosemeters a population with the same stocking and standard deviation. The technique used is that of comparison of stockings, (ANOVA; Variance Analysis, when samples of the same one were had size; and/or GLM, Widespread Lineal Models, when the samples were of different size), by means of the use of those Duncan statistics, SNK, Tukey, Gabriel; the results are validated proving the kindness of adjustment of the experimental data to a Normal distribution by means of the Shapiro-Wilks statistics.The experimental design used consists on a test of two vias: a via is the variable card with two levels, (crystal 1 and 2), the other via is the variable irradiation position with four levels, (LS=left superior, SR= right superior, LI= left Inferior, IR = right inferior). The irradiations carried out in blocks of four personal dosemeters in a gamma radiation beam range of Cobalt 60; carrying out three repetitions of the design. With object of proving the homogeneity of the filter of A1 in those personal dosemeters the experimental design was executed for those cards without personal dosemeters.They were also carried out tests of stockings to the readings of bottom and sensibility of the reader equipment, (Harshaw, model marks 2271), certain that doesn{sup t} exist differences for sequence of reading, but if in the stockings of the sensibility, (they were 4 different populations). The responses of the dosemeters were corrected subtracting him the reading correspondence of bottom and by sensibility of the reader equipment before subjecting them to the tests of stockings mentioned. Of the results of the tests of stockings for the cards with

  14. Exploring gamma radiation effect on exoelectron emission properties of bone

    Energy Technology Data Exchange (ETDEWEB)

    Zakaria, M.; Dekhtyar, Y.; Bogucharska, T.; Noskov, V. [Riga Technical Univ., Biomedical Engineering and Nanotechnology Institute (Latvia)

    2006-07-01

    Gamma radiation is used for radiation therapy to treat carcinogenic diseases including bone cancer. Ionising radiation kills carcinogenic calls. However, there are side effects of the gamma radiation on the bone surface electron structure. One of the effects is in the form of altering electron density of states of bone that, with time, influences biomedical reactions on bone life condition. (authors)

  15. Determination of kinetic parameters in Tl dosemeters of LiF: Mg, Cu, P + PTFE developed in the ININ; Determinacion de parametros cineticos en dosimetros Tl de LiF: Mg, Cu, P + PTFE desarrollados en el ININ

    Energy Technology Data Exchange (ETDEWEB)

    Basurto G, B.S

    2002-07-01

    The objective of this work, is the one of determining the kinetic parameters of the dosemeter of LiF: Mg, Cu, P + Ptfe; starting from the curves Tl obtained at being irradiated with alpha radiation ({alpha}), beta ({beta}) and gamma ({gamma}). As like to compare its sensitivity with each radiation type, considering the sensitivity of the TLD-100 as the unit. In the Chapter 1, the fundamental structure of the matter is described, making emphasis in the different radiation types, and their interaction with this. In the Chapter 2, the units are described but used in the dosimetry of the radiation. In the Chapter 3, the basic concepts of the phenomenon of Tl are described and those are explained characteristic of the deconvolution method to determine the kinetics of the one phenomenon. In the Chapter 4, the methodology is detailed that was used in the elaboration of this thesis work, describing the material Tl that were considered like reference, as well as the sources of ionizing radiation, with those that the dosemeters were irradiated and the equipment in the one that the curves Tl was obtained. Reference is made to the software used to carry out the deconvolution of the curves Tl that were obtained in the one experimental development. In the Chapter 5, the obtained results of this study are presented, showing the tables of homogenization of dosemeters and the reading of the same one; they are observed the curves Tl obtained to different radiation doses (alpha, beta and gamma), the intensity Tl in function of the dose. Also they are tabulated, the obtained results in the kinetic parameters of the three different study materials (TLD-100H, USA; TLD-100, USA and LiF: Mg, Cu, P + Ptfe developed in the l.N.l.N). They are analyzed shortly for each material Tl their sensitivity to the ionizing radiation as well as their kinetic parameters. The obtained results showed that the Tl dosemeters of LiF: Mg,Cu,P + Ptfe, they presented a bigger sensitivity that the TLD-100 when

  16. Obtention of thermoluminescent efficiencies by means of irradiation of TLD-100 dosemeters with proton beams helium and carbon; Obtencion de eficiencias termoluminiscentes mediante irradiacion de dosimetros TLD-100 con haces de protones, helios y carbon

    Energy Technology Data Exchange (ETDEWEB)

    Avila, O.; Rodriguez V, M.; Aviles, P.; Gamboa de Buen, I.; Buenfil, A.E.; Ruiz T, C.; Brandan, M.E. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    In this work, the advances of a serial of measurements of relative efficiency thermoluminescent of heavy charged particles (PCP) with respect to gamma radiation for TLD-100, dosemeters of LiF: Mg,Ti manufactured by the Harshaw-Bicron company are reported. The PCP are essentials in the implementation of dosimetry associated with medical applications. The measurements before gamma radiation were carrying out using the Vickrad irradiator of the National Institute of Nuclear Research at dose of 1.663 Gy. The measures which are reported about protons, helium and carbon were realized using the Pelletron accelerator of the Physics Institute of the UNAM. (Author)

  17. Energy response of different types of RADOS personal dosemeters with MTS-N (LiF:Mg,Ti) and MCP-N (LiF:Mg,Cu,P) TL detectors.

    Science.gov (United States)

    Obryk, B; Hranitzky, C; Stadtmann, H; Budzanowski, M; Olko, P

    2011-03-01

    The photon energy response of different RADOS (Mirion Technologies) personal dosemeters with MTS-N (LiF:Mg,Ti) and MCP-N (LiF:Mg,Cu,P) thermoluminescence (TL) detectors was investigated. Three types of badges were applied. The irradiation with reference photon radiation qualities N (the narrow spectrum series), and S-Cs and S-Co nuclide radiation qualities, specified in ISO 4037 [International Organization for Standardization (ISO). X and gamma reference radiations for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy. ISO 4037. Part 1-4 (1999)], in the energy range of 16-1250 keV, were performed at the Dosimetry Laboratory Seibersdorf. The results demonstrated that a readout of a single MTS-N or MCP-N detector under the Al filter can be used to determine Hp(10) according to requirements of IEC 61066 [International Electrotechnical Commission (IEC). Thermoluminescence dosimetry systems for personal and environmental monitoring. International Standard IEC 61066 (2006)] for TL systems for personal dosimetry. The new RADOS badge with the experimental type of a holder (i.e. Cu/Al filters) is a very good tool for identifying the radiation quality (photon energy).

  18. Batch homogeneity of LiF(Mg,Cu,P)-GR200 and LiF(Mg,Cu,P)-MCP-NS TL detectors for use as extremity dosemeters at ENEA personal dosimetry service.

    Science.gov (United States)

    Mariotti, F; Uleri, G; Fantuzzi, E

    2006-01-01

    The results of a study of two commercially available LiF(Mg,Cu,P) TL materials, a GR200 detector and a MCP-Ns thin detector, are described in order to use these phosphors for individual monitoring for the extremities. After a dosimetry system has been type tested, the implementation routine is not straightforward. Additional tests and software modification are needed to make the routine system work comply with the type test results. Not often can literature be found on the steps required to implement the results in a routine study. This paper reports the results of the individual calibration of about 15 000 extremity dosemeters, 12 000 containing a GR200 detector and 3000 an MCP-Ns thin detector. It describes the experimental procedure followed in order to assure reproducibility and stability of the results with proper accuracy and reliability. In particular, this is the first time that results on homogeneity of such a large batch of MCP-Ns detectors are reported.

  19. The ferrous ammonium sulfate solid system, as dosemeter for processes at low temperatures and high doses of gamma radiation; El sistema sulfato ferroso amoniacal solido, como dosimetro para procesos a bajas temperaturas y altas dosis de radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Juarez C, J.M.; Ramos B, S.; Negron M, A. [ICN-UNAM, 04510 Mexico D.F. (Mexico)

    2005-07-01

    This paper presents the results obtained from a study of the radiation induced oxidation of crystalline ferrous ammonium sulfate with gamma rays at 295 K, 263 K and 77 K and dose from 0 to 300 kGy. The radiation induced decomposition of ferrous ammonium sulfate has been studied by the dissolution of the irradiated salt in 0,8 N sulfuric acid. The main product is Fe{sup 3+} and molar concentration of ferric ion was determined spectrophotometrically in the UV region at 304 nm. The optical density values showed a linear dependence with dose, indicating that the data obtained might be used to create a calibrating curve. Color in irradiated salt changes from blue to green, yellow and orange according to the absorbed dose. The accuracy and the reproducibility of the system were tested. In addition, some other characteristics make possible the use of this system as a dosimeter, similar to Fricke chemical dosemeter, at low temperatures and high dose. (Author)

  20. Comparison of two models for the X-ray dispersion produced in a Novillo Tokamak with measurements make with thermoluminescent dosemeters; Comparacion de dos modelos para la dispersion de rayos X producidos en un Novillo Tokamak con mediciones efectuadas con dosimetros termoluminiscentes

    Energy Technology Data Exchange (ETDEWEB)

    Flores O, A.; Castillo, A.; Barocio, S.R.; Melendez L, L.; Chavez A, E.; Cruz C, G.J.; Lopez, R.; Olayo, M.G.; Gonzalez M, P. [Instituto Nacional de Investigaciones Nucleares, 52045 Salazar, Estado de Mexico (Mexico); Azorin N, J. [Universidad Autonoma Metropolitana Iztapalapa, 09340 Mexico D.F. (Mexico)

    1999-07-01

    It was presented the results to study about the X-ray dispersion produced in the Novillo Tokamak using thermoluminescent dosemeters (DTL). The measurements were make in the equatorial plane of Tokamak, along twelve radial directions. The dispersion is observed due to the radiation interaction with walls surrounding the machine. It was proposed two types of heuristic mathematical methods for describing the X-ray dispersion, comparing them with the experimental data obtained with Dtl. The predictions of both models are adjusted well to the experimental data. (Author)

  1. Relative thermoluminescent efficiencies proton/gamma and helium/gamma of peaks of high temperature in TLD-100 dosemeters; Eficiencias termoluminiscentes relativas proton/gamma y helio/gamma de picos de alta temperatura en dosimetros TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Flores M, E. [UNAM, Facultad de Ciencias, 04510 Mexico D.F. (Mexico)

    2007-07-01

    The increase of the applications of ion beams in radiotherapy treatments has generated interest in the study of the thermoluminescent materials (TL) that allow to determine the applied doses. A way to quantify the TL response from these materials to ions is by means of the relative thermoluminescent efficiency. In the group of Thermoluminescent dosimetry of the Institute of Physics of the UNAM (IFUNAM) the thermoluminescent response of the TLD-100 dosemeters has been studied, which present a glow curve characteristic with several peaks that correspond to traps and luminescent centers in the material. The stable peaks know each other as 4, 5, 6a, 6b, 7, 8, 9 and 10. The efficiencies should be measured using the response so much to the radiation of interest (in this case protons and helium ions) as the response to gamma radiation. In previous works with ions of low energy taken place in the Pelletron accelerator of the IFUNAM was only measured the TL efficiency for the peak 5 and the total signal. It had not been possible to measure the efficiency of the peaks of high temperature (6a-10) because, for the gamma radiation, the peaks of high temperature show very small signals; however, recently Massillon carries out measures of efficiency TL of peaks of high temperature for ions of intermediate energy using a protocol special of reading and of deconvolution that allows to measure the signals coming from the peaks of high temperature. In this work is implemented this same protocol to complete the study of TL efficiencies at low energy of protons and helium and to determine if the values of efficiency depend on the used reading protocol. For it is reported it measures of the relative efficiency of the peaks of high temperature from the TLD-100 exposed to protons of 1.5 MeV and nuclei of helium of 3 and 7.5 MeV. (Author)

  2. Mensuration of equivalent dose with personal dosemeters and instruments of radiological protection in the new operative quantities ICRU, for external fields of beta radiation. Part II. I study of the angular response of personal dosemeters TLD-100 in secondary patron fields of beta radiation ({sup 90}Sr / {sup 90}Y); Medicion de dosis equivalente con dosimetros personales e instrumentos de proteccion radiologica en las nuevas magnitudes operativas ICRU, para campos de radiacion beta externos. Parte II. Estudio de la respuesta angular de dosimetros personales TLD-100 en campos patrones secundarios de radiacion beta ({sup 90}Sr/{sup 90}Y)

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1994-01-15

    The objective of this work is to carry out one of the possible ones test type for personal dosemeters TLD, under the recomendations of the ICRU 39, ICRU 43 and the draft of the norm ISO 6980,(1992), with the purpose of verifying the capacity of these detectors to carry out the operative unit: H' (0.07;{alpha}). Since H' (O. 07;{alpha}) this defined one in an expanded field, one of these tests type consist on determining the angular response of these detectors. 20 personal dosemeters TLD-100 was used, (card marks: Harshaw, Model: G-1, with two glasses of TLD-100 absorbed in teflon; the portadosemeters has two windows, a free one and another with a filter of Pb of 171.0 mg cm{sup -2}); these dosemeters they were previously selected, [to see, {sup S}tudy of the Homogeneity of the response of Personal Dosemeters (Cards G-l, TLD-100) in Radiation of Countrysides of {sup 60}Co{sup ,} J.T. Alvarez R. Technician Report GSR/IT/0001/94].The irradiations to effectued in secondary countryside of radiation beta of {sup 90}Sr/{sup 90}Y. The study was undertaken by means of an experimental design of blocks random that contemplate the following variables: intensity of the radiation source, (1850 MBq and 74 MBq); position of irradiation, (four positions); incidence of angle of the radiation (0, 15, 30, 45, 60 and 75 grades) and the absorbed dose in air, (0.005, 0.010, 0.020, 0.050 and 0.100 Gy). Then null hypothesis it was to suppose that there was not difference among the stockings of each treatment, to used the statistical of Duncan to carry out tests of stockings at a level of significance of 5%.These tests of stockings throw the following results in those variables of the experimental design: The irradiations carried out so much with the source pattern secondary of {sup 90}Sr/{sup 90}Y of 1850 MBq and of 74 MBq, they are equivalent reason why they can be used indistinctly. The responses of each one of the glasses of the card are strongly anisotropic for each glass

  3. Charge movement in grains of quartz studied using exo-electron emission

    DEFF Research Database (Denmark)

    Ankjærgaard, Christina; Denby, Phil M.; Murray, A.S.

    2008-01-01

    movement in luminescence phosphors. Here we show that OSE from natural quartz grains gives an easily detectable, reproducible and light sensitive signal, although it is not as intense as OSL. A single sample of natural quartz grains extracted from a sediment is used to investigate the thermal stability...

  4. Clay as Thermoluminescence Dosemeter in diagnostic Radiology ...

    African Journals Online (AJOL)

    This paper reports the investigation of the basic thermoluminescence properties of clay at x-rays in the diagnostic radiology range, including dose monitoring in abdominal radiography. Clay sourced from Calabar, Nigeria, was tested for thermoluminescence response after irradiation at diagnostic radiology doses, including ...

  5. HSP as bio dosemeters; HSP como biodosimetros

    Energy Technology Data Exchange (ETDEWEB)

    Manzanares A, E.; Vega C, H.R. [Grupo Academico de Radiobiologia, UAZ, A.P. 336, 98000 Zacatecas (Mexico)

    2005-07-01

    A review of the more important passages for the field of the radiological protection, from the discovery, beginnings of the utilization of the radiations emitting, passing to the legislation proposals and the transformations that had been suffer to establish the international standards of radiological protection. The paradigms on the effects and chronologically the emanated discoveries of the cellular research and the measurement of cellular products in the species and the diverse alive beings making emphasis in evaluating the expression of the heat-shock proteins caused by low doses of gamma radiation, these are used as radiation bio monitors and of other agents that cause cellular stress and lastly a prospective of the future of the radiobiology. (Author)

  6. Calibration of photographic dosemeters to evaluate the personal equivalent dose, Hp (10), irradiated by different radiation qualities and angles of incidence; Calibracao de dosimetros fotograficos para avaliar o equivalente de dose pessoal, Hp(10), irradiados por diferentes qualidades de radiacao e angulos de incidencia

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, Christiana; Antonio Filho, Joao, E-mail: chsantoro@gmail.com, E-mail: jaf@ufpe.br [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Santos, Marcus Aurelio P.; Goncalves Filho, Luiz Carlos, E-mail: masantos@cnen.gov.br, E-mail: l.filho@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, Pe (Brazil)

    2013-07-01

    To use radiation detectors, should periodically perform tests and calibrations on instruments in order to verify its good functionality. One way to ascertain the quality of the instrument is to conduct a study of the angular dependence of the response of the radiation detectors. The photographic dosimetry has been used widely to quantify the radiation doses and to estimate levels of doses received by workers involved with X-and gamma radiation. Photographic dosimeters are used because provide wide range of exposure and good accuracy. One of the sources of error have been introduced by different irradiation geometries between calibration and measurement in radiation fields used in x-ray and gamma ray sources, therefore, there is a need for an evaluation of the sensitivity of dosimeters with variation of the angle of the incident beam. In this study were tested 190 photographic dosemeters in the Metrology Laboratory of the Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE) using the phantom H{sub p} (10), where the dosimeters are evaluated on the basis of the new operational magnitude for individual monitoring, the equivalent personal dose, H{sub p} (10). Angular dependence of these radiation detectors was studied in X radiation fields (in the range of 45 keV energy to 164 keV) and gamma radiation ({sup 137}Cs-662 keV e {sup 60}Co - 1250 keV)

  7. Dosimetry of low-energy beta radiation

    Energy Technology Data Exchange (ETDEWEB)

    Borg, J.

    1996-08-01

    Useful techniques and procedures for determination of absorbed doses from exposure in a low-energy {beta} radiation field were studied and evaluated in this project. The four different techniques included were {beta} spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical low-energy {beta} radiation field a moderated spectrum from a {sup 14}C source (E{sub {beta}},{sub max} =156 keV) was chosen for the study. The measured response of a Si(Li) detector to photons (bremsstrahlung) showed fine agreement with the MC calculated photon response, whereas the difference between measured and MC calculated responses to electrons indicates an additional dead layer thickness of about 12 {mu}m in the Si(Li) detector. The depth-dose profiles measured with extrapolation chambers at two laboratories agreed very well, and it was confirmed that the fitting procedure previously reported for {sup 147}Pm depth-dose profiles is also suitable for {beta} radiation from {sup 14}C. An increasing difference between measured and MC calculated dose rates for increasing absorber thickness was found, which is explained by limitations of the EGS4 code for transport of very low-energy electrons (below 10-20 keV). Finally a study of the thermally stimulated exoelectron emission (TSEE) response of BeO thin film dosemeters to {beta} radiation for radiation fields with maximum {beta} energies ranging from 67 keV to 2.27 MeV is reported. For maximum {beta} energies below approximately 500 keV, a decrease in the response amounting to about 20% was observed. It is thus concluded that a {beta} dose higher than about 10 {mu}Gy can be measured with these dosemeters to within 0 to -20% independently of the {beta}energy for E{sub {beta}},{sub max} values down to 67 keV. (au) 12 tabs., 38 ills., 71 refs.

  8. Preliminary results on bubble detector as personal neutron dosemeter.

    Science.gov (United States)

    Ponraju, D; Krishnan, H; Viswanathan, S; Indira, R

    2011-03-01

    The bubble detector is demonstrated as one of the best suitable neutron detectors for neutron dose rate measurements in the presence of high-intense gamma fields. Immobilisation of a volatile liquid in a superheated state and achieving uniform distribution of tiny superheated droplets were a practical challenge. A compact and reusable bubble detector with high neutron sensitivity has been developed at the Indira Gandhi Centre for Atomic Research by immobilising the superheated droplets in a suitable polymer matrix. Two types of bubble detectors have been successfully developed, one by incorporating isobutane for measuring fast neutron and another by incorporating Freon-12 for both fast and thermal neutron. The performance of the detector has been tested using 5 Ci Am-Be neutron source and the results are described.

  9. Dose measurement in periapical radiographic exams using dosemeter pen: a look at the radioprotection

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Renato; Ferreira, Vanessa, E-mail: vanessamachado@ufmg.br [Curso Superior de Tecnologia em Radiologia. Faculdade de Medicina. Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Pereira, Claubia; Oliveira, Arno H.; Veloso, M.A.F., E-mail: gbarros@nuclear.ufmg.br, E-mail: claubia@nuclear.ufmg.br, E-mail: heeren@nuclear.ufmg.br, E-mail: Dora@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear

    2011-07-01

    The use of radiology has been a large increase with the crescent accessibility to dental care, orthodontics and aesthetic. Besides the increase in the number of exams, there was an increase in radiation dose during dental exams such as computed tomography. The objective of this work is to evaluate the radiation dose to which the patient is subjected in a peri apical dental radiography. The dose values were measured with a dosimeter pen during radiographs in real exams peri apical with the X-ray equipment Timex 70 C Gnatus. During the exams realization, was maintained, in the holder, the dosimeter pen near to the region of interest. The values collected were recorded in dosimeter pen. These values were compared with the reference doses of the Portaria 453 of ANVISA, this procedure allows to verify if the recommended dose limits for this exam are being respected. These data indicates if the used equipment is calibrated and in good condition of use. It was performed a comparison between the obtained experimental dose values and the values found from computer simulation with the code MCNPX 2.6.0. (author)

  10. Thermoluminescence solid-state nanodosimetry—the peak 5A/5 dosemeter

    Science.gov (United States)

    Fuks, E.; Horowitz, Y. S.; Horowitz, A.; Oster, L.; Marino, S.; Rainer, M.; Rosenfeld, A.; Datz, H.

    2011-01-01

    The shape of composite peak 5 in the glow curve of LiF:Mg,Ti (TLD-100) following 90Sr/90Y beta irradiation, previously demonstrated to be dependent on the cooling rate used in the 400°C pre-irradiation anneal, is shown to be dependent on ionisation density in both naturally cooled and slow-cooled samples. Following heavy-charged particle high-ionisation density (HID) irradiation, the temperature of composite peak 5 decreases by ∼5°C and the peak becomes broader. This behaviour is attributed to an increase in the relative intensity of peak 5a (a low-temperature satellite of peak 5). The relative intensity of peak 5a is estimated using a computerised glow curve deconvolution code based on first-order kinetics. The analysis uses kinetic parameters for peaks 4 and 5 determined from ancillary measurements resulting in nearly ‘single-glow peak’ curves for both the peaks. In the slow-cooled samples, owing to the increased relative intensity of peak 5a compared with the naturally cooled samples, the precision of the measurement of the 5a/5 intensity ratio is found to be ∼15 % (1 SD) compared with ∼25 % for the naturally cooled samples. The ratio of peak 5a/5 in the slow-cooled samples is found to increase systematically and gradually through a variety of radiation fields from a minimum value of 0.13±0.02 for 90Sr/90Y low-ionisation density irradiations to a maximum value of ∼0.8 for 20 MeV Cu and I ion HID irradiations. Irradiation by low-energy electrons of energy 0.1–1.5 keV results in values between 1.27 and 0.95, respectively. The increasing values of the ratio of peak 5a/5 with increasing ionisation density demonstrate the viability of the concept of the peak 5a/5 nanodosemeter and its potential in the measurement of average ionisation density in a ‘nanoscopic’ mass containing the trapping centre/luminescent centre spatially correlated molecule giving rise to composite peak 5. PMID:21149323

  11. Response of TL dosemeters to cosmic radiation on board passenger aircraft

    CERN Document Server

    Bilski, P; Marczewska, B; Olko, P

    2002-01-01

    Measurements were performed with various LiF based TLDs on board seven Polish aircraft, flying long-distance or middle-distance routes. All of the /sup 7/LiF detectors used (various types of /sup 7 /LiF:Mg, Ti and /sup 7/LiF:Mg, Cu, P detectors), which measure the non-neutron component of the radiation field, produced consistent results. It was found that the characteristics of the TLD response (ratio of different detector responses, glow curve shapes) after doses of radiation at flying altitudes differ from those obtained after exposure at the CERN facility (CERF), suggesting a lower contribution of densely ionising radiation. The neutron induced TL signal was also more affected by the thickness of the holder, suggesting the presence of a softer neutron energy spectrum at flight altitudes. Further in-flight and CERF exposures of detectors are planned to resolve these issues. (5 refs).

  12. First Calibrations of Alanine and Radio-Photo-Luminescence Dosemeters to a Hadronic Radiation Environment

    CERN Document Server

    Fürstner, Markus; Floret, Idelette; Forkel-Wirth, Doris; Mayer, Sabine; Menzel, Hans Gregor; Vincke, Helmut H

    2005-01-01

    Alanine and Radio-Photo-Luminescence (RPL) dosimeters are used to monitor radiation doses occurring inside the tunnels of all CERN accelerators including the Large Hadron Collider (LHC). They are placed close to radiation sensitive machine components like cables or insulation of magnet coils to predict their remaining lifetime. The dosimeters are exposed to mixed high-energy radiation fields. However, up to now both dosimeter types are calibrated to 60Co-photons only. In order to study the response of RPL and alanine dosimeters to mixed particle fields like those occurring at CERN's accelerators, an irradiation campaign at the CERN-EC High-Energy Reference field Facility (CERF-field) was performed. Moreover, the dosimeters were first time calibrated to a proton radiation field of a constant momentum of 24 GeV/c. In addition to the experiment FLUKA Monte Carlo simulations were carried out, which provide information concerning the energy deposition and the radiation field at the dosimeter locations.

  13. The design and implementation of the DIRK system for dosemeter issue and record keeping

    CERN Document Server

    Kendall, G M; Kay, P; Law, D V; Salmon, L; Saw, G M A

    1983-01-01

    DIRK, the computerised system which the National Radiological Protection Board employs for its Personal Monitoring Service, is described. DIRK is also used to store the data for the National Registry for Radiation Workers and could support the Central Index of Dose Information should this be set up. The general principles of the design of DIRK, as well as a detailed description of the system, are included in the report. DIRK is based on a set of interlocked index sequential files manipulated by PL/1 programs. Data compaction techniques are used to reduce by a factor of ten the size of the files stored on magnetic disk. Security of the database is most important and two levels of security have been implemented. Table driven techniques are used for updating the database. A specially designed free-format language is used for specifying changes. Statistics, sorted listings of selected data and summaries are provided by a general purpose program for this type of operation. However, it has still been necessary to w...

  14. Electron-trapping probability in natural dosemeters as a function of irradiation temperature

    DEFF Research Database (Denmark)

    Wallinga, J.; Murray, A.S.; Wintle, A.G.

    2002-01-01

    The electron-trapping probability in OSL traps as a function of irradiation temperature is investigated for sedimentary quartz and feldspar. A dependency was found for both minerals; this phenomenon could give rise to errors in dose estimation when the irradiation temperature used in laboratory...... procedures is different from that in the natural environment. No evidence was found for the existence of shallow trap saturation effects that Could give rise to a dose-rate dependency of electron trapping....

  15. Study and development of new dosemeters for thermal neutrons; Estudio y desarrollo de nuevos dosimetros para neutrones termicos

    Energy Technology Data Exchange (ETDEWEB)

    Urena N, F

    1998-12-31

    An alanine-boron compound, alanine hydroborate, was synthesized and chemically characterized to be used for thermal neutrons fluence measurements. The synthesis of the compound was made by reacting the amino acid alanine with boric acid in three different media: acidic, neutral and alkaline. Physicochemical analysis showed that the alkaline medium is favorable for the synthesis of the alanine hydroborate. The compound was evaluated as a thermal neutron fluence detector by the detection of the free radical yield upon neutron thermal irradiation by Electron Paramagnetic Resonance (EPR). The present work also studies the EPR-signal response of the three preparations to thermal neutron irradiation ({phi} = 5 x 10{sup 7} n/cm{sup 2} -s). The following EPR signal parameters of the samples were investigated: peak-to-peak signal intensity vs. thermal neutron fluence {Phi} = {phi} {Delta}t ; where {Delta}t = 1, 5, 10, 20, 40, 60, 80, 90, 100, 110 and 120 h. , peak-to-peak signal intensity vs. microwave power, signal fading; repeatability, batch homogeneity, stability and zero dose response. It is concluded that these new products could be used in thermal neutron fluence estimations. (Author)

  16. Evaluation of influence quantities in the semiconductor dosemeters calibration;Avaliacao de grandezas de influencia na calibracao de dosimetros semicondutores

    Energy Technology Data Exchange (ETDEWEB)

    Petri, Anna R. [Pontificia Universidade Catolica (PUC/SP), Sao Paulo, SP (Brazil). Curso de Fisica Medica; Terini, Ricardo A. [Pontificia Universidade Catolica (PUC/SP), Sao Paulo, SP (Brazil). Dept. de Fisica; Pereira, Marco A.G. [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Inst. de Eletrotecnica e Energia

    2009-07-01

    Semiconductor dosimeters are an alternative to the ionization chambers in diagnostic radiology, because they do not require corrections for atmospheric pressure, are rigid and produces a more large signal than ionization chambers. However, these dosimeters, in general, exhibit strong energy dependence. To perform the calibration of dosimeters it has been adopted, in this work, the 'substitution method', proposed by International Atomic Energy Agency (IAEA) in document TRS number 457. In this method, the air kerma rate measured by the dosimeter to be calibrated is compared with that of an ionization chamber previously calibrated for standard X-ray beams. The present study describes the results concerning the 'substitution method' implementation for semiconductor detectors calibration and the influence quantities evaluation in the calibration of dosimetric systems (detector and electrometer). (author)

  17. Influence of temperature in polymethylmethacrylate (PMMA) dosemeters response; Influencia da temperatura na resposta de dosimetros de polimetilmetacrilato (PMMA)

    Energy Technology Data Exchange (ETDEWEB)

    Napolitano, Celia Marina; Ferreira, Danilo Cardenuto; Camargo, Fabio de; Goncalves, Josemary Angelica Correa; Tobias, Carmen Cecilia Bueno [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2005-07-01

    The use of gamma irradiation sterilization processes in medical products and food preservation has encouraged the emergence of industrial facilities responsible for generation of doses as high as a few dozen kGy. The characterization of this radiation field requires the use of dosimeters with high spatial resolution, high resistance to radiation damage, maintenance of information absorbed doses at a time suitable for the analysis and processing of data, easy handling, etc. The dosimeters that meet most of these requirements are based on polymethylmethacrylate (PMMA) with dyes sensitive to radiation. The dose that can be measured with these dosimeters extends from 100Gy to 50kGy, with the estimated accuracies by manufacturers from 2 to 3%. However, in practice, there are procedures that require irradiation in different conditions of temperature, which results in changes in the response of the dosimeter. This way, considering the irradiations made in the center of radiation technology of Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP - Brazilian nuclear and energy research institute -, has studied the effect of temperature on the response of routine dosimeters PMMA type where the operational characteristics of Gammachrome YR dosimeters type and Red Perspex are being investigated respect to temperature and dose, whose results will be presented in this paper.

  18. Measurements of radon in dwellings with CR-39 track detectors

    DEFF Research Database (Denmark)

    Majborn, Benny

    1986-01-01

    A passive integrating dosemeter has been designed for measuring natural radiation in dwellings. The dosemeter contains one or two CR-39 track detectors to measure radon and three thermoluminescence dosemeters to measure external radiation. The dosemeter was investigated in a pilot study in 1983/8...

  19. Thermoluminescent dosemeters characterization for patient dosimetry in diagnostic radiology preliminary results;Caracterizacao de dosimetros termoluminescentes para dosimetria de pacientes em radiodiagnostico - resultados iniciais

    Energy Technology Data Exchange (ETDEWEB)

    Castro, William J.; Squair, Peterson L. [Faculdade Novo Rumo, Belo Horizonte, MG (Brazil); Centro de Desenvolvimento de Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Gonzaga, Natalia B. [Universidade Unincor, Belo Horizonte, MG (Brazil); Centro de Desenvolvimento de Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Nogueira, Maria S.; Silva, Teogenes A. da [Centro de Desenvolvimento de Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2009-07-01

    The determination of the metrological characteristics of thermoluminescent (TL) dosimeters plays an important role in dosimetry of patients submitted to x-ray examinations for diagnostic purpose. Entrance surface doses can be measured with TL dosimeters to verify the compliance with the diagnostic reference levels. Organ doses can be estimated through TL measurements in an anthropomorphic phantom which it allows the radiation risk assessment. In this work, LiF:Mg,Ti (TLD-100) rod and chip thermoluminescent dosimeters were characterized considering their use for patient dosimetry in computerized tomography and mammography. Preliminary results showed that TL dosimeters have a response reproducibility of 7.8% and 4.8% and homogeneity of 18.4% and 6.5% for rod and chip shapes, respectively. (author)

  20. Development and characterization of ultra-thin dosemeters of aluminium oxide; Desarrollo y caracterizacion de dosimetros ultra-delgados de oxido de aluminio

    Energy Technology Data Exchange (ETDEWEB)

    Villagran V, E

    2003-07-01

    The aim of the present thesis work has been to investigate the thermoluminescent (Tl) response of aluminium oxide thin films with thicknesses of the order of 300 nm prepared by laser ablation. Aluminium oxide thin films show Tl response after they are subject to ultraviolet, beta and gamma radiation. The Tl curves exhibit peaks around 75 C and 169 C for UV radiation, 112 C and 180 C for beta particles and 110 C and 176 C for gamma radiation. In order to improve the Tl response some growth parameters such as power density and distance target-substrate were varied. The relation dose-response shows a non-linear behavior for UV irradiation; a linear behavior for beta-particles dose from 150 mGy to 50 Gy, and a linear behavior for gamma radiation dose from 5 Gy to 100 Gy. The kinetic Tl parameters were determined by Computerized Glow Curve Deconvolution (CGCD) method as well as using analytical methods. The CGCD results show that the high temperature peak is composed by four peaks with maximums in 165.7, 188.1, 215.3, 246.5 C. These obey a second order kinetics. The trap depth (E) values are 1.4, 1.6, 1.8 and 2.0 eV respectively. The different analytical results show a trap depth values of 0.914, 0.82 and 0.656 eV respectively. Oxide aluminium thin films obtained would be a suitable tool owing to their potential applications in clinical dosimetry, in the dose distributions due to weekly penetrating radiation determination, and in interfaces dosimetry. (Author)

  1. Characterization of OSL dosemeters for application in dose evaluation in computerized tomography procedures; Caracterizacao de dosimetros OSL para aplicacao em avaliacoes de doses em procedimentos de tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Louise M.G.; Santos, Josilene C.; Umisedo, Nancy K.; Terini, RIcardo A.; Costa, Paulo R. [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica

    2016-07-01

    This work aims to present results of the characterization of Al{sub 2}O{sub 3}:C optically stimulated luminescent detector (OSLD). The following aspects were studied: sensitivity, energy response and air kerma dependence in computed tomography (CT) energy range. The main objective of this work is to evaluate the applicability of this kind of dosimeter for CT organ dose assessment. The energy response showed a non-homogenous pattern which has already been found in literature. The air kerma dependence of OSL signal showed a linear trend. Concerning their sensitivity, it was observed that the same batch can have different responses for the same quality, after a second irradiation step, which shows that this kind of detector should be used with care in case of more than one irradiation. (author)

  2. Radiation condition in computerized tomography (CT): determination and calibration of dosemeters; Condicoes de radiacao em tomografia computadorizada (TC): determinacao e calibracao de dosimetros

    Energy Technology Data Exchange (ETDEWEB)

    Adrade, L.C.; Peixoto, J.G.P., E-mail: lucio-andrade@hotmail.com [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2016-07-01

    RQT is the standard for radiation conditions in computed tomography . It simulates a beam unrelieved of a CT scanner . The camera pencil ionization dosimeter is used in CT. The LNMRI become known characterization of RQT radiation conditions and the secondary standard calibration for type pencil ionisation chambers in its lab. The obtained beam has the characteristics required by IEC 61267. The results of the calibration presented combined uncertainty expanded to 95.45% from 2.22% . (author)

  3. CW-OSL measurement protocols using optical fibre Al2O3:C dosemeters

    DEFF Research Database (Denmark)

    Edmund, J.M.; Andersen, C.E.; Marckmann, C.J.

    2006-01-01

    A new system for in vivo dosimetry during radiotherapy has been introduced. Luminescence signals from a small crystal of carbon-doped aluminium oxide (Al2O3:C) are transmitted through an optical fibre cable to an instrument that contains optical filters, a photomultiplier tube and a green (532 nm...

  4. Characteristic parameters analysis on diagnostic X-ray beams for dosemeter calibration; Analise de parametros caracteristicos de feixes de raios-X diagnostico para calibracao de dosimetros

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Paulo Marcio Campos de

    2008-07-01

    Ionizing radiation metrology is the base to achieve reliable dose measurements in ali areas; it is also part of the framework that is established to assure radiation protection procedures in order to avoid or minimize the harmful biological effect that may be caused by ionizing radiation. A well done metrology means the use of reliable instruments that comply with standard performance requirements worldwide accepted. Those instruments are expected to be calibrated by Metrology Laboratories under well defined conditions. The International Electrotechnical Commission (IEC) in Standard 61267 established the reference radiations for medical diagnostic x-ray equipment that are recommended to be used for calibrating dosimetric systems for diagnostic dosimetry. In this work, X-ray beam qualities were established in a Calibration Laboratory and their characteristics were analyzed through the measurement of beam parameters like inherent tube filtration, beam uniformity and field size, energy spectra and peak voltage for additional filtration with 94.425 por cent and 99.999 por cent purity filters. Also, the first half-value layer and the homogeneity coefficient were measured for the three RQR 2, RQR 6 and RQR 10 IEC beam qualities and they were analyzed according to the IEC standard. Air-kerma measurements were carried out with an ionization chamber that had its reliability confirmed through repetition and reproducibility reading tests. In 50 sets of measurements the maximum standard deviation found of 10 successive readings was 0.19 %; the maximum shift of the reading mean value at a fixed geometry condition was 0.80 % with an overall standard deviation of 0.23 %. Results showed that the use of different purity filters did not cause a relevant influence on the beam energy spectra. An ionization chamber was also calibrated against a standard dosimeter in ali implemented reference radiations and the relevant sources of uncertainties were estimated. Calibration could be done with an expanded uncertainty of 1.50% for a coverage factor of 2 at a 95.45 % confidence level, mainly due to the uncertainty of 0.58% caused by the positioning set-up of the ionization chamber. (author)

  5. Commercial sugar, an alternative dosemeter for the dose determination in radiological emergency conditions; Azucar comercial, un dosimetro alternativo para la determinacion de dosis en situaciones de emergencia radiologica

    Energy Technology Data Exchange (ETDEWEB)

    Urena N, F.; Galindo, S. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    It was carried out the dosimetric evaluation of commercial sugar, with the purpose to determine the feasibility to be able to use this type of substance as a dosimetric material in cases to present some radiological emergency cases. The studied parameters using the Electron Paramagnetic Resonance (EPR) technique were: pre-doses signal or depth signal, dose-response stability, reproducibility, reliability and signal clearing decreasing. (Author)

  6. An On-Board TLD System for Dose Monitoring on the International Space Station

    Energy Technology Data Exchange (ETDEWEB)

    Apathy, I.; Deme, S.; Bodnar, L.; Csoeke, A.; Hejja, I

    1999-07-01

    This institute has developed and manufactured a series of thermoluminescence dosemeter (TLD) systems for spacecraft, consisting of a set of bulb dosemeters and a small, compact TLD reader suitable for on-board evaluation of the dosemeters. By means of such a system highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations as well as on the Space Shuttle. A new implementation of the system will be placed on several segments of the ISS as the contribution of Hungary to this international enterprise. The well proven CaSO{sub 4}:Dy dosemeters will be used for routine dosimetry of the astronauts and in biological experiments. The mean LET value will be measured by LiF dosemeters while doses caused by neutrons are planned to be determined by {sup 6}LiF/{sup 7}LiF dosemeter pairs and moderators. A detailed description of the system is given. (author)

  7. Instrumentation for the individual dosimetry of workers

    CERN Document Server

    Thévenin, J C

    2003-01-01

    The control of the radiation dose exposure of workers and personnel exposed to ionizing radiations (nuclear industry, nuclear medicine, army, university laboratories etc..) is ensured by individual dosemeters. This dosimetry is mandatory for all workers susceptible to be exposed to more than 30% of the regulatory dose limit. dosemeters are worn on the chest and in some particular cases, on the finger (dosemeter rings) or on the wrist. Passive dosemeters allow to measure the dose a posteriori, while electronic dosemeters allow a direct reading and recording of the dose. This article presents successively: 1 - the general principles of individual dosimetry: situations of exposure, radiation detection, operational data, standardization, calibration and quality assurance, measurement uncertainties; 2 - goals and regulatory framework of individual dosimetry: regulation and recommendations, optimization, respect of dose limits, accidental situations; 3 - passive dosemeters: film, thermoluminescent, radio-photolumin...

  8. Influence of ultraviolet radiation (UV) on the physicochemical stability of a radon dosemeter: the CN-85; Influence du rayonnement ultraviolet (UV) sur la stabilite physico-chimique d'un dosimetre du radon: le CN-85

    Energy Technology Data Exchange (ETDEWEB)

    Mbodj, M.; Sow, H.T.; Ndoye, O.; Gassama, S.S. [Faculte de Medecine, UCAD, Lab. de Biophysique et Medecine Nucleaire (Senegal); Ndiaye, A.; Diarra, M. [Faculte de Medecine, UCAD, Lab. de Biophysique pharmaceutique (Senegal); Ndiaye, D.; Tidjani, A. [Faculte des Sciences et Techniques, UCAD, Lab. des Rayonnements Naturels et Artificiels (Senegal)

    2007-07-15

    The radon dosimeters such as cellulose nitrates are often degraded under the action of certain physical or chemical factors. In our research we studied the behavior of the CN-85, solid state nuclear track detector, in very sunny tropical atmosphere (natural photo-ageing) and in enclosure S.E.P.A.P. 12/24 (artificial accelerated photo-ageing), before its exposure to a source of particles alpha (Am-241). The results showed chemical modifications of the detector, involving a change of coloring in accelerated as well as in natural photo-ageing, yet more in the first mode. The comparative study of the two modes (of photo-ageing) made it possible to determine an ageing acceleration factor of 2.5. The irradiation of the detectors with the particles alpha has shown a 98% loss of effectiveness after 40 hours of solar exposure, which makes it possible to consider the operational limit duration of the detector as hardly exceeding a week, in tropical atmosphere. This utilization period could be prolonged inside the dwellings due to the fall of the temperature and luminosity. (authors)

  9. Dose rate range extension of the calibration of dosemeters at LNMRI, Rio de Janeiro, Brazil; Expansao da faixa de taxas de dose para a calibracao de instrumentos de medir radiacao no LNMRI, Rio de Janeiro, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, T.S.; Carlos, M.T.; Ramos, M.M.O., E-mail: tschirn@ird.gov.b, E-mail: marcia@ird.gov.b, E-mail: mmoramos@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The present work has an objective the implantation of a experimental arrange for application of essays of instrument calibration for measurement of low dose rate, which measure rate less than 10 {mu}Sv/h

  10. Development of a compact electronic dosemeter from CMOS sensor for radon measurement; Developpement d'un dosimetre electronique compact a base de capteurs CMOS pour la mesure du radon

    Energy Technology Data Exchange (ETDEWEB)

    Higueret, St

    2007-12-15

    Radon detection is a long-standing challenge in the field of radioprotection, and the IPHC Institute of Strasbourg has pushed for the development of a fully electronic device, portable and really standalone. Our first prototype of CMOS system-on-chip is presented, together with efficiency tests and the corresponding physics simulations (TRIM, GEANT IV). We describe several electronic boards which have been developed for various kinds of tests, firstly passive detection of {alpha}-particles from gaseous {sup 222}Rn in a large spectrum of activity concentrations. In a second stage, active collection of the daughter isotopes {sup 218}Po and {sup 214}Po was performed: these elements, appearing as attached on the aerosols present in air, are an important contribution to internal {alpha}-irradiation. The final electronic system, of only 10 cm size, includes four independent chips to ensure simultaneous detection of radon gas and its aerosols. An excellent linearity has been measured up to 80 kBq.m{sup -3} on the BACCARA bench of the IRSN at Saclay. A new generation chip is also studied. (author)

  11. PPV analysis and tension of spectral peak in an X radiation equipment for dosemeter calibration; Analise do PPV e tensao de pico espectral em um equipamento de raios-X para calibracao de dosimetros

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, P.M.C.; Santana, P.C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem; Lacerda, M.A.S.; Silva, T.A. da, E-mail: pmco@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2014-07-01

    Dosimetry laboratories around the world try to achieve metrology consistency between the X-rays beams for therapy and diagnostic detectors calibration. One of the parameters to characterize X-ray beam is the practical peak voltage (PPV) assessment. In this work were evaluated the PPV and spectral peak voltage in the potential constant X-ray equipment, that result in a mean difference of 1.4 %. (author)

  12. Study of the response to neutrons of a personal dosemeter in mixed fields (n, {gamma}) in function of Hp(10); Estudio de la respuesta a neutrones de un dosimetro personal en campos mixtos (n, {gamma}) en funcion de Hp(10)

    Energy Technology Data Exchange (ETDEWEB)

    Cruzate, J.; Gregori, B.; Carelli, J.; Aguerre, L.; Discacciatti, A. [Autoridad REgulatoria Nuclear, Av. del Libertador 8250 (1429), Buenos Aires (Argentina)]. e-mail: cruzate@cae.arn.gov.ar

    2006-07-01

    In this work it is presented the theoretical study and their experimental validation of the answer of the personal dosimetro in terms of the component of neutrons of the personal equivalent dose Hpn(10) in function of the energy, in presence of fields of neutrons and range. The personal dosimetro, based on detecting termoluminiscentes (TLD), it consists of two detectors 7LiF and two 6LiF, located low filters of plastic and cadmium starting from whose information is evaluated the component range and of neutrons of the dose. Additionally it consists of a detecting CaF2, used basically to discriminate against the energy of the component range and to make the corresponding corrections on the evaluation of the dose range obtained with the 7LiF. The answer to neutrons in function of the energy, defined as the quotient among the one I number of reactions 6Li(n, a)4He taken place in each TLD and the Hpn(10), it was calculated using the code MCNPX and the library ENDF/B-VI. You model the dosimetro under the irradiation conditions proposed by the ISO8529-3. Faces monoenergeticos were simulated in the range of energy understood between 70 keV and 5 MeV. The dispersion in each one of the results of the simulation is smaller than 3%. You I study the existent relationship among the answer te6rica, reactions (n,a)/Hpn(10) and the experimental one, nC/Hpn(10), for a given thermal treatment. The factor of resulting conversion is constant in the energy and similar to 1,71 104 reacciones(n, a)/nC, with a smaller standard deviation to 10%. The experimental answer was obtained starting from the irradiations carried out in the mark of the International Intercomparacion of Dosimetria in Mixed Campos (n,) 2004 organized by the OIEA next to the PTB (Germany) and the IRSN (France). The extension of these calculations to other spectra of neutrons of fields real they will allow to obtain group of factors of application conversion in routine and accidental situations. (Author)

  13. Diffusion simulation of ferric ions in dosemeter Fricke-gel with variable diffusion coefficient; Simulacao da difusao de ions ferricos em dosimetros Fricke-gel com coeficiente de difusao variavel

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Caio Jacob; Bevilacqua, Joyce da Silva, E-mail: caio.milani@usp.br, E-mail: joyce@ime.usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. de Matematica e Estatistica. Dept. de Matematica Aplicada; Rodrigues Junior, Orlando, E-mail: rodrijr@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes

    2014-07-01

    Dosimetry using dosimeters Fricke-xylenol-Gel (FXG) allows confirmation and better understanding of radiotherapy treatments. The technique involves the evaluation of volumes irradiated by magnetic resonance imaging (MRI) or CT-optical. In both cases, the time spent between the irradiation and measurement is an important factor that directly influences the results. The quality of the images can be compromised by the mobility of ferric ions (Fe 3+), formed during the interaction of radiation with matter, increasing the uncertainty in determining the isodose. In this work, we simulated the dynamic involving ferric ions formed in one irradiated region irradiated in a two-dimensional domain with a variable diffusion coefficient. This phenomenon is modeled by a differential equation and solved numerically by an efficient algorithm that generalizes the Crank-Nicolson method. The stability and consistency of the method guarantee the convergence of the numerical solution for a predefined tolerance based in the choice of discretization steps of time and space. Different continuous functions were chosen to represent the diffusion coefficient and graphical views of the phenomenon are presented for a better understanding of the process.

  14. Simulation of ferric ions transfer in dosemeter Fricke-Xylenol-Gel in means no homogeneous; Simulacao da difusao de ions ferricos em dosimetros Fricke-Xilenol-Gel em meios nao homogeneos

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Caio J.; Bevilacqua, Joyce da Silva, E-mail: caio.milani@usp.br, E-mail: joyce@ime.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Matematica e Estatistica. Departamento de Matematica Aplicada; Cavinato, Christianne C.; Rodrigues Junior, Orlando; Campos, Leticia L., E-mail: rodrijr@ipen.br, E-mail: Icrodri@ipen.br, E-mail: ccavinato@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (lPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes

    2013-11-01

    Dosimetry in three dimensions using Fricke-Xilenol-Gel dosimeters (FXG) allows the confirmation and a better understanding of a treatment by Radiotherapy. The technique involves the assessment of the irradiated volumes by magnetic resonance imaging (MRI) or optical-CT. On both cases, the time elapsed between the irradiation and the measurement is an important factor in the quality of results. The quality of the images can be compromised by the mobility of the ferric ions (Fe{sup 3+}), formed during the the interaction of the radiation with the matter, increasing the uncertainty in the determination of the isodoses in the volume. In this work, the phenomenon of the diffusion of the ferric ions formed by an irradiated region is simulated in a bidimensional domain. The dynamic of the Fe{sup 3+} in Fricke-Gel is modeled by a parabolic partial differential equation and solved by the ADI-Peaceman-Rachford algorithm. Stability and consistency of the method guarantee the convergence of the numerical solution for a pre-defined error magnitude, based on choices for the discretization values of time and space. Homogeneous and non-homogeneous cases are presented considering an irradiated region and a physical barrier that prevents the movement of the ions, on the non-homogeneous case. Graphical visualizations of the phenomenon are presented for better understanding of the process. (author)

  15. Characterization of Al{sub 2}O{sub 3}:C dosemeters for photon dosimetry using OSL technique; Caracterizacao de dosimetros de Al{sub 2}O{sub 3}:C para dosimetria de fotons utilizando a tecnica OSL

    Energy Technology Data Exchange (ETDEWEB)

    Villani, D.; Almeida, S.B.; Campos, L.L., E-mail: dvillani@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2016-07-01

    The optically stimulated dosimetry (OSL) has gained prominence in clinical and academic applications in Brazil. In this paper, we present results of the characterization OSL dosimeters Al{sub 2}O{sub 3}:C (TLD-500) manufactured by Rexon™ Components and TLD Systems in a RISØ reader, model TL/OSL-DA-20 for dosimetry of high-energy photon beams. All reader parameters, and its variations were evaluated. (author)

  16. Implementation of a laboratory for manufacture, repair and electric calibration of dosemeters based in ionization chambers utilized in radiotherapy; Implementacao de um laboratorio para manutencao, reparo e calibracao eletrica de dosimetros baseados em camaras de ionizacao, utilizados em radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Becker, P.H.B.; Peres, M.A.L.; Moreira, A.J.C.; Nette, H.P. [Instituto de Radioprotecao e Dosimetria. Av. Salvador Allende S/N. Barra de Tijuca CEP: 22780-160. Caixa Postal: 37750 Rio de Janeiro-RJ (Brazil)

    1998-12-31

    Manufacturers of ionization chamber dosimeters for radiotherapy maintain only sales representatives in Brazil with no servicing capability causing difficulties to customers/users to get broken equipment back into operation. Aiming to partially solve this problem, a laboratory for maintenance, repair and electrical calibration was started in 1995 with the support of a two year IAEA Technical Assistance Project (BRA/1/031). (Author)

  17. Personnel photon dosimeter on the base of TLD sup n sup a sup t LiF

    CERN Document Server

    Kaskanov, G Y

    2003-01-01

    A personnel photon dosemeter on the basis of thermoluminescence detectors (TLD) sup n sup a sup t LiF is described. Experimental responses of the dosemeters in the unit of individual equivalent dose H sub p (10) for energy of photons 59.5, 120, 662, and 1250 keV are presented. It is shown that the dosemeter allows one to measure H sub p (10) with admissible uncertainty in the energy range from 60 to 1250 keV.

  18. Review of personal monitoring techniques for the measurement of absorbed dose from external beta and low energy photon radiation

    DEFF Research Database (Denmark)

    Christensen, Poul

    1986-01-01

    The techniques available at present for personal monitoring of doses from external beta and low energy photon radiation are reviewed. The performance of currently used dosimetry systems is compared with that recommended internationally, and developments for improving the actual performance...... are outlined. The subjects dealt with compromise: the quantity to be measured, the required accuracy of measurement, calibration procedures, and dosemeter design including the main parameters influencing the energy and angular response of the dosemeter, such as detector thickness, filter thickness, dosemeter...

  19. Optically stimulated luminescence response to Al2O3 to beta radiation

    DEFF Research Database (Denmark)

    Akselrod, A.; Akselrod, M.S.; Agersnap Larsen, N.

    1999-01-01

    High sensitivity dosemeters based on Al2O3:C have been prepared and tested for use as beta dosemeters using optically stimulated luminescence (OSL). Two types of sample were prepared and tested, namely unpolished thick, single crystal chips and thin powder layers on aluminium substrates. The samp......High sensitivity dosemeters based on Al2O3:C have been prepared and tested for use as beta dosemeters using optically stimulated luminescence (OSL). Two types of sample were prepared and tested, namely unpolished thick, single crystal chips and thin powder layers on aluminium substrates...

  20. Development in neutron dosimetry: automatic traces reading system and albedo OSL dosimetry; Developpement en dosimetrie neutron: systeme automatique de lecture de traces et dosimetrie albedo OSL

    Energy Technology Data Exchange (ETDEWEB)

    Million, M.; Perks, C.A.; Faugoin, S.; Archambault, V. [LCIE Landauer, 92 - Fontenay aux Roses (France)

    2009-07-01

    To answer to a regulatory evolution and technical constraints, the Landauer group introduced on the make an automatic reading system of neutron traces and an albedo dosemeter based on the O.S.L. in light dosemeters (O.S.L. for optically stimulated luminescence). In this article are described the last developments in matter of neutron dosimetry. (N.C.)

  1. Dosimeter configurations for the measurement of Hs(0.07) and Hp(10) from photons

    DEFF Research Database (Denmark)

    Christensen, P.; Bøtter-Jensen, L.; Ennow, K.

    1990-01-01

    The optimisation is discussed of filter/detector configurations of dosemeters for individual monitoring for photons in the energy range from 20 keV to 1.3 MeV. Experimental data are given on energy and angular responses of dosemeters with different combinations of aluminium and plastic filters. Li...

  2. Albedo Neutron Dosimetry in a Deep Geological Disposal Repository for High-Level Nuclear Waste.

    Science.gov (United States)

    Pang, Bo; Becker, Frank

    2017-04-28

    Albedo neutron dosemeter is the German official personal neutron dosemeter in mixed radiation fields where neutrons contribute to personal dose. In deep geological repositories for high-level nuclear waste, where neutrons can dominate the radiation field, it is of interest to investigate the performance of albedo neutron dosemeter in such facilities. In this study, the deep geological repository is represented by a shielding cask loaded with spent nuclear fuel placed inside a rock salt emplacement drift. Due to the backscattering of neutrons in the drift, issues concerning calibration of the dosemeter arise. Field-specific calibration of the albedo neutron dosemeter was hence performed with Monte Carlo simulations. In order to assess the applicability of the albedo neutron dosemeter in a deep geological repository over a long time scale, spent nuclear fuel with different ages of 50, 100 and 500 years were investigated. It was found out, that the neutron radiation field in a deep geological repository can be assigned to the application area 'N1' of the albedo neutron dosemeter, which is typical in reactors and accelerators with heavy shielding. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Low temperature dosimetry in LiF: Mg, Cu, P and CaSO{sub 4}: Dy doped crystals; Dosimetria de baja temperatura en cristales dopados LiF: Mg, Cu, P y CaSO{sub 4}: Dy

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Z, E.; Ramos B, S.; Negron M, A.; Rivera, T. [Instituto de Ciencias Nucleares, UNAM, A.P. 70-543, 04510 Mexico D.F. (Mexico)

    2000-07-01

    It is presented a behavior study of LiF solid dosemeters doped with Mg, Cu and P also polycrystalline samples of CaSO{sub 4} with Dy sinterized in laboratory, both of them were subjected at low temperature. In order to analyse linear behavior to the dose of these dosemeters, it was used thermoluminescence. These materials were exposed to gamma radiation coming from a Co-60 source. The samples were irradiated at dose rates 1.08 {+-} 0.01 Gy/min at liquid nitrogen temperature (LNT) and also the response of dosemeters are compared at ambient temperature and LNT. (Author)

  4. Performance test of dosimetric services in the EU member states and Switzerland for the routine assessment of individual doses (photon, beta and neutron)

    DEFF Research Database (Denmark)

    Bordy, J.M.; Stadtmann, H.; Ambrosi, P.

    2000-01-01

    The results are given of a consolidated performance test for whole-body, and extremity personal dosemeters broadly representative of those in use in the EU member states and Switzerland. Beta, photon and neutron personal dosemeters were used to assess the routine services ability to determine...... and report personal dose equivalents. In total, 69 sets of dosemeters were entered in the test by 34 services. About 1000 dosemeters were irradiated. One purpose of the consolidated performance test and the analysis of the results was to enable the assessment of criteria for the acceptability...... of the dosimetry of routine services. It was assumed that each service would have already done a type test before performing routine dosimetry: the radiation fields were chosen to simulate, as far as possible, workplace radiation fields by mixing combining energies and incident angles. The results of photon...

  5. Study of the leakage current of clinical dosimeters for teletherapy; Estudo da corrente de fuga de dosimetros clinicos para teleterapia

    Energy Technology Data Exchange (ETDEWEB)

    Damatto, Willian B.; Santos, Gelson P.; Potiens, Maria da Penha A.; Caldas, Linda V.E.; Vivolo, Vitor, E-mail: wbdamatto@ipen.b, E-mail: gpsantos@ipen.b, E-mail: mppalbu@ipen.b, E-mail: lcaldas@ipen.b, E-mail: vivolo@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    This work demonstrates the importance of quality control of clinical dosemeters and therefore the equipment for radiotherapy treatment, exhibiting the necessary care related to answers and sensibilities and the possible defects of the clinical assembly

  6. Harmonisation and dosimetric quality assurance in individual monitoring for external radiation

    DEFF Research Database (Denmark)

    Bartlett, D.T.; Ambrosi, P.; Back, C.

    2001-01-01

    The current situation amongst Member States is that there are widely differing national requirements for dosimetric services and for dosemeter performance. It is clear that with the free movement of workers within the European Union (EU) and the requirements for individual dosimetry given...... of individual monitoring using personal dosemeters and assisting movement towards harmonised procedures. An outline of the work of the action group is given and the term 'harmonisation' is discussed....

  7. Coincidence in the dose estimation in a OEP by different methods; Coincidencia en la estimacion de dosis en un POE por diferentes metodos

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Arceo M, C.; Brena V, M. [ININ, Km. 36.5, Carretera Mexico-Toluca, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: cgc@nuclear.inin.mx

    2007-07-01

    The case of an apparent overexposure to radiation according to that indicated for the thermoluminescent dosemeter 81.59 mSv (TLD) of a occupationally exposed hard-working (POE), for that was practiced the study of biological dosimetry. The estimated dose was 0.12 Gy with which was proven the marked dose registration by the TLD dosemeter. It was concluded that both doses are the same ones. (Author)

  8. Tl response of LiF:Mg, Cu, P + PTFE to Am-Be neutrons; Respuesta Tl de LiF: Mg, Cu, P + PTFE a neutrones de Am-Be

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, P.R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    In different laboratories of the world it is followed the research about development of new Tl materials, whose main characteristics should be their equivalence with the tissue and their high sensibility to any type of radiation. The study consists in to measure the Tl peak intensity which TLD-100 presents at being irradiated with neutrons and that appears over 250 Centigrade, for compare it with the Tl intensity of the LiF: Mg, Cu, P + PTFE dosemeters. However, not all dosemeters of the same group show the interesting peak, by this only can be the total Tl intensity of dosemeters studied. In the ININ dosemeters development laboratory, we have developed a Tl material of lithium fluoride activated with magnesium, copper and phosphorus (LiF: Mg, Cu, P) that in polycrystalline powder form is almost 35 times more sensitive than the TLD-100 commercial dosemeter of Harshaw/Filtrol, USA. With the use of polytetrafluorethylene (PTFE) and with the above described Tl material, it has been possible to obtain dosemeters in pellet form of LiF: Mg, Cu, P + PTFE. (Author)

  9. The Conditions of use of traditional heating vs fast heating readers of thermoluminescent dosemeters, a comparison. Les conditions d'utilisation d'un lecteur de dosimetres TL a chauffage traditionnel et d'un lecteur automatique a chauffage rapide. Leur comparaison

    Energy Technology Data Exchange (ETDEWEB)

    Marinello, G.; Pollack, J. (Hopital Henri Mondor, 94 - Creteil (FR)); Blanchard, P.; Barthe, J. (CEA Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (FR). Dept. de Protection Technique)

    1990-01-01

    The dosimetric properties of lithium borate activated with manganese or copper have been compared according to the heating procedures, i.e. with either a traditional heating reader or a new fast heating device associated with an automatic reader. When the adjustments of preheating and main heating are made optimal, fading becomes independent of the reader used and the reproducibility of the measurements is very good. The response curve of the TL material vs the dose is also found to be independent of the reader, provided it is normalized to 1 for the same reference dose. On the other hand the variation of the response vs energy (photon or electron beams) depends upon the heating procedures. Finally a particular characteristic of Li{sub 2}B{sub 4}O{sub 7}: Cu has been demonstrated: the response corresponding to a given dose is not proportional to the mass of the TL material used for the reading. As an interesting consequence it is possible to avoid weighing each reading sample and therefore to save time.

  10. Measuring the absorbed dose in critical organs during low rate dose brachytherapy with {sup 137} Cs using thermoluminescent dosemeters; Medicion de la dosis absorbida en organos criticos durante braquiterapia de baja tasa de dosis con {sup 137} Cs usando dosimetros termoluminiscentes

    Energy Technology Data Exchange (ETDEWEB)

    Torres, A. [UAEM, Fac. de Medicina, 50180 Toluca, Estado de Mexico (Mexico); Gonzalez, P.R. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Furetta, C.; Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico); Andres, U.; Mendez, G. [Centro Estatal de Cancerologia de Tabasco, A. Gregorio Mendez No. 2838, Col. Atasta, 86100 Villahermosa, Tabasco (Mexico)

    2003-07-01

    Intracavitary Brachytherapy is one of the most used methods for the treatment of the cervical-uterine cancer. This treatment consists in the insertion of low rate dose {sup 137}Cs sources into the patient. The most used system for the treatment dose planning is that of Manchester. This planning is based on sources, which are considered fixed during the treatment. However, the experience has shown that, during the treatment, the sources could be displaced from its initial position, changing the dose from that previously prescribed. For this reason, it is necessary to make measurements of the absorbed dose to the surrounding organs (mainly bladder and rectum). This paper presents the results of measuring the absorbed dose using home-made LiF: Mg, Cu, P + Ptfe thermoluminescent dosimeters (TLD). Measurements were carried out in-vivo during 20 minutes at the beginning and at the end of the treatments. Results showed that the absorbed dose to the critical organs vary significantly due to the movement of the patient during the treatment. (Author)

  11. SOS chromotest: an indicator of damage induced to DNA by radiations, for use as a biological effect dosemeter. Le SOS chromotest: un indicateur de l'endommagement de l'ADN par les rayonnements candidat pour une utilisation comme dosimetre d'effet

    Energy Technology Data Exchange (ETDEWEB)

    Laugier, J. (Etablissement Technique Central de l' Armement (ETCA), 94 - Arcueil (France))

    1994-01-01

    The biologically relevant results of the interactions of ionizing radiations in the living medium are many shorts of alterations impairing the functional integrity of the cellular macromolecules of genetical interest. It is well known that almost all the subsequent biological effects, whatever their level of integration in a complex organism, originate from these lesions. The physical dosimetry, which is based on energy deposits only, intrinsically leaves the inducing potency of radiations out of account. This makes it pertinent to score, even indirectly, the damages to the genetical stock, giving rise to a more predictive method, which happens to be goal of the so-called genotoxicity tests. The Institute Pasteur's SOS Chromotest is one of them. The first results have been satisfactory to forward the program aimed at qualifying the test as an ''effect dosimeter''. (author). 9 refs., 9 figs., 1 tab.

  12. Quality control for thermoluminescent dosemeters TLD-100 de Li F: Mg, Ti for high dose rate treatments using Ir-192 sources in breast, esophagus and bronchus; Control de calidad con dosimetros thermoluminiscentes TLD-100 de Li F: Mg, Ti para tratamientos de alta tasa de dosis com fuentes de Ir-192 en canceres de seno, esofago y bronchio

    Energy Technology Data Exchange (ETDEWEB)

    Torres, F. [Universidad Nacional de Colombia, Bogota (Colombia)]. E-mail: franciscotorreshoyos@yahoo.com; Plazas, M.C. [Instituto Nacional de Cancerologia, Bogota (Colombia); Cavadia, W. [Universidad de Cordoba (Colombia)

    2004-07-01

    Rods - shaped, TLD - 100, LiF: Mg,Ti thermoluminescence dosimeters are used to check duality control during breast, esophagus and bronchus cancer treatments with high rate dose and Ir -192 source. We conclude that the specificity dose in prescription points is in agreement with parameters given in international protocols. (author)

  13. Proposal of a postal system for Ir-192 sources calibration used in high dose rate brachytherapy with LiF:Mn:Ti thermoluminescent dosemeters; Proposta de um sistema postal para a calibracao de fontes de {sup 192} Ir, utilizadas em braquiterapia de alta taxa de dose, com dosimetros termoluminescentes de LiF: Mn: Ti

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, W.S.; Borges, J.C.; Almeida, C.E.V. [Instituto de Radioprotecao e Dosimetria. CNEN Caixa Postal 37750, 22780-160, Rio de Janeiro (Brazil)

    1998-12-31

    A proposal in order to improve the brachytherapy quality control and to allow postal intercomparison of Ir-192 sources used in high dose rate brachytherapy has been presented. The LiF: Mn: Ti (TLD 100) detector has been selected for such purpose. The experimental array and the TLDs irradiation and calibration techniques, at the treatment units, have been specified in the light of more recent methodology of Ir-192 calibration sources. (Author)

  14. Dosimetric evaluation of the response of the TLD-100 dosemeters in the IMRT technique by 'Step and Shoot'; Evaluacion dosimetrica de la respuesta de los dosimetros TLD-100 en la tecnica de IMRT por 'Step and Shoot'

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez, J. [Fundacion Clinica Valle del Lili, A.A. 020338, Cali (Colombia); Benavides, S.O. [Depto. de Fisica, Universidad del Valle, A.A. 25360, Cali (Colombia)

    2005-07-01

    We show the results of the dosimetry response of LiF thermoluminescent crystals: TLD-100, where they were radiated in a linear accelerator Siemens Primus Hl using the Intensity Modulated Radiation Therapy (IMRT) by step and shoot technique. Previous to the crystals calibration and response evaluation, the acceptation procedures recommended by the TG-53 protocol for validation of the technique were carried out. The planning system utilized was the Theraplan Plus 3.8, using the algorithm of Pencil Kernel. The register and verification system was Lantis 5.2. The response curve of dose versus charge was obtained from the readings of the TLD in a Harshaw 3500. The crystals were radiated in a Bench- Marck phantom with doses previously determined by using ionization chambers for square radiation fields, in a beam with a 0.68 TPR20,10 corresponding to 6 MV of energy. We compare the response of these through of radiation of segmented fields in a Anthropomorphic phantom and the calculated doses by the planning system. The results obtained in the crystals response show deviations less than 5 % between the measured dose and the calculated dose in the zones of low gradient. It allows its implementation like routine control of quality by IMRT. (Author)

  15. Production of thermoluminescent dosemeters based on MgB{sub 4}O{sub 7}: Dy and MgB{sub 4}O{sub 7}: Tm; Producao de dosimetros termoluminescentes a base de MgB{sub 4}O{sub 7}: Dy e MgB{sub 4}O{sub 7}: Tm

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Luiza Freire de; Souza, Divanizia N., E-mail: luizaf25@hotmail.com, E-mail: divanizi@ufs.br [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Programa de Pos-Graduacao em Fisica

    2013-07-01

    The thermoluminescent dosimetry (TL) is a well-established technique for the detection of ionizing radiation in hospitals, clinics, and industrial establishments where there is the need to quantify the radiation. For this practice is require the use phosphors which are sensitive to radiation. Some phosphors are already commonly used in this practice, for example, TLD-100 (LiF: Mg, Ti), CaSO{sub 4}:Tm and CaSO{sub 4}:Dy. A compound that was most recently introduced in dosimetry and has many advantageous features to detect neutrons, electrons and gamma is the magnesium tetraborate (MgB{sub 4}O{sub 7}), but the undoped material is not good for dosimetry, since signal does not show satisfactory thermoluminescence. The present work presents the analysis of the compound MgB{sub 4}O{sub 7} when doped with rare earth elements, thulium (Tm) and dysprosium (Dy). The production of MgB{sub 4}O{sub 7}: Dy and MgB{sub 4}O{sub 7}: Tm occurred under acidic conditions. Following the process of crystal growth, several tests were made on phosphors produced to verify the quality of materials as TL dosimeter. Initially, was made the identification of the crystalline phases found in the material, using the technique of X-ray diffractometry, and then were evaluated and compared the TL emission curves of the crystals with two different types of dopants, to this, the samples were irradiated with different radiation sources: {sup 137}Cs (0,66 MeV), {sup 60}Co (1.25 MeV) and X-rays (0.41 MeV) and based on the results was evaluated the energy dependence of phosphors. Another characteristic analyzed, was the decay of TL signal for the material (fading). The results show that the material can be an excellent TL dosimeter when doped with rare earth elements Dy and Tm. (author)

  16. The emission of atoms and molecules accompanying fracture of single-crystal MgO

    Science.gov (United States)

    Dickinson, J. T.; Jensen, L. C.; Mckay, M. R.; Freund, F.

    1986-01-01

    The emission of particles due to deformation and fracture of materials has been investigated. The emission of electrons (exoelectron emission), ions, neutral species, photons (triboluminescence), as well as long wavelength electromagnetic radiation was observed; collectively these emissions are referred to as fractoemission. This paper describes measurements of the neutral emission accompanying the fracture of single-crystal MgO. Masses detected are tentatively assigned to the emission of H2, CH4, H2O, CO, O2, CO2, and atomic Mg. Other hydrocarbons are also observed. The time dependencies of some of these emissions relative to fracture are presented for two different loading conditions.

  17. Dosimetry of Low-Energy Beta Radiation

    DEFF Research Database (Denmark)

    Borg, Jette

    Useful techniques and procedures for derermination of absorbed doses from exposure in a low-energy beta radiation were studied and evaluated. The four techniques included were beta spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical...... low-energy beta radiation field a moderated spectrum from a carbon-14 source was used. The measured responce of a Si(Li) detector to photons (bremsstrahlung) showed fine agreemant with the MC calculated photon response, whereas the difference between measured and MC calculated response to electrons...

  18. The radiation defect accumulation in scintillative crystals of caesium halides under intense electron beam irradiation

    CERN Document Server

    Galiy, P V

    1999-01-01

    The characteristics of defect accumulation and radiolysis at CsI crystals under mean energies of electron irradiation at wide dose rates and ranges of doses have been investigated by such methods: thermostimulated exoelectron emission (TSEE), Auger electron spectroscopy (AES) and optical absorption spectroscopy (OAS). The limit dose rates and absorbed doses of electron irradiation that lead to defects accumulation at room temperature in crystals volume and also surface stoichiometry violation have been evaluated. The doses of electron irradiation that lead to CsI radiolysis, with caesium coagulation in metallic phase have been determined. Some quasi periodic connection of such process with irradiation dose was observed.

  19. Thermoluminescent detectors applied in individual monitoring of radiation workers in Europe--a review based on the EURADOS questionnaire.

    Science.gov (United States)

    Olko, P; Currivan, L; van Dijk, J W E; Lopez, M A; Wernli, C

    2006-01-01

    Among the activities of EURADOS Working Group 2 formed by experts from several European countries is the harmonisation of individual monitoring as part of radiation protection of occupationally exposed persons. Here, we provide information about thermoluminescent detectors (TLDs) applied by the European dosimetric services and the dosimetric characteristics of dosemeters in which these detectors are applied. Among 91 services from 29 countries which responded to the EURADOS questionnaire, 61 apply dosemeters with TLDs for the determination of personal dose equivalent H(p)(10) for photons and beta radiation, and 16 services use TLDs for neutron albedo dosemeters. Those most frequently used are standard lithium fluoride TLDs (mainly TLD-100, TLD-700, Polish MTS-N and MTS-7, Russian DTG-4), high-sensitive lithium fluoride (GR-200, MCP-N) and lithium borate TLDs. Some services use calcium sulphate and calcium fluoride detectors. For neutron dosimetry, most services apply pairs of LiF:Mg,Ti TLDs with (6)Li and (7)Li. The characteristics (energy response) of individual dosemeters are mainly related to the energy response of the detectors and filters applied. The construction of filters in dosemeters applied for measurements of H(p)(10) and their energy response are also reviewed.

  20. Determination of the neutron and photon dose equivalent at work places in nuclear facilities of Sweden. An SSI - EURADOS comparison exercise. Part 2: Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Bartlett, D. [National Radiological Protection Board, Chilton (United Kingdom); Drake, P. [Vattenfall AB, Vaeroebacka (Sweden); Lindborg, L. [Swedish Radiation Protection Inst., Stockholm (Sweden); Klein, H. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Schmitz, Th. [Forschungszentrum Juelich GmbH, Juelich (Germany); Tichy, M

    1999-06-01

    Various mixed neutron-photon fields at workplaces in the containment of pressurised water reactors and in the vicinity of transport containers with spent fuel elements were investigated with spectrometers and dosimeters. The spectral neutron fluences evaluated from measurements with multisphere systems were recommended to be used for the calculation of dosimetric reference values for comparison with the readings of the dosemeters applied simultaneously. It turned out that most of the moderator based area dosemeters overestimated, while the TEPC systems generally underestimated the ambient dose equivalent (DE) values of the rather soft neutron fields encountered at these workplaces. The discrepancies can, however, be explained on the basis of energy dependent responses of the instruments used. The ambient DE values obtained with recently developed area dosemeters based on superheated drop detectors and with track etch based personal dosemeters on phantoms, however, were in satisfying agreement with the reference data. Sets of personal dosemeters simultaneously irradiated on a phantom allowed to roughly estimate the directional dependence of the neutron fluence. Hence, personal and limiting dose equivalent quantities could also be calculated. The personal and ambient DE values were always conservative estimates of the limiting quantities. Unexpectedly, discrepancies were observed for photon DE data measured with GM counters and TEPC systems. The up to 50 % higher readings of the GM counters may be explained by a considerable contribution of high energy photons to the total photon dose equivalent, but photon spectrometry is necessary for final clarification.

  1. Comparison of double dosimetry algorithms for estimating the effective dose in occupational dosimetry of interventional radiology staff.

    Science.gov (United States)

    Järvinen, H; Buls, N; Clerinx, P; Miljanic, S; Nikodemová, D; Ranogajec-Komor, M; Struelens, L; d'Errico, F

    2008-01-01

    'Double dosimetry' i.e. measurement with two dosemeters, one located above the protective apron and one under has been recommended in interventional radiology (IR) to determine the effective dose to staff. Several algorithms have been developed to calculate the effective dose from the readings of the two dosemeters, but there is no international consensus on what is the best algorithm. In this work, a few of the most recently developed algorithms have been tested in typical IR conditions. The effective dose and personnel dosemeter readings were obtained experimentally by using thermoluminescent dosemeters in and on a Rando-Alderson phantom provided with a lead apron. In addition, the effective dose and personnel dosemeter readings were calculated by the Monte Carlo method for the same irradiation geometry. The results suggest that most of the algorithms overestimate effective dose in the selected IR conditions, but there is also a risk of underestimation by using the least conservative algorithms. Two of the algorithms seem to comply best with the chosen criteria of performance, i.e. no underestimation, minimum overestimation and close estimation of effective dose in typical IR conditions. However, it might not be justified to generalise the results. It is recommended that whenever personnel doses approach or exceed the dose limit, IR conditions should be further investigated and the possibility of over- or under-estimation of effective dose by the algorithm used should be considered.

  2. Proton/gamma relative thermoluminescence efficiencies of LiF:Mg,Cu,P+PTFE prepared at ININ and TLD-100H

    Energy Technology Data Exchange (ETDEWEB)

    Avila, O.; Gonzalez, P.; Murillo, G. [Departamento de Fisica, ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)

    2009-10-15

    Properties of LiF:Mg,Cu,P+PTFE dosemeters developed at ININ have been investigated in order to evaluate their performance compared to those of equivalent commercial dosemeters. In this work both LiF:Mg,Cu,P+PTFE and TLD-100H pellets were exposed to low fluence 3 MeV protons and to low dose gamma radiation to evaluate experimental proton/gamma efficiencies. Gamma irradiation was performed using the Vic krad irradiator at ININ at varying doses between 25 and 500 mGy. For proton irradiation the Tandem Van de Graaff accelerator at ININ was used. Dosemeters were placed on a holder inside a scattering chamber where protons impinge on a gold target and scatter in all directions. The holder allows for several angular positions so that dosemeters receive proton fluence between 10{sup 6} and 10{sup 1}0 p/cm{sup 2}. Experimental efficiency values found for LiF:Mg,Cu,P+PTFE and TLD-100H were 0.18 +- 03 and 0.23 +- 0.03, respectively. These results allow to confirm the reliability of the dosemeters developed at ININ. (Author)

  3. Fading of the Tl signal in LiF: Mg, Cu, P during a large post irradiation period; Desvanecimiento de la senal Tl en LiF: Mg, Cu, P durante un largo periodo posradiacion

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, P.R. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico); Furetta, C. [Universidad de Roma, Piazzale Aldo Moro 2, Roma (Italy)

    2004-07-01

    In this work the obtained results of the study of the fading of the Tl signal in dosemeters of LiF activated with magnesium, copper and phosphorus (LiF:Mg,Cu,P) are presented. The studied dosemeters were LiF: Mg,Cu,P + Ptfe, developed in the ININ, taking like reference to the commercial dosemeter GR200A of Chinese manufacture. In both cases the Tl curve presents four peaks; in LiF: Mg,Cu,P + Ptfe, the peaks of smaller size appear in 359 K, 389 K and 447 K, the main dosimetric peak appears in 486 K; in GR200A, the peaks of smaller size appear in 360 K, 389 K and 445 K; while the main dosimetric peak appears in 487 K. The highest fading shown by the dosemeters of LiF: Mg,Cu,P + Ptfe, it was of 3.07%, value very below the one recommended for dosimetric purposes. While the commercial dosemeters presented a fading until of 6.23%, surpassing with the recommended values. The observed fading, it corresponds to the lost of the Tl signal of the peaks 1 and 2, since the first one disappears few hours after the irradiation, while the peak 2, it disappears completely after 94 days, the peak 3 remained stable during the six months of study, while the peak 4, it showed a slight increment due to the contribution of the dose of natural environmental radiation. (Author)

  4. Ionisation Chamber for Measurement of Pulsed Photon Radiation Fields.

    Science.gov (United States)

    Ginzburg, D

    2017-04-28

    The use of pulsed photon radiation in medical, industrial and security sectors has vastly increased during the recent years. The length of pulse from different X-ray flash generators that are commonly used as either portable, battery-operated or fixed systems can be as low as a few femtoseconds. However, the majority of radiation protection instruments, especially various active electronic dosemeters, have limitations when operated in pulsed fields. This study presents measurements that were performed using the dose-integration mode of the RI-02 and Ram Ion survey metres, which are based on ventilated ionisation chamber, when exposed to different pulsed X-ray sources. An intercomparison between the results that were obtained with the survey metres and those that were obtained with thermoluminescence dosemeter, reference passive dosemeter, show good agreement (deviation lies within 10%). © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Quality control for exposure assessment in epidemiological studies

    DEFF Research Database (Denmark)

    Bornkessel, C; Blettner, M; Breckenkamp, J

    2010-01-01

    In the framework of an epidemiological study, dosemeters were used for the assessment of radio frequency electromagnetic field exposure. To check the correct dosemeter's performance in terms of consistency of recorded field values over the entire study period, a quality control strategy...... was developed. In this paper, the concept of quality control and its results is described. From the 20 dosemeters used, 19 were very stable and reproducible, with deviations of a maximum of +/-1 dB compared with their initial state. One device was found to be faulty and its measurement data had to be excluded...... from the analysis. As a result of continuous quality control procedures, the confidence in the measurements obtained during the field work was strengthened significantly....

  6. External doses from radioactive fallout. Dosimetry and levels

    Energy Technology Data Exchange (ETDEWEB)

    Woehni, T.

    1995-12-31

    The design, manufacture and calibration of a TL-based dosemeter for measurement of low level external photon radiation are presented. The dosemeter is based on CaF{sub 2} with 2 mm brass filter for energy compensation. It is able to resolve a 8% dose increase relative to natural background radiation. With this dosemeter external dose measurements were made in 6 villages in a heavily contaminated region in Russia (Chernobyl fallout), in order to assess external doses to the population. The results were analyzed in the light of additional existing information on radioactive deposition, social habits, decontamination measures and other influencing technical and physical factors. The observed dose values were lower than theoretical estimates of external doses based on published values for external dose levels relative to the level of contamination. 84 refs., 7 figs., 5 tabs.

  7. Evaluation of the thermoluminescent detector answers of CaSO{sub 4}:Dy, LiF:Mg,Ti and micro LiF:Mg,Ti in photon clinical beams dosimetry using water simulator; Avaliacao da resposta de detectores termoluminescentes de CaSO4:Dy, LiF:Mg,Ti e microLiF:Mg,Ti na dosimetria de feixes clinicos de fotons utilizando simulador de agua

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, Luciana C.; Veneziani, Glauco R.; Campos, Leticia L., E-mail: lmatsushima@usp.b, E-mail: veneziani@ipen.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (GMR/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes; Sakuraba, Roberto K.; Cruz, Jose C. da, E-mail: rsakuraba@einstein.b, E-mail: jccruz@einstein.b [Sociedade Beneficente Israelita Brasileira, Sao Paulo, SP (Brazil). Hospital Albert Einstein (HAE)

    2011-10-26

    This paper perform the comparative study of thermoluminescent answer of calcium sulfate dosemeter doped with dysprosium (DaSO{sub 4}:Dy) produced by the IPEN, Sao Paulo, with answer of lithium fluoride dosemeters doped with magnesium and titanium (LiF:Mg, Ti) in the dosimetry of clinical beams of photons (6 and 15 MV) by using water simulator object. Dose-answer curves were obtained for gamma radiation of cobalt-60 in the air and in conditions of electronic equilibrium (plate of PMMA), and clinical photons of CLINAC model 2100C accelerators of the two evaluated hospitals: Hospital das Clinicas of the Faculty of Medicine of Sao Paulo university and Hospital Albert Einstein. It was also evaluated the sensitivity and reproduction of the three dosemeters

  8. Development of a reader for track etch detectors based on a commercially available slide scanner

    CERN Document Server

    Steele, J D; Tanner, R J; Bartlett, D T

    1999-01-01

    NRPB has operated a routine neutron personal dosimetry service based on the electrochemical etch of PADC elements since 1986. Since its inception it has used an automated reader based on a video camera and real time analysis. A new and more powerful replacement system has been developed using a commercially available photographic slide scanner. This permits a complete image of the dosemeter to be grabbed in a single scan, generating a 2592x3888 pixel file which is saved for subsequent analysis. This gives an effective pixel size of 10x10 mu m with an image of the entire dosemeter in one field of view. Custom written software subsequently analyses the image to assess the number of etched pits on the dosemeter and read the detector identification number (code). Batch scanning of up to 40 detectors is also possible using an autofeed attachment. The system can be used for electrochemically etched tracks for neutron detectors and chemically etched tracks for radon detectors.

  9. Elaboration of pellets of LiF: Mg, Cu, P and its dosimetric properties; Elaboracion de pastillas de LiF: Mg, Cu, P y sus propiedades dosimetricas

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez C, A.; Gonzalez M, P.R.; Azorin N, J

    1991-03-15

    The LiF: Mg, Cu, P is at the moment in the entire world one of the TL materials of more interest, by its equivalence with the tissue, as well as for its high sensitivity, which is 25 to 35 times greater than of the TLD-100 of Harshaw (USA). In our laboratory dosemeters of this material have been developed in form of sinterized pellets. The importance of these new dosemeters in pellet form is due to that in this form its manipulation is facilitated. Due to its high sensitivity, these dosemeters result to be those but appropriate to measure the ionizing radiations, in intervals of extremely low dose. In this report the method of elaboration of the pellets, as well as its main dosimetric characteristics are presented. (Author)

  10. Microprocessor controlled portable TLD system

    Science.gov (United States)

    Apathy, I.; Deme, S.; Feher, I.

    1996-01-01

    An up-to-date microprocessor controlled thermoluminescence dosemeter (TLD) system for environmental and space dose measurements has been developed. The earlier version of the portable TLD system, Pille, was successfully used on Soviet orbital stations as well as on the US Space Shuttle, and for environmental monitoring. The new portable TLD system, Pille'95, consists of a reader and TL bulb dosemeters, and each dosemeter is provided with an EEPROM chip for automatic identification. The glow curve data are digitised and analysed by the program of the reader. The measured data and the identification number appear on the LED display of the reader. Up to several thousand measured data together with the glow curves can be stored on a removable flash memory card. The whole system is supplied either from built-in rechargeable batteries or from the mains of the space station.

  11. Thermal neutron equivalent dose assessment around the KFUPM neutron source storage area using NTDs. King Fahd University of Petroleum and Minerals.

    Science.gov (United States)

    Abu-Jarad, F; Fazal-ur-Rehman; Al-Haddad, M N; Al-jarallah, M I

    2002-01-01

    Area passive neutron dosemeters based on nuclear track detectors (NTDs) have been used for 13 days to assess accumulated low doses of thermal neutrons around neutron source storage area of the King Fahd University of Petroleum and Minerals (KFUPM). Moreover, the aim of this study is to check the effectiveness of shielding of the storage area. NTDs were mounted with the boron converter on their surface as one compressed unit. The converter is a lithium tetraborate (Li2B4O7) layer for thermal neutron detection via 10B(n,alpha)7Li and 6Li(n,alpha)3H nuclear reactions. The area passive dosemeters were installed on 26 different locations around the source storage area and adjacent rooms. The calibration factor for NTD-based area passive neutron dosemeters was found to be 8.3 alpha tracks x cm(-2) x microSv(-1) using active snoopy neutron dosemeters in the KFUPM neutron irradiation facility. The results show the variation of accumulated dose with locations around the storage area. The range of dose rates varied from as low as 40 nSvx h(-1) up to 11 microSv x h(-1). The study indicates that the area passive neutron dosemeter was able to detect accumulated doses as low as 40 nSv x h(-1), which could not be detected with the available active neutron dosemeters. The results of the study also indicate that an additional shielding is required to bring the dose rates down to background level. The present investigation suggests extending this study to find the contribution of doses from fast neutrons around the neutron source storage area using NTDs through proton recoil. The significance of this passive technique is that it is highly sensitive and does not require any electronics or power supplies, as is the case in active systems.

  12. Thermal neutron equivalent doses assessment around KFUPM neutron source storage area using NTDs

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Jarad, F.; Fazal-ur-Rehman; Al-Haddad, M.N.; Al-Jarrallah, M.I.; Nassar, R

    2002-07-01

    Area passive neutron dosemeters based on nuclear track detectors (NTDs) have been used for 13 days to assess accumulated low doses of thermal neutrons around neutron source storage area of the King Fahd University of Petroleum and Minerals (KFUPM). Moreover, the aim of this study is to check the effectiveness of shielding of the storage area. NTDs were mounted with the boron converter on their surface as one compressed unit. The converter is a lithium tetraborate (Li{sub 2}B{sub 4}O{sub 7}) layer for thermal neutron detection via {sup 10}B(N,{alpha}){sup 7}Li and {sup 6}Li(n,{alpha}){sup 3}H nuclear reactions. The area passive dosemeters were installed on 26 different locations around the source storage area and adjacent rooms. The calibration factor for NTD-based area passive neutron dosemeters was found to be 8.3 alpha tracks.cm{sup -2}.{mu}Sv{sup -1} using active snoopy neutron dosemeters in the KFUPM neutron irradiation facility. The results show the variation of accumulated dose with locations around the storage area. The range of dose rates varied from as low as 40 nSv.h{sup -1} up to 11 {mu}Sv.h{sup -1}. The study indicates that the area passive neutron dosemeter was able to detect accumulated doses as low as 40 nSv.h{sup -1}, which could not be detected with the available active neutron dosemeters. The results of the study also indicate that an additional shielding is required to bring the dose rates down to background level. The present investigation suggests extending this study to find the contribution of doses from fast neutrons around the neutron source storage area using NTDs through proton recoil. The significance of this passive technique is that it is highly sensitive and does not require any electronics or power supplies, as is the case in active systems. (author)

  13. Eurados trial performance test for photon dosimetry

    DEFF Research Database (Denmark)

    Stadtmann, H.; Bordy, J.M.; Ambrosi, P.

    2001-01-01

    Within the framework of the EURADOS Action entitled Harmonisation and Dosimetric Quality Assurance in Individual Monitoring for External Radiation, trial performance tests for whole-body and extremity personal dosemeters were carried out. Photon, beta and neutron dosemeters were considered...... 312 single results, 26 fell outside the limits of the trumpet curve and 32 were outside the range 1/1.5 to 1.5. Most outliers resulted from high energy R-F irradiations without electronic equilibrium. These fields are not routinely encountered by many of the participating dosimetry services...

  14. Implantation of radiation qualities for mammography in accordance with the IEC 61627 and TRS 457 criteria; Implantacao das qualidades de radiacao para mamografia, segundo os criterios da IEC 61627 e do TRS 457

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Evandro J.; David, Mariano G.; Almeida, Carlos Eduardo de, E-mail: pires@lcr.uerj.b [Universidade do Estado do Rio de Janeiro (LCR/UERJ), RJ (Brazil). Lab de Ciencias Radiologicas; Peixoto, J. Guilherme, E-mail: guilhem@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In this work it is discussed the technical conditions of the implantation of radiation qualities adequate for dosemeter applied to mammography at the Radiological Science Laboratory (RSL) of the University of State of Rio de Janeiro, Brazil. It performed tests for evaluation the homogeneity of the radiation field, the scattering, the half-layers and the system stability. The test results point for adequacy of the laboratory installed at the LCR for calibration of the mentioned dosemeters in seven qualities of radiation and the expanded uncertainty with better capacity of measurement at those qualities was of {+-}1.8% (k = 2)

  15. Dosimetry in a torso phantom during a mammography; Dosimetria en un fantoma de torso durante una mastografia

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez O, M.; Duran M, H. A. [Universidad de Sonora, Blvd. Luis Encinas y Rosales s/n, Hermosillo 93000, Sonora (Mexico); Pinedo S, A.; Salas L, M. A.; Hernandez D, V. M.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, IPN, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Ventura M, J. [Hospital General de Zona No. 1, IMSS, Interior Alameda 45, 98000 Zacatecas (Mexico)

    2009-10-15

    Two dosimetric magnitudes, the absorbed dose and the kerma in air to the entrance of torso have been determined. These dosimetric magnitudes are due to the radiation that is dispersed in the mammary gland when the patient undergoes a mammography study. The kerma to the entrance of the torso and the absorbed dose by the torso was obtained in a phantom of paraffin and with thermoluminescent dosemeters of ZrO{sub 2}. The dosemeters were placed on the surface of the torso phantom while the mammography was carried out. (author)

  16. Study of T L LiF: Mg,Ti (Model JR1152C) material for its use in the environmental monitoring; Estudio del material TL LiF: Mg, Ti (JR1152C) para su empleo en el monitoreo ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Molina P, D.; Diaz B, E.; Prendes A, M. [Centro de Proteccion e Higiene de las Radiaciones, CPHR, Apdo. postal 6195, Habana 6, CP 10600, Ciudad Habana (Cuba)

    1999-07-01

    In order to evaluate the possibility to use the T L material of LiF: Mg,Ti (Model JR1152C) as environmental dosemeter it was realized its characterization of it according to the established criterion in the standard IEC-1066. The properties studied were: homogeneity of the lot, reproducibility, response linearity, detection threshold, auto irradiation, residual signal, response pride (fading) and angular dependence. The results prove the compliment of the IEC requirements and therefore the applicability of this dosemeter in the environmental monitoring. (Author)

  17. Thermoluminescent response of CaSO{sub 4}: Dy + PTFE to beta particles; Respuesta termoluminiscente de CaSO{sub 4}: Dy + PTFE a particulas beta

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre C, A.; Azorin N, J. [Colegio de Bachilleres No. 13, Xochimilco-Tepepan, 16000 Mexico D.F. (Mexico)

    2000-07-01

    In this work the results of studying the thermoluminescent properties of CaSO{sub 4}: Dy + PTFE are presented when it is irradiated with beta particles. The conclusion was the obtention of the Tl response curve in function of dose is that to desexcite the dosemeters at temperature 300 C during 30 minutes and after that were irradiated at different times in groups and to do the reading of dosemeter, it can be observed that a greater irradiation time major is the Tl response and this depends of the material has been used. (Author)

  18. Thermoluminescent relative efficiencies of TLD-100 for nitrogen ions respect of gamma radiation; Eficiencias termoluminiscentes relativas de TLD-100 para iones de nitrogeno respecto de radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Concha S, K. [UNAM, Facultad de Ciencias, 04510 Mexico D.F. (Mexico); Avila, O. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Gamboa de Buen, I. [ICN-UNAM, 04510 Mexico D.F. (Mexico); Rodriguez V, M.; Buenfil, A.E.; Ruiz T, C.; Brandan, M.E. [IFUNAM, 04510 Mexico D.F. (Mexico)

    2004-07-01

    The purpose of this work is to measure the thermoluminescent relative efficiency of those TLD-100 dosemeters irradiated with nitrogen ions with respect to the gamma radiation of {sup 60} Co, in function of the linear energy transfer (LET). Two energy of such nitrogen ions were selected that has the same value from LET when impacting in the dosemeters but with E{sub 1} energy (4.8 MeV) and E{sub 2} (9.95 MeV) smaller and greater respectively that the energy of the Bragg peak. (Author)

  19. Surface plasmon coupled chemiluminescence during adsorption of oxygen on magnesium surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hagemann, Ulrich [Interdisciplinary Center for the Analytics on the Nanoscale (ICAN) and Center for Nanointegration Duisburg-Essen (CENIDE), Carl-Benz-Str. 199, 47057 Duisburg (Germany); Nienhaus, Hermann, E-mail: hermann.nienhaus@uni-due.de [Faculty of Physics, University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE), Lotharstr. 1, 47048 Duisburg (Germany)

    2015-12-28

    The dissociative adsorption of oxygen molecules on magnesium surfaces represents a non-adiabatic reaction exhibiting exoelectron emission, chemicurrent generation, and weak chemiluminescence. Using thin film Mg/Ag/p-Si(111) Schottky diodes with 1 nm Mg on a 10-60 nm thick Ag layer as 2π-photodetectors, the chemiluminescence is internally detected with a much larger efficiency than external methods. The chemically induced photoyield shows a maximum for a Ag film thickness of 45 nm. The enhancement is explained by surface plasmon coupled chemiluminescence, i.e., surface plasmon polaritons are effectively excited in the Ag layer by the oxidation reaction and decay radiatively leading to the observed photocurrent. Model calculations of the maximum absorption in attenuated total reflection geometry support the interpretation. The study demonstrates the extreme sensitivity and the practical usage of internal detection schemes for investigating surface chemiluminescence.

  20. Electron and ion induced electron emission from metals and insulators

    CERN Document Server

    Steinbatz, M

    2001-01-01

    gradually exposed to oxygen as an experimental probe. The experimental data are fitted with an analytical model, that is able to describe the observed kinetics. The fit parameters give absolute values of sticking probabilities and of surface reaction rates. During oxidation of aluminum and magnesium also spontaneous emission of electrons (exoelectrons) is observed. This effect is quantitatively studied for different oxygen partial pressures. The experimental data also indicate a significant influence of the surface morphology on the exoemission process. An important consequence of atomic collisions in solids is ionization leading to electron ejection from the target atoms with subsequent migration through the solid. A certain fraction of these electrons finally reaches the surface and is ejected into vacuum. A standard measurement of this phenomenon is the observation of the particle (electron, ion) induced electron emission yield g, defined as the average number of ejected electrons per incoming projectile. ...

  1. New luminescence measurement facilities in retrospective dosimetry

    DEFF Research Database (Denmark)

    Lapp, Torben; Jain, Mayank; Thomsen, Kristina Jørkov

    2012-01-01

    thermoelectrically cooled NIR sensitive PMT (detection window peak at 855 nm, FWHM 27 nm). Software and electronics have been modified to allow standard TL and OSL measurements in the same sequence as RL measurements. Together with a new bleaching source based on a high-power UV LED (395 nm; 700 mW/cm2......), this facility has been used to measure natural doses in feldspar using the decaying NIR RL signal.Secondly, we present a method for mapping radiation field of the built-in 90Sr/90Y β-source and estimating grain-location specific dose-rates. This is important for the accuracy of single grain results, when......This paper gives a review of recent developments in luminescence measurement facilities on the Risø TL/OSL reader including radio-luminescence (RL), exo-electron and violet stimulation attachments, and a method for characterising and if necessary correcting for beta irradiation source non...

  2. Radiation detector with spodumene

    Energy Technology Data Exchange (ETDEWEB)

    D' Amorim, Raquel Aline P.O.; Lima, Hestia Raissa B.R.; Souza, Susana O. [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Fisica; Sasaki, Jose M., E-mail: sasaki@fisica.ufc.b [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Fisica; Caldas, Linda V.E., E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    In this work, {beta}-spodumene potentiality as a radiation detector was evaluated by making use of thermoluminescence (TL) and thermally stimulated exoelectron emission (TSEE) techniques. The pellets were obtained from the {beta}-spodumene powder mixed with Teflon followed by a sintering process of thermal treatments of 300 deg/30 min and 400 deg/1.5 h. The samples were irradiated in standard gamma radiation beams with doses between 5 Gy and 10 kGy. The TL emission curve showed a prominent peak at 160 deg and in the case of TSEE a prominent peak at 145 Celsius approximately. Initial results show that the material is promising for high-dose dosimetry. (author)

  3. Non-adiabatic processes in the charge transfer reaction of O{sub 2} molecules with potassium surfaces without dissociation

    Energy Technology Data Exchange (ETDEWEB)

    Krix, David; Nienhaus, Hermann, E-mail: hermann.nienhaus@uni-due.de [Faculty of Physics, University of Duisburg-Essen and Center of Nanointegration Duisburg-Essen (CENIDE), Lotharstr. 1, D-47048 Duisburg (Germany)

    2014-08-21

    Thin potassium films grown on Si(001) substrates are used to measure internal chemicurrents and the external emission of exoelectrons simultaneously during adsorption of molecular oxygen on K surfaces at 120 K. The experiments clarify the dynamics of electronic excitations at a simple metal with a narrow valence band. X-ray photoemission reveals that for exposures below 5 L almost exclusively peroxide K{sub 2}O{sub 2} is formed, i.e., no dissociation of the molecule occurs during interaction. Still a significant chemicurrent and a delayed exoelectron emission are detected due to a rapid injection of unoccupied molecular levels below the Fermi level. Since the valence band width of potassium is approximately equal to the potassium work function (2.4 eV) the underlying mechanism of exoemission is an Auger relaxation whereas chemicurrents are detected after resonant charge transfer from the metal valence band into the injected level. The change of the chemicurrent and exoemission efficiencies with oxygen coverage can be deduced from the kinetics of the reaction and the recorded internal and external emission currents traces. It is shown that the non-adiabaticity of the reaction increases with coverage due to a reduction of the electronic density of states at the surface while the work function does not vary significantly. Therefore, the peroxide formation is one of the first reaction systems which exhibits varying non-adiabaticity and efficiencies during the reaction. Non-adiabatic calculations based on model Hamiltonians and density functional theory support the picture of chemicurrent generation and explain the rapid injection of hot hole states by an intramolecular motion, i.e., the expansion of the oxygen molecule on the timescale of a quarter of a vibrational period.

  4. Retrospective dosimetry in irradiated foods; Dosimetria retrospectiva en alimentos irradiados

    Energy Technology Data Exchange (ETDEWEB)

    Calderon, T. [Universidad Autonoma de Madrid, Facultad de Ciencias, Dpto. Quimica Agricola, Geologia, Geoquimica, Cantoblanco, Madrid (Spain)

    1999-07-01

    The main objective of this communication is to show the potentiality of certain minerals which accompany the foods (grasses, spices and seasonings) as potential dosemeters and its possible application in the absorbed dose calculations by the same in its hygienic sanitary treatment. (Author)

  5. Remote system for measurement of radon alpha emitter for population safety guards; Sistema remoto de medicion de radon alfa emisor para la salvaguarda poblacional-3599

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Vasquez, E-mail: jesus.vasguez@lnl.infn.it [Istituto Nazionale di Fisica Nucleare, Legnaro (Italy). Laboratorio Nazionale di Legnaro; Sajo-Bohus, Laszlo; Palacios, Daniel; Barros, Haydn, E-mail: sajobohus@gmail.com, E-mail: sanjuro.perdomo@gmail.com, E-mail: lab.nuclear@gmail.com [Universidad Simon Bolivar (USB), Caracas (Venezuela, Bolivarian Republic of). Laboratorio de Fisica Nuclear

    2013-07-01

    The objective of this research project is to study the OSL properties for high doses of dosemeters traditionally applied in thermoluminescent dosimetry (TL), as CaF2: Dy (TLD 200) and CaF2: Mn (TLD 400), and thus verify the applicability of OSL technique in high-dose dosimetry.

  6. Metrological legal frame in the field of the photon dosimetry of radiotherapy in Cuba; Marco metrologico legal en el campo de la dosimetria fotonica de radioterapia en Cuba

    Energy Technology Data Exchange (ETDEWEB)

    Walwyn S, G.; Gutierrez L, S.; Gonzalez R, N. [CPHR, Calle 20 No. 4113 e/41 y 47, Playa C.P. 11300, La Habana (Cuba)]. e-mail: gonzalo@cphr.edu.cu

    2006-07-01

    The Clinical Dosimetry in the planning of the doses to administer to patients under radiant treatment is of great importance. At the moment the clinical dosemeters its are manufactured with a high technology but errors of production or manipulation cannot be discarded that lead to errors in this planning. It also exists, a group of metrological and of operation parameters that are not checked in a routine calibration, and for those that are checked, legal base that restricts its use in cases of bad operation doesn't exist. This motivated to the Cuban standard elaboration NC 352:2005, for the verification of reference dosemeters of radiotherapy, process that trafficked for an exhaustive search and study of standards and international technical reports, selecting as base document, the standard IEC 60731:1997, for essays of approval of model of clinical dosemeters used in radiotherapy. The present article shows the main technical aspects considered and the requirements and verification methods for the declaration of aptitude of the dosemeters. This document constitutes the scientific base for the implementation from a verification service to national level and an important contribution to the standardization of the metrology of ionizing radiations of Cuba. (Author)

  7. Assessment of a new p-Mosfet usable as a dose rate insensitive gamma dose sensor

    Energy Technology Data Exchange (ETDEWEB)

    Vettese, F.; Donichak, C.; Bourgeault, P. [DGA/Centre d`etudes du Bouchet/DPN, 31 - Toulouse (France)

    1995-12-31

    Dosimetric response of unbiased MOS devices has been assessed at dose rates greater than 2000 cGy/h. Application have been made to a personal dosemeter / dose rate meter to measure the absorbed tissue dose received in the case of acute external irradiation. (D.L.). 10 refs.

  8. Dose measurements in space by the Hungarian Pille TLD system

    Energy Technology Data Exchange (ETDEWEB)

    Apathy, I.; Deme, S. E-mail: deme@sunserv.kfki.hu; Feher, I.; Akatov, Y.A.; Reitz, G.; Arkhanguelski, V.V

    2002-10-01

    Exposure of crew, equipment, and experiments to the ambient space radiation environment in low Earth orbit poses one of the most significant problems to long-term space habitation. Accurate dose measurement has become increasingly important during the assembly (extravehicular activity (EVA)) and operation of space stations such as on Space Station Mir. Passive integrating detector systems such as thermoluminescent dosemeters (TLDs) are commonly used for dosimetry mapping and personal dosimetry on space vehicles. The well-known advantages of passive detector systems are their independence of power supply, small dimensions, high sensitivity, good stability, wide measuring range, resistance to environmental effects, and relatively low cost. Nevertheless, they have the general disadvantage that for evaluation purposes they need a laboratory or large--in mass and power consumption--terrestrial equipment, and consequently they cannot provide time-resolved dose data during long-term space flights. KFKI Atomic Energy Research Institute (KFKI AEKI) has developed and manufactured a series of thermoluminescent dosemeter systems for measuring cosmic radiation doses in the 10 {mu}Gy to 10 Gy range, consisting of a set of bulb dosemeters and a compact, self-contained, TLD reader suitable for on-board evaluation of the dosemeters. By means of such a system, highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations as well as on the Space Shuttle. A detailed description of the system is given and the comprehensive results of these measurements are summarised.

  9. Evaluation of the absorbed dose in odontological computerized tomography; Avaliacao da dose absorvida em tomografia computadorizada odontologica

    Energy Technology Data Exchange (ETDEWEB)

    Legnani, Adriano; Schelin, Hugo R.; Rocha, Anna Silvia P.S. da, E-mail: schelin@utfpr.edu.b, E-mail: anna@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2011-10-26

    This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

  10. Report of safety of the characterizing system of radioactive waste; Informe de seguridad del sistema caracterizador de desechos radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Angeles C, A.; Jimenez D, J.; Reyes L, J. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1998-09-15

    Report of safety of the system of radioactive waste of the ININ: Installation, participant personnel, selection of the place, description of the installation, equipment. Proposed activities: operations with radioactive material, calibration in energy, calibration in efficiency, types of waste. Maintenance: handling of radioactive waste, physical safety. Organization: radiological protection, armor-plating, personal dosemeter, risks and emergency plan, environmental impact, medical exams. (Author)

  11. Viability evaluation of the reading system by CCD for application at the Fricke xylenol gel dosimetry developed by IPEN-Sao Paulo, Brazil; Avaliacao de viabilidade do sistema de leitura por CCD para aplicacao na dosimetria Fricke xilenol gel desenvolvido no IPEN-Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Mangueira, Thyago Fressatti; Dias, Daniel Menezes; Campos, Leticia Lucente, E-mail: thyagomangueira@usp.b, E-mail: dmdias@ipen.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    The use of chambers with coupled charge devices - CCD, is already used by research centres for the dose evaluation applying the Fricke xylenol gel dosemeter. This work evaluates the application of this optical reading technique for the FXG developed at the IPEN, Sao Paulo, Brazil

  12. The interventional radiology: means of reduction and optimization of medical personnel exposure; La radiologie interventionnelle: moyens de reduction et d'optimisation de l'exposition du personnel medical

    Energy Technology Data Exchange (ETDEWEB)

    Maccia, C. [Centre d' Assurance de Qualite des Applications Technologiques dans le Domaine de la Sante, CAATS, 92 - Bourg-la-Reine (France); Vano, E.; Gonzalez, L.; Guibelalde, E. [Faculdad de Medicina, Universidad de Madrid (Spain)

    1998-07-01

    The measures envisaged to make an optimization of the radiation protection are in the use of materials adapted to the situation, the use of dosemeters devoted to the doses evaluation for particularly sensitive organs , the introduction of ophthalmic examinations and finally, the information and training of every category of personnel in radiation protection. (N.C.)

  13. Recovery of α-Al{sub 2}O{sub 3} from ionizing radiation dosimetric sensors

    Energy Technology Data Exchange (ETDEWEB)

    Sanches, Edgar Aparecido, E-mail: sanches.ufam@gmail.com [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Dept. de Fisica; Costalonga, Ademir Geraldo Cavallari; Mascarenhas, Yvonne Primerano [Universidade de Sao Paulo (IFSC/USP), Sao Carlos, SP (Brazil). Institute de Fisica; Nascimento, Luana de Freitas [Belgium Nuclear Research Centre, SCK-CEN, Mol (Belgium); Mascarenhas, Yvone Maria [SAPRA S/A Servico de Assessoria e Protecao Radiologica, Sao Carlos, SP, (Brazil)

    2015-01-15

    Corundum, sapphire or α-Al{sub 2}O{sub 3} is an important technological material in many optical and electronic applications such as solid-state lasers, optical windows and, more recently, as a radiation detector. Landauer (Glenwood, IL, USA) accumulated large number of archived and stored Luxel™ dosemeters composed of Al{sub 2}O{sub 3}:C, which were subjected to a recovery process. Due to the importance of this advanced crystalline material in OSL dosimetry, a recovery process was developed based on the dosemeters calcination and Al{sub 2}O{sub 3}:C has been reused in manufacturing of new dosemeters. This paper does not aim to optimize the recovery process, but provides an opportunity to study the involved process parameters and to recover this valuable crystalline material from used dosemeters. To the best of our knowledge no other recovery process involving this dosimetric material was described in scientific literature. Fourier Transform Infrared Spectrometry (FTIR), Thermogravimetry/Differential Thermoanalysis (TG/DTA), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Optically Stimulated Luminescence (OSL) and Rietveld Refinement were used to characterize the recovered material and to check for the stability of its structural and dosimetric properties. (author)

  14. Thermoluminescent response of LiF before variation of the heating rate; Respuesta termoluminiscente de LiF ante variacion de la tasa de calentamiento

    Energy Technology Data Exchange (ETDEWEB)

    Barrios, R. [Facultad de Quimica, UAEM, 50000 Toluca, Estado de Mexico (Mexico); Avila, O. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-01

    Comparisons of glow curves of lithium fluoride dosemeters TLD-100 measured to two heating rates with the purpose of quantifying the change in the temperature of the peaks 5 and 7 for the thermoluminescent reader equipment Harshaw 4000 of the thermoluminescence laboratory of the ININ were carried out. (Author)

  15. Effective dose to staff from interventional procedures: estimations from single and double dosimetry.

    Science.gov (United States)

    Kuipers, Gerritjan; Velders, Xandra L

    2009-09-01

    The exposure of 11 physicians performing interventional procedures was measured by means of two personal dosemeters. One personal dosemeter was worn outside the lead apron and an additional under the lead apron. The study was set up in order to determine the added value of a dosemeter worn under the lead apron. With the doses measured, the effective doses of the physicians were estimated using an algorithm for single dosimetry and two algorithms for double dosimetry. The effective doses calculated with the single dosimetry algorithm ranged from 0.11 to 0.85 mSv in 4 weeks. With the double dosimetry algorithms, the effective doses ranged from 0.02 mSv to 0.47 mSv. The statistical analysis revealed no significant differences in the accuracy of the effective doses calculated with single or double dosimetry algorithms. It was concluded that the effective dose cannot be considered a more accurate estimate when two dosemeters are used instead of one.

  16. Albedo neutron dosimetry in Germany: regulations and performance.

    Science.gov (United States)

    Luszik-Bhadra, M; Zimbal, A; Busch, F; Eichelberger, A; Engelhardt, J; Figel, M; Frasch, G; Günther, K; Jordan, M; Martini, E; Haninger, T; Rimpler, A; Seifert, R

    2014-12-01

    Personal neutron dosimetry has been performed in Germany using albedo dosemeters for >20 y. This paper describes the main principles, the national standards, regulations and recommendations, the quality management and the overall performance, giving some examples. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Dosimetric evaluation of radiation attenuator glove prototype for containment of radiopharmaceuticals preparation; Evaluation dosimetrique d'un prototype de gant radioattenuateur pour enceintes de preparation des medicaments radiopharmaceutiques

    Energy Technology Data Exchange (ETDEWEB)

    Bouchet, F.; Machefert, N.; Lacoeuille, F.; Le Jeune, J.J.; Couturier, O. [CHU d' Angers, Service de medecine nucleaire, 49 (France); Vannier-Cahouet, A. [CHU d' Angers, Service de pharmacie, 49 (France); Morel, O. [CRLCC Paul-Papin, service de medecine nucleaire, 49 - Angers (France)

    2010-07-01

    The prototype of radio-attenuator glove seems to show an interest in reducing the exposure of the tips for low energy isotopes handling, however these results should be consolidated in order to more accurately estimate the measurement uncertainty of the thermoluminescent dosemeters (T.L.D.) with energy of the isotope. (N.C.)

  18. Tl response of LiF: Mg, Cu, P+Ptfe at X rays of 24, 42 and 100 KeV; Respuesta TL de LiF: Mg, Cu, P+Ptfe a rayos X de 24, 42 y 100 KeV

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, P.R.; Tovar M, V.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Azorin N, J. [UAM-I, 09340 Mexico D.F. (Mexico); Furetta, C. [Universita degli Studi di Roma ' La Sapienza' , Piazzale Aldo Moro 2, 00185 Roma (Italy); Quiroz C, M.C. [Facultad de Medicina, UAEM, 50180 Toluca, Estado de Mexico (Mexico)

    2005-07-01

    In this work the obtained results of the irradiation of thermoluminescent dosemeters (Tl) of LiF: Mg,Cu,P + Ptfe with X rays for the effective radiation energy of 24, 42 and 100 keV, in an interval of Kerma in air in the sinus of the air between 0.05 and 1.0 Gy are presented. The rate of Kerma in air was determined with an ionization chamber PTW-1152, gauged by the Laboratoire Central des Industries Electriques (LCIE). As reference commercial TLD-100 dosemeters was used. The results showed that the studied Tl dosemeters presented a lineal response in the interval of mentioned Kerma. On the other hand the estimated Kerma with the Tl dosemeter in the calibration curves for X rays, were similar to the one measured with the previously gauged ionization chamber. The Tl of LiF: Mg, Cu, P + Ptfe, developed in the ININ, are highly reliable for X-ray dosimetry. (Author)

  19. Absorbed dose determination in photon fields using the tandem method

    CERN Document Server

    Marques-Pachas, J F

    1999-01-01

    The purpose of this work is to develop an alternative method to determine the absorbed dose and effective energy of photons with unknown spectral distributions. It includes a 'tandem' system that consists of two thermoluminescent dosemeters with different energetic dependence. LiF: Mg, Ti, CaF sub 2 : Dy thermoluminescent dosemeters and a Harshaw 3500 reading system are employed. Dosemeters are characterized with sup 9 sup 0 Sr- sup 9 sup 0 Y, calibrated with the energy of sup 6 sup 0 Co and irradiated with seven different qualities of x-ray beams, suggested by ANSI No. 13 and ISO 4037. The answers of each type of dosemeter are adjusted to a function that depends on the effective energy of photons. The adjustment is carried out by means of the Rosenbrock minimization algorithm. The mathematical model used for this function includes five parameters and has a gauss and a straight line. Results show that the analytical functions reproduce the experimental data of the answers, with a margin of error of less than ...

  20. Implementation of an electronic personal dosimetry system (EPD) at Oldbury-on-Severn power station.

    Science.gov (United States)

    Clarke, P W; Weeks, A R

    2001-03-01

    This article presents the implementation of an electronic personal dosemeter (EPD) as a film badge replacement at Oldbury-on-Severn power station, which is the first major site to use an approval issued by the UK Health and Safety Executive (HSE) for dose measurement by an EPD. The practicalities and history behind the introduction of an EPD for personal dosimetry are described.

  1. National Laboratory of Ionizing Radiation Metrology - Brazilian CNEN; Laboratorio Nacional de Metrologia das Radiacoes Ionizantes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    The activities of the Brazilian National Laboratory of Ionizing Radiations Metrology are described. They include research and development of metrological techniques and procedures, the calibration of area radiation monitors, clinical dosemeters and other instruments and the preparation and standardization of reference radioactive sources. 4 figs., 13 tabs.

  2. Alanine/RPE dosimetry in the process of blood irradiation; Dosimetria alanina/RPE en el proceso de irradiacion de sangre

    Energy Technology Data Exchange (ETDEWEB)

    Chen, F.; Covas, D.T.; Baffa, O. [Departamento de Fisica e Matematica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto-SP (Brazil)

    2000-07-01

    A set of eighty dosemeters approximately of Dl- alanine was proportioned to the Hemo center of Hospital das Clinicas of Medicine Faculty at Ribeirao Preto (HC-FRMP) in the Sao Paulo University, with the purpose to realize a quality control of the radiation dose supplied to blood bags. These dosemeters were divided in eight groups and irradiated for a two months period.The dosemeters were adhered to the bags and arranged inside of an acrylic box filled water with dimensions: (40x40x20) cm{sup 3}. The box irradiation was made using two fields parallel-opposed of (40x40) cm{sup 2} at 80 cm distance source-surface, in the Radiotherapy Service of HC-FMRP, with a {sup 60} Co teletherapy unit. The irradiation time was sufficient to supply a dose of 20 Gy approximately in the box center. The RPE measures were realized in a Varian E-4 spectrometer operating in X-band. For the total of dosemeters and for the irradiation volume, the minimum and maximum doses were of 14 Gy and 23 Gy respectively. The mean dose was (18{+-}2) Gy (1 {sigma}), and the variability coefficient 11 %. Around 5 % of the bags received a dose under of the recommended limit by the Brazilian legislation and as consequence, the exposure time was increased. (Author)

  3. Stability of the response and dependence of the optical signal as function of dose rate of the alanine gel dosimeter for electron clinic beams; Estabilidade da resposta e dependencia do sinal optico em funcao da taxa de dose do dosimetro alanina gel para feixes clinicos de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber Feijo; Dias, Daniel Menezes; Campos, Leticia Lucente, E-mail: cfsilva@ipen.b, E-mail: dmdias@ipen.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    This work evaluates the stability of response and the dependence on the optical response of dose rate of the alanine gel solution developed at the IPEN, Sao Paulo, Brazil, for possible future usage as 3D dosemeter in the medical area, as the area is lack of measure instrumentation for three dimension dose

  4. A search for IRSL-Active dosimeters with enhanced sensitivity : a spectroscopic survey

    DEFF Research Database (Denmark)

    Poolton, N.R.J.; Bøtter-Jensen, L.; Johnson, O.

    1997-01-01

    The spectral and radiation dose characteristics of a range of previously uninvestigated alumine-silicate materials are surveyed, with the intention of searching for alternative, high sensitivity materials that could potentially be used as InfraRed Stimulated Luminescence (IRSL) dosemeters...

  5. Maintenance of medical nuclear equipment. A proposal for quality control in radiotherapy; Manutencao de instrumentacao nuclear utilizada na medicina. Uma proposta de solucao na area de controle de qualidade em radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Paulo H.B. [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil). Div. de Engenharia

    1996-12-31

    A project of quality control in radiotherapy that is been implemented by Instituto de Radioprotecao e Dosimetria from Brazilian National Energy Commission (CNEN) in cooperation with International Atomic Energy Agency is described. The establishment of a laboratory for the maintenance of medical dosemeters is proposed

  6. Stability of the post irradiation traps in LiF: Mg, Cu, P; Estabilidad de las trampas posradiacion en LiF: Mg, Cu, P

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, P.R. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Furetta, C. [Physics Department, Rome University ' ' La Sapienza' ' , Rome (Italy); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2004-07-01

    In this work the results of the study of the stability of the traps are presented in dosemeters Tl of LiF: Mg,Cu,P, irradiated with gamma radiation of {sup 60} Co. The studied dosemeters were of LiF: Mg,Cu,P + Ptfe, developed in the ININ, taking like reference to the commercial dosemeter GR200A of Chinese manufacture. Before being exposed to the radiation, the dosemeters received their standard treatment from having erased, two hours after the irradiation they took the initial readings. The dosemeters faded again and they were irradiated to the same dose, soon after they stayed under normal conditions, protected of the light, later on they were taken their readings periodically during six months. The readings taken Tl the same day of the irradiation presented four peaks whose energy, determined by the deconvolution method were; 1.30 {+-} 0.01 eV, 1.50 {+-} 0.01 eV, 1.70 {+-} 0.01 eV and 2.58 {+-} 0.02 eV, for LiF: Mg,Cu,P + Ptfe, while GR200A stops the energy they were: 1.33 {+-} 0.11 eV, 1.58 {+-} 0.11 eV, 1.73 {+-} 0.11 eV and 2.60 {+-} 0.03 eV. In both cases the peak 1, with the energy but it lowers, it disappears completely after some later hours to the irradiation, while the peak 2, it disappears completely after 122 days for the local dosemeter and after 94 days for the commercial dosemeter. The energy of the peaks 3 and 4 that remained visible during the whole period of study it was: 1.38 {+-} 0.01 eV and 2.65 {+-} 0.01 eV, for LiF: Mg,Cu,P + Ptfe respectively, in the same order for GR200A, the energies were: 1.51 {+-} 0.02 eV and 2.64 {+-} 0.03 eV. In all the cases the peaks with energy below 2 eV, showed tendency to the drop, while the main peak, showed certain tendency to increase, as they show it the results. (Author)

  7. Tenth ORNL Personnel Dosimetry Intercomparison Study

    Energy Technology Data Exchange (ETDEWEB)

    Swaja, R.E.; Chou, T.L.; Sims, C.S.; Greene, R.T.

    1985-03-01

    The Tenth Personnel Dosimetry Intercomparison Study was conducted at the Oak Ridge National Laboratory during April 9-11, 1984. Dosemeter badges from 31 participating organizations were mounted on 40cm Lucite phantoms and exposed to a range of dose equivalents which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor served as the only source of radiation for eight of the ten irradiations which included a low (approx. 0.50 mSv) and high (approx. 10.00 mSv) neutron dose equivalent run for each of four shield conditions. Two irradiations were also conducted for which concrete- and Lucite-shield reactor irradiations were gamma-enhanced using a /sup 137/Cs source. Results indicated that some participants had difficulty obtaining measurable indication of neutron and gamma exposures at dose equivalents less than about 0.50 mSv and 0.20 mSv, respectively. Albedo dosemeters provided the best overall accuracy and precision for the neutron measurements. Direct interaction TLD systems showed significant variation in accuracy with incident spectrum, and threshold neutron dosemeters (film and recoil track) underestimated reference values by more than 50%. Gamma dose equivalents estimated in the mixed fields were higher than reference values with TL gamma dosemeters generally yielding more accurate results than film. Under the conditions of this study in which participants had information concerning exposure conditions and radiation field characteristics prior to dosemeter evaluation, only slightly more than half of all reported results met regulatory standards for neutron and gamma accuracy. 19 refs., 2 figs., 29 tabs.

  8. Measurement of dose equivalent with personal dosemeters and instrumentation of radiological protection in the new operative ICRU magnitudes, for external fields of beta radiation. Part III. Determination of the joint of factors of angular conversion for the secondary source pattern Nr. - 86 Of (1850) MBq; Medicion de dosis equivalente con dosimetros personales e instrumentacion de proteccion radiologica en las nuevas magnitudes operativas ICRU, para campos de radiacion Beta externos. Parte III. Determinacion del conjunto de factores de conversion angular para la fuente patron secundario Nr.- 86 de (1850) MBq

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1994-02-15

    It determined the assembly of factors of angular conversion T(0;{alpha}), for the source secondary pattern of {sup 90}Sr/{sup 90}Y (1850 MBq) at a distance detecting source of 30 cm, in the following angles: 0, 15, 30, 45, 60 and 75{sup 0}. Obtaining the values of: 1.01, 1.05, 1.13, 1.19 and 0.95, respectively. Their Global uncertainty is smaller to 1.5% for all the cases and its percentage differences with regard to the values reported by the Draft of the norm ISO 6980(1992) they are smaller to 3.0% for all the cases.The technique employee was that of the extrapolation Chamber and the treatment of the uncertainties is made of agreement with the recommendations of the BIPM. (Author)

  9. Studies of aluminium nitride ceramics for application in UV dosimetry

    DEFF Research Database (Denmark)

    Trinkler, L.; Bøtter-Jensen, L.; Christensen, P.

    2000-01-01

    The study is reported of the ceramic material AlN-Y2O3 as a potential luminescence dosemeter for the detection of UV radiation. Both the thermoluminescence and the optically stimulated luminescence properties of the material have been studied after exposure to UV radiation and compared with those...... of the widely used dosemeter material Al2O3:C. It has been shown that AlN-Y2O3 ceramics exhibit three orders of magnitude higher sensitivity to UV radiation than does Al2O3,:C over a broad spectral region. The thermoluminescence from AlN-Y2O3 is characterised by linear dose dependence over a wide range...

  10. Retrospective assessment of environmental dose rates using optically stimulated luminescence from Al2O3:C and quartz

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Banerjee, D.; Jungner, H.

    1999-01-01

    radionuclide concentrations. It is concluded that the excellent OSL characteristics of Al2O3:C are attractive for use in short-term evaluations of the environmental dose rates. Depth dose profiles were also measured in bricks, after irradiation in the laboratory with Cs-137 gamma rays, using (1).Al2O3:C single...... of the initial accident radiation was lower than that of Cs-137 gamma rays.......As part of our continuing work on assessing the usefulness of natural and artificial dosemeters in retrospective accident dosimetry, the natural photon dose rates within bricks have been measured using the optically stimulated luminescence (OSL) from Al2O3:C single crystal dosemeters. These were...

  11. An intercomparison of the thermoluminescent efficiency of various preparations of lithium fluoride

    CERN Document Server

    Driscoll, C M H

    1977-01-01

    Possible alternative sources of supply of lithium fluoride to that used at present in the NRPB automated TLD system dosemeter are being considered on the grounds of economy and quality control. Initial measurements on the thermoluminescent properties and efficiency of various preparations of lithium fluoride are described, including the Harshaw TLD-700 which is currently in use in the automated thermoluminescent dosemeter. Material obtained from British Nuclear Fuels Ltd (which may be an atypical batch) showed 75% of the sensitivity of the Harshaw material, with around 20% fading of the signal after 1 month's storage. French material, obtained from Desmarquest and Carbonisation Entreprise et Ceramique and used by the Commissariat a l'Energie Atomique, showed good fading resistance but, after standard preparational treatments, was only half as sensitive in the thermoluminescent response. Without additional treatments to improve the characteristics of these materials, they cannot be considered as being satisfac...

  12. A Portable TLD System for Environmental Monitoring of Hungary's Paks Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    German, E.; Ranga, T. [Paks Nuclear Power Plant, Paks (Hungary); Deme, S.; Apathy, I. [Budapest (Hungary)

    1999-07-01

    The microprocessor-controlled, portable, rechargeable battery operated TLD system Pille 94E developed in the Atomic Energy Research Institute (AERI) is being utilised for environmental monitoring of the Paks Nuclear Power Plant (NPP). The CaSO{sub 4}:Dy bulb dosemeters of the system are sited at 25 points within a radius of 30 km of the NPP. At these same locations, CaSO{sub 4}:Dy powder dosemeters for laboratory reading are also sited and at eight locations the dose is also measured with a GM counter telemetric system. The reproducibility and time dependence of the doses measured with the portable system are given and compared with those measured by the other two systems. The results, in most cases, were in good agreement. Based on this experience both for the routine monitoring and for a possible accident assessment, it is considered that the portable system should be used instead of the classical TLD method. (author)

  13. New method of preparation of CaSO{sub 4}: Dy for ionizing radiation dosimetry; Nuevo metodo de preparacion del CaSO{sub 4}: Dy para dosimetria de radiacion ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Roman L, J.; Rivera M, T.; Alarcon F, G.; Guzman M, J. [CICATA-IPN, 11500 Mexico D.F. (Mexico); Azorin N, J.; Sosa F, R. [UAM-I, 09340 Mexico D.F. (Mexico); Serrano F, A.K. [Hospital Juarez General de Mexico, 07760 Mexico D.F. (Mexico)]. e-mail: holand_jeos@hotmail.com

    2008-07-01

    In this work some results of the characterization of solid state materials exposed at a gamma radiation beam coming from a {sup 60} Co bomb for medical use are presented. These thermoluminescent dosemeters are prepared and proposed for the ionizing radiations dosimetry using the thermoluminescence method. The passive dosemeters of CaSO{sub 4}: Dy are developed in the polycrystalline powder form being used a new synthesis route by means of the precipitation method. To determine the sensibility of the pellets of CaSO{sub 4}: Dy before gamma radiation, these were exposed before a gamma radiation beam coming from a {sup 60} Co bomb. The morphological and structural characteristics were also studied and present two in this work. (Author)

  14. Automatic scanning of NTA film neutron dosimeters

    CERN Document Server

    Müller, R

    1999-01-01

    At the European Laboratory for Particle Physics CERN, personal neutron monitoring for over 4000 collaborators is performed with Kodak NTA film, one of the few suitable dosemeters in the stray radiation environment of a high energy accelerator. After development, films are scanned with a projection microscope. To overcome this lengthy and strenuous procedure an automated analysis system for the dosemeters has been developed. General purpose image recognition software, tailored to the specific needs with a macro language, analyses the digitised microscope image. This paper reports on the successful automatic scanning of NTA films irradiated with neutrons from a /sup 238/Pu-Be source (E approximately=4 MeV), as well as on the extension of the method to neutrons of higher energies. The question of detection limits is discussed in the light of an application of the method in routine personal neutron monitoring. (9 refs).

  15. A comparison of different neutron spectroscopy systems at the reactor facility VENUS

    CERN Document Server

    Vanhavere, F; Chartier, J L; Itie, C; Rosenstock, W; Koeble, T; D'Errico, F

    2002-01-01

    The VENUS facility is a zero-power research reactor mainly devoted to studies on LWR fuels. Localised high-neutron rates were found around the reactor, with a neutron/gamma dose equivalent rate ratio as high as three. Therefore, a study of the neutron dosimetry around the reactor was started some years ago. During this study, several methods of neutron spectroscopy were employed and a study of individual and ambient dosemeters was performed. A first spectrometric measurement was done with the IPSN multisphere spectrometer in three positions around the reactor. Secondly, the ROSPEC spectrometer from the Fraunhofer Institut was used. The spectra were also measured with the bubble interactive neutron spectrometer. These measurements were compared with a numerical simulation of the neutron field made with the code TRIPOLI-3. Dosimetric measurements were made with three types of personal neutron dosemeters: an albedo type, a track etch detector and a bubble detector.

  16. Use of the calorimeter in the dosimetry for electron accelerators; Uso del calorimetro en la dosimetria para aceleradores de electrones

    Energy Technology Data Exchange (ETDEWEB)

    Chavez B, A

    1991-02-15

    The measure of different radiation types, with specific dosemeters, requires that the absorbed dose should be measured with accuracy by some common standard. The existent problem around the dosimetry of accelerated electrons has forced to the development of diverse detector types that after having analyzed the characteristics; dependability and reproducibility are used as dosemeters. Recently the calorimeters have been developed, with the purpose of carrying out dosimetry for electron accelerators. The RISO laboratory in Denmark, in it 10 MeV accelerator had been used for the dosimetry those water calorimeters, later on, using the principle of the water calorimeter, it was designing one similar, for the accelerator of 400 keV. Recently manufactured simple calorimeters of graphite have been used, which can be used in both accelerators of 10 MeV and 400 keV. (Author)

  17. Development of a three-dimensional radiation dosimetry system

    CERN Document Server

    Bero, M A

    2001-01-01

    effort, and minimises the cost of equipment as well as materials. A serious drawback of the Fricke gel is ion diffusion, which causes blurring of the recorded spatial distribution and much effort was given to attempts to reduce this. However it was concluded that it is possible to slow down ion diffusion but at the cost of detector sensitivity. Therefore the best way of dealing with this problem is by introducing a fast readout technique so that the dose distribution can be recorded before serious diffusion blurring has occurred. The polymer gel system normally includes acrylamide but this was avoided for safety reasons. In order to resolve the dissolved oxygen problem which makes the preparation and storage of the dosemeter difficult a modification was proposed by which oxygen would interact with other chemicals and not with the monomers in this type of dosemeter. However, research in this direction was halted as attention turned to manufacturing a convenient, safe, highly sensitive and reliable radiochromic...

  18. Personal dosimetry in terms of HP(3): Monte Carlo and experimental studies.

    Science.gov (United States)

    Ferrari, P; Gualdrini, G; Bedogni, R; Fantuzzi, E; Monteventi, F; Morelli, B

    2007-01-01

    Hp(3) has been defined as the operational quantity for eye lens dosimetry. Hp(3)/ka conversion coefficients were evaluated at the GSF (Germany) in a 30x30x15 cm3 4-elements ICRU slab phantom for various energies and incident angles through Monte Carlo. The ISO report 12,794 suggests to employ a PMMA water filled phantom, of the same dimensions, for dosemeter calibration in terms of Hp(3). The present paper briefly summarises the main aspects of a study carried out at ENEA-Radiation Protection Institute (Bologna, Italy) to provide practical procedures for the calibration of dosemeters in terms of Hp(3). Tabulations of a new set conversion coefficients and air kerma backscatter factors are provided as a function of energy and incident angle. The paper demonstrates that a more accurate approach to the dosimetric assessment in terms of Hp(3) could be rather simply introduced employing a reduced phantom.

  19. A second simulated criticality accident dosimetry experiment

    CERN Document Server

    Adams, N

    1973-01-01

    This experiment was undertaken to facilitate training in criticality dose assessment by UKAEA and BNFL establishments with potential criticality hazards. Personal dosemeters, coins, samples of hair, etc. supplied by the seven participating establishments were attached to a man-phantom filled with a solution of sodium nitrate (simulating 'body-sodium'), and exposed to a burst of radiation from the AWRE pulsed reactor VIPER. The neutron and photon doses were each several hundred rads. Participants made two sets of dose assessments. The first, made solely from the evidence of their routine dosemeters the activation of body-sodium and standard monitoring data, simulated the initial dose assessment that would be made before the circumstances of a real incident were established. The second was made when the position and orientation of the phantom relative to the reactor and the shielding (20 cm of copper) between the reactor core and the phantom were disclosed. Neutron and photon dose assessments for comparison wit...

  20. Determination of the neutron spectra in the treatment room of a linear accelerator for radiotherapy; Determinacion de los espectros de neutrones en la sala de tratamiento de un acelerador lineal para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R. [Universidad Autonoma de Zacatecas, Cuerpo Academico de Radiobiologia, A.P. 336, 98000 Zacatecas (Mexico); Barquero, R. [Hospital Universitario Rio Hortega, Valladolid (Spain); Mendez, R.; Iniguez, M.P. [Depto. de Fisica Teorica, Atomica, Molecular y Nuclear, Universidad de Valladolid, 47011 Valladolid (Spain)

    2003-07-01

    By means of a series of measures and Monte Carlo calculations the dosimetric characteristics of the photoneutrons have been determined that take place in volume to a linear accelerator of radiotherapy of 18 MV, LINAC, mark Siemens Mevatron model. The measures were carried out with thermoluminescent dosemeters TLD 600 and TLD 700 that were naked exposed and confined with cover of Cd and Sn, inside a sphere of paraffin and inside spheres Bonner. (Author)

  1. Monitoring the eye lens: which dose quantity is adequate?

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, R [Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig (Germany); Dietze, G, E-mail: rolf.behrens@ptb.d [Paracelsusstrasse 7, D-38116 Braunschweig (Germany)

    2010-07-21

    Recent epidemiological studies suggest a rather low dose threshold (below 0.5 Gy) for the induction of a cataract of the eye lens. Some other studies even assume that there is no threshold at all. Therefore, protection measures have to be optimized and current dose limits for the eye lens may be reduced in the future. The question of which personal dose equivalent quantity is appropriate for monitoring the dose to the eye lens arises from this situation. While in many countries dosemeters calibrated in terms of the dose equivalent quantity H{sub p}(0.07) have been seen as being adequate for monitoring the dose to the eye lens, this might be questionable in the case of reduced dose limits and, thus, it may become necessary to use the dose equivalent quantity H{sub p}(3) for this purpose. To discuss this question, the dose conversion coefficients for the equivalent dose of the eye lens (in the following eye lens dose) were determined for realistic photon and beta radiation fields and compared with the values of the corresponding conversion coefficients for the different operational quantities. The values obtained lead to the following conclusions: in radiation fields where most of the dose comes from photons, especially x-rays, it is appropriate to use dosemeters calibrated in terms of H{sub p}(0.07) on a slab phantom, while in other radiation fields (dominated by beta radiation or unknown contributions of photon and beta radiation) dosemeters calibrated in terms of H{sub p}(3) on a slab phantom should be used. As an alternative, dosemeters calibrated in terms of H{sub p}(0.07) on a slab phantom could also be used; however, in radiation fields containing beta radiation with the end point energy near 1 MeV, an overestimation of the eye lens dose by up to a factor of 550 is possible.

  2. Dose profile study on computerized tomography scanning of skull with simulator object; Estudo do perfil de dose em varreduras de TC de cranio com objeto simulador

    Energy Technology Data Exchange (ETDEWEB)

    Mourao, A.P., E-mail: aprata@des.cefetmg.b [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET/MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar; Alonso, Thessa C.; Silva, Teogenes A. da, E-mail: alonso@cdtn.b, E-mail: silvata@@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-10-26

    This work presents a comparison among the dose profiles in scanning of computerized tomography of a simulator object of PMMA in its periphery region. To obtain the deposited dose at the PMMA thermoluminescent dosemeters were used positioned at the interior of PMMA simulated object longitudinal to periphery and at the center of cylinder (positions denominated North, South, East, West and Center). Eight scanning were performed of simulator object using the routine protocol for skull in eight different services of radiodiagnostic by TC

  3. A method to minimise the fading effects of LiF:Mg,Ti (TLD-600 and TLD-700) using a pre-heat technique.

    Science.gov (United States)

    Lee, YoungJu; Won, Yuho; Kang, Kidoo

    2015-04-01

    Passive integrating dosemeters [thermoluminescent dosimeter (TLD) and optically stimulated luminescence (OSL)] are the only legally permitted individual dosemeters for occupational external radiation exposure monitoring in Korea. Also its maximum issuing cycle does not exceed 3 months, and the Korean regulations require personal dosemeters for official assessment of external radiation exposure to be issued by an approved or rather an accredited dosimetry service according to ISO/IEC 17025. KHNP (Korea Hydro & Nuclear Power, LTD), a unique operating company of nuclear power plants (NPPs) in Korea, currently has a plan to extend a TLD issuing cycle from 1 to 3 months under the authors' fading error criteria, ±10%. The authors have performed a feasibility study that minimises post-irradiation fading effects within their maximum reading cycle employing pre-heating technique. They repeatedly performed irradiation/reading a bare TLD chip to determine optimum pre-heating conditions by analysing each glow curve. The optimum reading conditions within the maximum reading cycle of 3 months were decided: a pre-heating temperature of 165°C, a pre-heating time of 9 s, a heating rate of 25°C s(-1), a reading temperature of 300°C and an acquisition time of 10 s. The fading result of TLD-600 and TLD-700 carried by newly developed time temperature profile (TTP) showed a much smaller fading effect than that of current TTP. The result showed that the fading error due to a developed TTP resulted in a ∼5% signal loss, whereas a current TTP caused a ∼15% loss. The authors also carried out a legal performance test on newly developed TTP to confirm its possibility as an official dosemeter. The legal performance tests that applied the developed TTP satisfied the criteria for all the test categories. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Estimation of staff lens doses during interventional procedures. Comparing cardiology, neuroradiology and interventional radiology.

    Science.gov (United States)

    Vano, E; Sanchez, R M; Fernandez, J M

    2015-07-01

    The purpose of this article is to estimate lens doses using over apron active personal dosemeters in interventional catheterisation laboratories (cardiology IC, neuroradiology IN and radiology IR) and to investigate correlations between occupational lens doses and patient doses. Active electronic personal dosemeters placed over the lead apron were used on a sample of 204 IC procedures, 274 IN and 220 IR (all performed at the same university hospital). Patient dose values (kerma area product) were also recorded to evaluate correlations with occupational doses. Operators used the ceiling-suspended screen in most cases. The median and third quartile values of equivalent dose Hp(10) per procedure measured over the apron for IC, IN and IR resulted, respectively, in 21/67, 19/44 and 24/54 µSv. Patient dose values (median/third quartile) were 75/128, 83/176 and 61/159 Gy cm(2), respectively. The median ratios for dosemeters worn over the apron by operators (protected by the ceiling-suspended screen) and patient doses were 0.36; 0.21 and 0.46 µSv Gy(-1) cm(-2), respectively. With the conservative approach used (lens doses estimated from the over apron chest dosemeter) we came to the conclusion that more than 800 procedures y(-1) and per operator were necessary to reach the new lens dose limit for the three interventional specialties. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Development of a sealing process of capsules for surveillance test tubes of the vessel in nuclear power plants; Desarrollo de proceso de sellado de capsulas para probetas de vigilancia de la vasija en nucleoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Romero C, J.; Fernandez T, F.; Perez R, N.; Rocamontes A, M.; Garcia R, R. [ININ, Km 36.5 Carretera Mexico-Toluca, 52750 La Marquesa, Estado de Mexico (Mexico)

    2007-07-01

    The surveillance capsule is composed by the support, three capsules for impact test tubes, five capsules for tension test tubes and one porta dosemeters. The capsules for test tubes are of two types: rectangular capsule for Charpy test tubes and cylindrical capsule for tension test tubes. This work describes the development of the welding system to seal the capsules for test tubes that should contain helium of ultra high purity to a pressure of 1 atmosphere. (Author)

  6. IEC standards for individual monitoring of ionising radiation.

    Science.gov (United States)

    Voytchev, M; Ambrosi, P; Behrens, R; Chiaro, P

    2011-03-01

    This paper presents IEC/SC 45B 'Radiation protection instrumentation' and its standards for individual monitoring of ionising radiation: IEC 61526 Ed. 3 for active personal dosemeters and IEC 62387-1 for passive integrating dosimetry systems. The transposition of these standards as CENELEC (European) standards is also discussed together with the collaboration between IEC/SC 45B and ISO/TC 85/SC 2.

  7. Determination of radiation levels by neutrons in an accelerator for radiotherapy; Determinacion de niveles de radiacion por neutrones en un acelerador para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.; Salazar B, M.A. [Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, 11801 Mexico D.F. (Mexico); Genis S, R. [Fundacion Clinica Medica Sur, Puente de Piedra 150, Col. Torriello Guerra, Tlalpan 14050, Mexico D.F. (Mexico)

    1998-12-31

    It was determined the radiation levels by neutrons due to photonuclear reactions ({gamma}, n) which occur in the target, levelling filter, collimators and the small pillow blinding of a medical accelerator Varian Clinac 2100C of 18 MeV, using thermoluminescent dosemeters UD-802AS and US-809AS. The experimental values were presented for the patient level, inside and outside of the radiation field, as well as for the small pillow. (Author)

  8. Evaluation of the Sensitivity and Signal Response of the DT-702 LiF:Mg,Cu,P TLD

    Science.gov (United States)

    2007-06-27

    domestic and international shipping, as well as reducing the amount of handling required to process the TLDs each year. Additionally, the results of...60), Radium -226 (Ra-226), and Americium- 31 241(Am-241) sources, as well as a deep therapy x-ray unit. To evaluate the effects of time after...well as reduce the amount of general handling required of the dosemeters. This research will contribute to the current scientific conversation and

  9. Dosimetric study for characterization of a postal system of quality control in brachytherapy; Estudo dosimetrico para caracterizacao de um sistema postal de controle de qualidade em braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Victor Gabriel Leandro, E-mail: vgalves@inca.gov.b [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil); Queiroz Filho, Pedro Pacheco de; Santos, Denison de Souza, E-mail: queiroz@ird.gov.b, E-mail: santosd@ird.gov.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Begalli, Marcia, E-mail: begalli@uerj.b [Universidade do Estado do Rio de Janeiro (IF/UERJ), RJ (Brazil). Inst. de Fisica

    2009-07-01

    This work presents a dosimetric study of a postal system, to be developed for measurements of brachytherapy. It was projected a PMMA phantom with orifices for insertion of the high dose {sup 192}Ir source and the T L dosemeters. The system was characterized with using of Monte Carlo simulations, using the dosimetric magnitudes defined at the T G-43 of AAPM, as function of radial dose g(f)

  10. The use of Monte Carlo codes in metrology of ionizing radiations; Utilisation de codes de Monte Carlo en metrologie des rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Bathe, J.; Gouriou, J.; Daures, J.; Ostrowsky, A.; Bordy, J.M. [CEA Saclay, Dir. de la Recherche Technologique (DRT/DIMRI - LNHB), 91 - Gif sur Yvette (France)

    2003-07-01

    The use of Monte Carlo codes allows to get corrective values more exact or inaccessible by traditional methods. Here are presented several results got in te frame of dose metrology (influence of vacuum interstices in a calorimeter, influence of walls in a chemical dosemeter) as well as in this one of radioactivity metrology ( efficiency and spectra of energy deposition in a detector, spectra in energy of thick sources). (N.C.)

  11. Extra Dose Due to Extravehicular Activity During the NASA4 Mission, Measured by an On-Board TLD System

    Energy Technology Data Exchange (ETDEWEB)

    Deme, S.; Apathy, I.; Hejja, I.; Lang, E.; Feher, I. [Budapest (Hungary)

    1999-07-01

    A microprocessor-controlled on-board TLD system, 'Pille'96', was used during the NASA4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the extra dose to two astronauts in the course of their extravehicular activity (EVA). For the EVA dose measurements, CaSO{sub 4}:Dy bulb dosemeters were located in specially designed pockets of the ORLAN spacesuits. During an EVA lasting 6 h, the dose ratio inside and outside Mir was measured. During the EVA, Mir crossed the South Atlantic Anomaly three times. Taking into account the influence of these three crossings the mean EVA/internal dose rate ratio was 3.2. Internal dose mapping using CaSO{sub 4}:Dy dosemeters gave mean dose rates ranging from 9.3 to 18.3 {mu}Gy.h{sup -1} at locations where the shielding effect was not the same. Evaluation results of the high temperature region of LiF dosemeters are given to estimate the mean LET. (author)

  12. A Test of Reliability of the Personnel Dosimetry Services Authorized by CSN using Photon Beams; Control de los servicios de dosimetria personal autorizados por el CSN, usando haces de fotones

    Energy Technology Data Exchange (ETDEWEB)

    Brosed, A.; Delgado, A.; Granados, C. E.; Lopez Ortiz, G.

    1987-07-01

    In 1987 the Consejo de Seguridad Nuclear (CSN) had eight Personnel Dosimetry Services (PDS) authorized to asses the equivalent doses to the spanish occupationally exposed workers, by means of the readings from the dosemeters wear by them. An audit was carried on the PDS on behalf of CSN under the control of CIEMAT. Batches of dosemeters from each one of the PDS were irradiated to dose equivalent values which were well established by CIEMAT but kept hidden from the PDS. By comparing the true values with those obtained by the PDS, it was possible to evaluate the Services according to the analysis of the quantity Q= I B I -I- S where B is the average of the individual deviations between the dosemeters belonging to the same group and the true value as established by CIEMAT, whereas S is the standard deviation of the values inside of this same group. The results of the evaluation, which was made using the new ICRU quantities for personnel monitoring, are presented. (Author) 8 refs.

  13. Obtention of a thermoluminescent material for dosimetry of ionizing radiation; Obtencion de un material termoluminiscente para dosimetria de la radiacion ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, P.R

    1990-07-01

    The thermoluminescent dosemeters are small crystals which suffer changes in their structure by the radiation effect, being displaced the electrons toward higher energy levels. On heating the previously irradiated crystals, the electrons come back to their base state emitting light photons. The light quantity emitted is proportional to the received radiation dose. The light quantity emitted is proportional to the received radiation dose. The lithium fluoride is one of the thermoluminescent materials considered as tissue equivalents by having a low effective atomic number (Z{sub ef}). At present, the more used commercial product used of this type is the TLD-100*. In this work the obtained results in the preparation of the lithium fluoride thermoluminescent material are presented. This is activated with magnesium (Mg) and titanium (Ti), which we have labelled as: LiF: Mg, Ti. The results from the tests performed for verifying his thermoluminescent properties are presented too, as powder form as in pellets form. These tests were performed in simultaneous form with TLD-100 samples, which is considered as reference. The LiF: Mg, Ti thermoluminescent material manufactured in the ININ presents similar dosimetric characteristics to those ones of the TLD-100. Therefore being able to replace the imported dosemeters. * (TLD-100 is a commercial trademark registered by Harshaw/Filtrol (US) for LiF: Mg, Ti Tl dosemeters) (Author)

  14. Case-control study on radon exposure and lung cancer in an Italian region. Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Bochicchio, F; Nuccetelli, C. [Istituto Superiore di Sanita, Rome (Italy). Physics Lab.; Forastiere, F.; Mallone, S.; Sera, F.

    2000-05-01

    The present estimates of the lung cancer risk for the general population due to radon exposure in dwellings are generally obtained by extrapolating the risk estimates derived from epidemiologic studies on miner cohorts. However, due to uncertainties related to this extrapolation, numerous case-control studies in Europe and North America were planned to estimate directly the risk in dwellings. Most of these studies are still underway and, thanks to their similar design and compatible protocols, it will be possible to perform a pooled analysis in order to improve statistical power. One of these projects is being conducted in the Lazio region of Italy, which is one of the Italian regions with the highest levels of radon indoors. A total of 408 cases and 424 controls older than 34 years, who lived for 25 years or longer in the Lazio Region, were recruited in a hospital of Rome. Detailed information regarding smoking, and occupational exposure of the subjects were collected by interviews in hospital. Residential histories (periods and addresses) during the 35 years preceding the enrolment were ascertained for all study members from the local Register and from a short questionnaire to the subjects or to the next-of-kin, resulting in 2068 dwellings to be monitored within the Lazio region. The distribution of the number of dwellings among cases and controls was the following: 25.7% of the cases and 27.3% of the controls had lived all the preceding 35 years in a single dwelling, whereas only a minority (7.9%) changed five addresses or more. The mean number of dwellings was very similar among cases (2.47) and controls (2.50). In each dwelling, radon dosemeters were placed in both the main bedroom and living room for two consecutive six-month periods. In the second six-month period, two thermoluminescent dosemeters were also collocated in each monitored room to measure gamma radiation emitted by the building materials, in order to evaluate more comprehensively the exposure of

  15. Radiation-induced defects, energy storage and release in nitrogen solids

    Science.gov (United States)

    Savchenko, E.; Khyzhniy, I.; Uyutnov, S.; Bludov, M.; Barabashov, A.; Gumenchuk, G.; Bondybey, V.

    2017-02-01

    New trends in the study of radiation effects in nitrogen solids with a focus on the defect-induced processes are presented. An electron beam of subthreshold energy was used to generate radiation defects via electronic subsystem. Experimental techniques developed enabled us to detect neutral and charged defects of both signs. Defect production and desorption were monitored using optical and current emission spectroscopy: cathodoluminescence CL, thermally stimulated luminescence TSL and exoelectron emission TSEE along with the detection of postdesorption. Our results show stabilization and accumulation of radiation defects - ionic centres of both signs (N4 +, N3 +, N3 -), trapped electrons and radicals (N, N3). The neutralization reactions: N4 ++e-→N4 *→N2 *(a‘1Σu -)+N2 *(a‘1Σu -) +ΔE 1 →N2 +N2 +2hν+ΔE 2 and N3 ++e-→N*(2D)+N2(1Σg +)+ΔE 3→N(4S)+N2(1Σg +)+h γ+ΔE 3 are shown to be the basis of defect production and anomalous low-temperature post-desorption ALTpD. The part played by pre-existing and radiation-induced defects in energy storage is discussed.

  16. Defect creation via dissociative recombination of ionic centers in solid Ne matrices

    Energy Technology Data Exchange (ETDEWEB)

    Savchenko, E.V.; Khyzhniy, I.V.; Uyutnov, S.A.; Bludov, M.A. [Institute for Low Temperature Physics and Engineering NASU, 61103 Kharkov (Ukraine); Gumenchuk, G.B.; Bondybey, V.E. [Lehrstuhl für Physikalische Chemie II TUM, 85747 Garching (Germany)

    2016-05-01

    Recombination of the intrinsic ionic centers Ne{sub 2}{sup +} (self-trapped holes) with the detrapped electrons in solid Ne matrices and relaxation channels have been studied. The experiments were performed employing combination of the cathodoluminescence (CL) with current and optical activation spectroscopy techniques. CL spectra were recorded simultaneously in the VUV and visible range. Yields of spectrally resolved thermally and photon-stimulated luminescence (TSL, PSL) and thermally and photon-stimulated exoelectron emission (TSEE, PSEE) were measured in the time-correlated manner. It was found that the recombination reaction proceeds with irreversible dissociation of the transient Ne{sub 2}{sup ∗∗} centers and the dissociative recombination (DR) products exit the matrix cage. Products of the DR reaction are found to be in 3s and 3p states. The detection of “defect” components in the TSL and PSL points to the defect formation via DR in Ne matrices. The temperature range of the electron traps stability is elucidated. A long-lasting “afteremission” of electrons and afterglow of VUV photons observed on switching off the irradiation suggest the accumulation of the uncompensated negative charge.

  17. Photoinduced Effect in -Alumina: Characterization by TSEE Method

    Science.gov (United States)

    Iacconi, P.; Lapraz, D.; Bindi, R.; Benabdesselam, M.

    1997-10-01

    A study of Thermally Stimulated Exoelectron Emission (TSEE) obtained from -alumina samples after X-ray irradiation at 300 K followed by UV excitation at 77 K is reported. The observed results, called photoinduced TSEE (PITSEE) are compared with similar phenomena occurring in thermoluminescence (PITL) and thermally stimulated conductivity (PITSC). Under these conditions, two peaks at about 225 and 270 K are regenerated. The process of regeneration is described in terms of hole transfer and a two-centre Auger mechanism. Lorsque un échantillon d'alumine α est d'abord irradié par rayons X à température ambiante puis refroidi à 77 K et excité par rayons UV, on observe la régénération des pics d'EETS à 225 et 270 K. Ce phénomène, appelé émission exoélectronique thermostimulée photoinduite (PIEETS), est caractérisé et comparé aux phénoménes de thermoluminescence photoinduite (PITL) et de conductivité électrique thermostimulée (PICTS) également présentés par l'alumine α. Le processus de régénération est interprété par un mécanisme de transfert de trous et de transfert d'énergie du type Auger.

  18. Measurement of dose equivalent with personal dosemeters and instrumentation of radiological protection in the new operative magnitudes ICRU, for external fields of radiation beta. Part IV. Survey of the angular response of instruments used in radiological protection in secondary patron fields of beta radiation ({sup 90}Sr/{sup 90}Y (1850 MBq and 74 MBq), {sup 204}TI (18.5 MBq) and {sup 147}Pm (518 MBq)); Medicion de dosis equivalente con dosimetros personales e instrumentacion de proteccion radiologica en las nuevas magnitudes operativas ICRU, para campos de radiacion beta externos. Parte IV. Estudio de la respuesta angular de instrumentos empleados en proteccion radiologica en campos patrones secundarios de radiacion beta ({sup 90}Sr/{sup 90}Y (1850 MBq y 74 MBq), {sup 204}TI (18.5 MBq) y {sup 147}Pm(518 MBq))

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1994-02-15

    Tests type were made (type test) in the following commercial instrumentation commonly used in radiological protection: Geiger-Mueller Counters (FH40 FE), Plastic Scintillators (NE-BP/6/4A), Ionization Chambers (RO-5) and Proportional Counters (HP-100A; gas:P-10). With object of checking the possibility that these they can carry out the new operative unit ICRU, H' (0.07; {alpha}). The tests consisted on determining the energy and angular response of the detectors in secondary patron fields of beta radiation, for isotopes of {sup 90}Sr/{sup 90}Y (1850 MBq and 74 MBq and {sup 147}Pm(518 MBq). The results show the inadequate of these commercial instruments for the realization of the H' operative unit (0.07; {alpha}) in beta external fields. Due to flaws in the design, construction and calibration of the instruments for this type of radiation fields (Author)

  19. Dose received by occupationally exposed workers at a nuclear medicine department

    Energy Technology Data Exchange (ETDEWEB)

    Avila, O.; Sanchez-Uribe, N. A.; Rodriguez-Laguna, A.; Medina, L. A.; Estrada, E.; Buenfil, A. E.; Brandan, M. E. [Instituto Nacional de Investigaciones Nucleares, AP 18-1027, 11801, DF (Mexico); Instituto Nacional de Investigaciones Nucleares, AP 18-1027, 11801, DF (Mexico) and Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, AP 70-542, 04510, DF (Mexico); Instituto Nacional de Cancerologia (INCan), Av. San Fernando No.22, C.P. 14080 (Mexico); Instituto de Fisica, Universidad Nacional Autonoma de Mexico, AP 20-364, 01000 DF (Mexico) and Unidad de Investigacion Biomedica en Cancer INCan-UNAM, Av. San Fernando No.22 C.P. 4080 (Mexico); Instituto Nacional de Cancerologia (INCan), Av. San Fernando No.22, C.P. 14080 (Mexico); Instituto de Fisica, Universidad Nacional Autonoma de Mexico, AP 20-364, 01000 DF (Mexico)

    2012-10-23

    Personal Dose Equivalent (PDE) values were determined for occupational exposed workers (OEW) at the Nuclear Medicine Department (NMD) of 'Instituto Nacional de Cancerologia' (INCan), Mexico, using TLD-100 thermoluminescent dosemeters. OEW at NMD, INCan make use of radiopharmaceuticals for diagnosis and treatment of diseases. Radionuclides associated to a pharmaceutical compound used at this Department are {sup 131}I, {sup 18}F, {sup 68}Ga, {sup 99m}Tc, {sup 111}In and {sup 11}C with main gamma emission energies between 140 and 511 keV. Dosemeter calibration was performed at the metrology department of 'Instituto Nacional de Investigaciones Nucleares' (ININ), Mexico. Every occupational worker used dark containers with three dosimeters which were replaced monthly for a total of 5 periods. Additionally, control dosemeters were also placed at a site free of radioactive sources in order to determine the background radiation. Results were adjusted to find PDE/day and estimating annual PDE values in the range between 2 mSv (background) and 9 mSv. The mean annual value is 3.51 mSv and the standard deviation SD is 0.78 mSv. Four of the 16 OEW received annual doses higher than the average +1 SD (4.29 mSv). Results depend on OEW daily activities and were consistent for each OEW for the 5 studied periods as well as with PDE values reported by the firm that performs the monthly service. All obtained values are well within the established annual OEW dose limit stated in the {sup R}eglamento General de Seguridad Radiologica{sup ,} Mexico (50 mSv), as well as within the lower limit recommended by the 'International Commission on Radiation Protection' (ICRP), report no.60 (20 mSv). These results verify the adequate compliance of the NMD at INCan, Mexico with the norms given by the national regulatory commission.

  20. Statistics of official personal dosimetry and monitoring activities of the period 1994-1995; Statistische Ergebnisse aus der amtlichen Personendosisueberwachung 1994-1995

    Energy Technology Data Exchange (ETDEWEB)

    Boerner, E.; Wittmann, A.; Wahl, W. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz

    1998-12-31

    The measuring laboratory of the GSF in Neuherberg is the largest of the six official supervisory laboratories in Germany. It distributes the officially approved personal dosemeters and is responsible for personal dosimetry monitoring of about 140,000 persons in the German federal states of Bavaria, Hesse, Schleswig-Holstein, and, since 1989, Baden-Wuerttmeberg. Dosemeter readouts are recorded here in a database together with personal data and data describing activities, so that the information collected can be used as a source of reference for establishing general surveys of occupational exposure to external irradition with ionizing radiation. The report first describes the dosemeter designs and the methods applied by the GSF lab for quality assurance, then explains results of the statistical evaluation of the recent data from 1994-1995, and concludes with explaining tendencies shown by long-term curves of the collective and average annual doses recorded in the years from 1986 until 1995. (orig./CB) [Deutsch] Die nach Landesrecht zustaendigen Messstellen haben zur Messung der Personendosis nach Paragraph 63 der Strahlenschutzverordnung und Paragraph 35 der Roentgenverordnung an beruflich strahlenexponierten Personen amtliche Personendosimeter auszugeben und auszuwerten. Die Messstelle der GSF in Neuherberg ist die groesste der 6 offiziellen Messstellen der Bundesrepublik Deutschland. Hier werden rund 140 000 Personen aus den Bundeslaendern Bayern, Hessen, Schleswig-Holstein und seit 1989 Baden-Wuerttemberg ueberwacht. Die Auswertungsergebnisse werden zusammen mit den Personen- und Betriebsdaten in einer Datenbank abgelegt, die es ermoeglicht, allgemeine Aussagen ueber die Strahlenbelastung bei beruflicher Exposition durch externe Bestrahlung zu machen. In diesem Bericht werden zuerst die von der GSF eingesetzten Dosimeter und Methoden der Qualitaetssicherung beschrieben, dann Ergebnisse der statistischen Auswertung des neuen Datenmaterials fuer 1994-95 dargestellt

  1. The use of an electronic portal imaging device for exit dosimetry and quality control measurements.

    Science.gov (United States)

    Kirby, M C; Williams, P C

    1995-02-01

    To determine ways in which electronic portal imaging devices (EPIDs) could be used to (a) measure exit doses for external beam radiotherapy and (b) perform quality control checks on linear accelerators. When imaging, our fluoroscopic EPID adjusts the gain, offset, and frame acquisition time of the charge coupled device (CCD) camera automatically, to allow for the range of photon transmissions through the patient, and to optimize the signal-to-noise ratio. However, our EPID can be programmed to act as an integrating dosemeter. EPID dosemeter measurements were made for 20 MV photons, for different field sizes and thicknesses of unit density phantom material placed at varying exit surface to detector distances. These were compared with simultaneous Silicon diode exit dose measurements. Our exit dosimetry technique was verified using an anthropomorphic type phantom, and some initial measurements have been made for patients treated with irregularly shaped 20 MV x-ray fields. In this dosimetry mode, our EPID was also used to measure certain quality control parameters, x-ray field flatness, and the verification of segmented intensity modulated field prescriptions. Configured for dosimetry, our EPID exhibited a highly linear response, capable of resolving individual monitor units. Exit doses could be measured to within about 3% of that measured using Silicon diodes. Field flatness was determined to within 1.5% of Farmer dosemeter measurements. Segmented intensity modulated fields can be easily verified. Our EPID has the versatility to assess a range of parameters pertinent to the delivery of high quality, high precision radiotherapy. When configured appropriately, it can measure exit doses in vivo, with reasonable accuracy, perform certain quick quality control checks, and analyze segmented intensity modulated treatment fields.

  2. Dose received by occupationally exposed workers at a nuclear medicine department

    Science.gov (United States)

    Ávila, O.; Sánchez-Uribe, N. A.; Rodríguez-Laguna, A.; Medina, L. A.; Estrada, E.; Buenfil, A. E.; Brandan, M. E.

    2012-10-01

    Personal Dose Equivalent (PDE) values were determined for occupational exposed workers (OEW) at the Nuclear Medicine Department (NMD) of "Instituto Nacional de Cancerología" (INCan), Mexico, using TLD-100 thermoluminescent dosemeters. OEW at NMD, INCan make use of radiopharmaceuticals for diagnosis and treatment of diseases. Radionuclides associated to a pharmaceutical compound used at this Department are 131I, 18F, 68Ga, 99mTc, 111In and 11C with main gamma emission energies between 140 and 511 keV. Dosemeter calibration was performed at the metrology department of "Instituto Nacional de Investigaciones Nucleares" (ININ), Mexico. Every occupational worker used dark containers with three dosimeters which were replaced monthly for a total of 5 periods. Additionally, control dosemeters were also placed at a site free of radioactive sources in order to determine the background radiation. Results were adjusted to find PDE/day and estimating annual PDE values in the range between 2 mSv (background) and 9 mSv. The mean annual value is 3.51 mSv and the standard deviation SD is 0.78 mSv. Four of the 16 OEW received annual doses higher than the average +1 SD (4.29 mSv). Results depend on OEW daily activities and were consistent for each OEW for the 5 studied periods as well as with PDE values reported by the firm that performs the monthly service. All obtained values are well within the established annual OEW dose limit stated in the "Reglamento General de Seguridad Radiológica", México (50 mSv), as well as within the lower limit recommended by the "International Commission on Radiation Protection" (ICRP), report no.60 (20 mSv). These results verify the adequate compliance of the NMD at INCan, Mexico with the norms given by the national regulatory commission.

  3. Evaluation of the enter surface dose, dose in organ and E effective dose, received by personnel and patients in studies of endoscopic retrograde cholangeopancreatography in the General Hospital of Mexico; Evaluacion de la dosis de entrada superficie, dosis en organo y dosis efectiva E, recibidas por personal y pacientes en estudios de colangiopancreatografia retrograda endoscopica en el Hospital General de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, S.; Gama T, G. [Calidad XXI SA de CV, Zacatecas 67-007 Col. Roma, 06700 Mexico D.F. (Mexico); Beristain, M.; Espino, H. [Hospital General de Mexico, Dr. Balmis 148, Col. Doctores, 06726 Mexico D.F. (Mexico)]. e-mail: cxxi@prodigy.net.mx

    2006-07-01

    The ESD for patient and personal is measured: gastroenterologuist endoscopist G1, A1 Assistant and A2 instrumentist that carried out 22 independent therapeutic procedures of CPRE, in a fluoroscopy equipment Toshiba trademark with tube under the table, operated in automatic exposure mode, CAE to average tensions of 80 kVp. The measurement is carried out with film dosemeters of double emulsion Kodak Type 2 trademark, calibrated in terms of H{sup *} for the energy of the {sup 137} Cs, first it is determined the films sensitivity like function of the optical density DO, and second the ESD for the effective energy of the radiation beam (50 keV), in three different points from the dosemeter (C, D and H). The films was placed for the personnel in: right hand, front (eye), thyroid and thorax (under D and out F of the lead apron); in the case of the patient three positions were used: thorax, hepatic region and pelvis. The mean values of the ESD and it standard deviation SD in mGy units are determined by: study, personnel, film position in doctor and patient, dosemeter measurement point. The calculated doses in organ are also determined for the patient in the thorax region, liverwort and pelvis its are agreement with the NRPB SR 262 report. Finally the H{sub E} and E for medical personnel and patients are estimated demonstrating that its are not exceeded the annual dose limits for the case of the OEP. In the case of the the OEP have for the D thorax an ESD{sub max} = 0.04 mGy that one corresponds an H{sub E} = 0.02 and E = 0.01 mSv. (Author)

  4. Improvements in the Tl dosimetry for Radiotherapy; Mejoras en la dosimetria Tl para Radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Bustos, S.; Velez, G.; Rubio, M. [CEPROCOR. Arenales 230 Juniors Cordoba 5000 (Argentina)

    1998-12-31

    The thermoluminescent dosimetry (TLD) in vivo has been demonstrated to be one of the most reliable for the control of radiotherapeutic treatments, but the delay in the response is the main disadvantage in its applicability. In this work are presented important improvements and it is demonstrated that maintaining the accuracy and reliability of the technique, it is possible to accelerate the response times at a few hours. To realize this work is utilized a lecturer Harshaw 4000, dosemeters LiF-TLD-100 chips (3.1 x 3.1 x 0.89 mm{sup 3}) and rods (1 x 1 x 6 mm{sup 3}). With the implementation of a glow curve analysis program developed in CIEMAT, its obtained a Tl peaks separation in such manner rapid and accurate, by that the thermal treatment of dosemeters may be reduced at one unique annealing pre-irradiation for 1 hr at 400 Centigrade. It is realized a periodical and individual calibration of the TLD and a study of the factors which influencing the ratio Tl signal-dose as linearity, correction by energy, directional response and pride of Tl signal. the results of this study are introducing in a calculation list specially designed and which allows to obtain absorbed dose by TLD starting of the dates (dosimetric peaks area) which appear of the glow curves analysis. The dose is obtained with an accuracy less than 5 %. The dosemeters already irradiated (in vivo) are analysed and informed in only four hours, allowing a greater control of the treatment and a correction of the possible errors for the next session, still in bi fractional treatments. The method implemented results thus accurate, rapid and reliable. (Author)

  5. Thermoluminescent dosimetry in dentistry students in radiological training; Dosimetria termo-luminiscente en estudiantes de odontologia en entrenamiento radiologico

    Energy Technology Data Exchange (ETDEWEB)

    Loya, M.; Duarte, R. [Escuela de Odontologia, Universidad Autonoma de Chihuahua (Mexico); Montero, M.E. [CIMAV, Chihuahua (Mexico); Gonzalez, P.R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Ojeda, S.L.; Sanin, L.H. [Facultad de Enfermeria y Nutriologia, Chihuahua (Mexico)

    2007-07-01

    Full text: In this work, the obtained results of the mensuration of the equivalent one are presented of dose (E), in students of the career of Dentistry who during their training in radiology complete the three lists of patient, odontologist and observer. The study one carries out with 35 students (Odontologists), 7 men and 28 women, with ages between 20 and 24 years. A characterization of risk was made following the methodology of the Agency for the environmental control of United States (EPA), counting the number of shots in each list, during the time of training. The effective energy of the X rays used was of 24 KeV. The irradiation technique understood two modalities; the first one with 3 shots of 1.25 seconds and the second with 5 shots of 0.6 seconds. The measurement of E, was carried out with thermoluminescent dosemeters (TL) of LiF:Mg,Cu,P+PTFE, developed in the National Institute of Nuclear Research (ININ). The homogenization of the dosemeters showed a variation in its response to the radiation of 1.85%DS. For the odontologist position, the dosemeters was placed to the height of the chest and the measurement was multiplied by the number of shots that it was 304. The E value was of 3.62 mSv/four-month (11 mSv/year), without any safety equipment and of 2.02 mSv/four-month (6.14 mSv/year), when was considered the scenario for this position with use of vest and lead collar, like safety equipment, diminishing E, almost 50%. In the case of the corresponding position to patient, E, it was measured in different organs of interest, the obtained results are compared with the international standards. Recommendations are given for similar cases. (Author)

  6. Stimulated luminescence of AlN ceramics induced by ultraviolet radiation

    DEFF Research Database (Denmark)

    Trinkler, L.; Bøtter-Jensen, L.; Christensen, P.

    2001-01-01

    Properties of thermally stimulated luminescence (TL) and optically stimulated luminescence (OSL) of the ceramic material A1N-Y2O3 have been studied after exposure to ultraviolet radiation (UVR). The dosemeter material Al2O3 : C has been used for comparative measurements. The spectral sensitivity...... than that of Al2O3 : C in a broad spectral region. The possibility of using A1N-Y2O3 ceramic for UVR dosimetry is discussed. (C) 2001 Elsevier Science Ltd. All rights reserved....

  7. Neutron field characterisation at mixed oxide fuel plant.

    Science.gov (United States)

    Passmore, C; Million, M; Kirr, M; Bartz, J; Akselrod, M S; Devita, A; Berard, J

    2012-06-01

    A neutron field characterisation was conducted at the AREVA Melox Plant to determine the response of passive and active neutron dosemeters for several stages in the mixed oxide fuel manufacturing process. Landauer Europe provides radiation dosimetry to many contractors working at the Melox site. The studies were conducted to assist in determining the neutron radiation fields the workers are exposed to routinely, evaluate the need for specific neutron correction factors and to ensure that the most accurate neutron dose is reported for the Melox Plant workers.

  8. DRDC Ottawa Working Standard for Biological Dosimetry

    Science.gov (United States)

    2005-07-01

    sécurité du laboratoire; 3. les sources d’étalonnage et les gammes de doses d’étalonnage utilisées pour établir les courbes de référence permettant...a scanning water tank. The output of the treatment machine was calibrated using a Farmer chamber and electrometer calibrated by the Institute for...chamber (Scanditronix model 8305, S/N 2100, connected to a Farmer Dosemeter 2570/1, S/N 472) was placed in a Vacutainer® tube containing water to

  9. The utilization of bubble detector technology in the development of a Combination Area Neutron Spectrometer (CANS)

    Science.gov (United States)

    Buckner, M. A.; Sims, C. S.

    The compact and relatively inexpensive Combination Area Neutron Spectrometer (CANS) should provide neutron spectral capabilities heretofore available only via complex set-ups and time-consuming, painstaking calculations. Some of its strong points include the measurement of neutron fluence and the need for only a single algorithm, with a single solution, regardless of the spectra. Because fluence, a real quantity, is the foundation of dose equivalent determination, the results of CANS should endure the winds of change accompanying the definition of dose equivalent and its consorted conversion conventions. It is also hoped that personnel applications may be realized in miniature version of CANS, the Personal Neutron Dosemeter/Spectrometer (PENDOSE).

  10. Dose levels in conventional X-rays; Niveles de dosis en radiografia convencional

    Energy Technology Data Exchange (ETDEWEB)

    Guerra M, J. A.; Gonzalez G, J. A.; Pinedo S, A.; Salas L, M. A.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, IPN, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Azorin N, J. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)], e-mail: rgg_df@hotmail.com

    2009-10-15

    There were a series of measures in the General Hospital of Fresnillo in the X-ray Department in the areas of X-1 and X-2-ray rooms and in the neonatal intensive care unit 2, was determined the dose surface entry in eyes, thyroid and gonads for patients undergoing to X-ray study of chest Tele by thermoluminescent dosimetry. Five dosemeters were used in each one of the scans; so find the following dose ranges 20 +{sub -} 23 mGy to 350 +{sub -} 41 mGy. With the results obtained we can conclude that the procedures used and the equipment calibration is adequate. (Author)

  11. Dosimetry of the Occupational Exposure Personnel and not exposure of the INNSZ; Dosimetria del Personal Ocupacionalmente Expuesto (POE) y no expuesto del INNSZ

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz J, A. [Departamento de Medicina Nuclear, Instituto nacional de la nutricion Salvador Zubiran, Mexico D.F. C.P. 14100 (Mexico)

    1999-07-01

    In this work, was measured the equivalent dose of all the personnel of Nuclear medicine and personnel of the Institute which by its activities remain in the Department, by time determined, through thermoluminescent dosemeters and the results were that the personnel presents variable equivalent dose and it is proportional to the time and radionuclide type which use for their work. By this it is allowed to secure what the work watched with respect to radiological protection to fulfil with the International Standards standing for personnel in the Institute. (Author)

  12. Natural gamma radioactivity in the villages of Kanyakumari District, Tamil Nadu, India.

    Science.gov (United States)

    Padua, Jeni Chandar; Basil Rose, M R

    2013-01-01

    In situ radiometric survey carried out in 81 revenue villages of Kanyakumari District, Tamil Nadu, India, using a portable radiation dosemeter/detector, revealed the existence of radiation hotspots along the coastal belt. A close observation of the coastal villages specifically revealed high background radioactivity in 14 coastal villages. A very high intrinsic anomalous radioactivity of 41.03 μSv h(-1) was observed, in a famous tourist spot in the coastal belt of Kanyakumari District. This is the highest level of radiation registered in South India, which is extremely higher than the permissible world average and is suggestive of causing severe clinical problems on continuous and prolonged exposure.

  13. TL Dosimetry on the Tandetron Ion Accelerator area of the ININ; Dosimetria TL en el area del Acelerador de iones Tandetron del ININ

    Energy Technology Data Exchange (ETDEWEB)

    Valdovinos A, M.A.; Gonzalez M, P.R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    For the fulfilment of the operation tests of the Positive Ions type Tandetron 4120 MC, 2 MV, it was obtained the permission consented by the National Commission of Nuclear safety and safeguards (CNSNS). During the stage of tests were arranged Tl dosemeters in the Tandetron Accelerator area, as well as toward to the beam exit. In this work, it was presented the results obtained of the measurement of radiation levels, as much in the area as in the beam exit. This Accelerator is useful in different fields of science such as: biology, radiochemistry, materials, solid state physics, archaeology and environmental sciences between others. (Author)

  14. X-ray dosimetry of low energy using ZrO{sub 2} in Mammography; Dosimetria de rayos X de baja energia usando ZrO{sub 2} en mastografia

    Energy Technology Data Exchange (ETDEWEB)

    Palacios P, L.L.; Rivera M, T.; Ortiz C, H.; Guzman, G. [CICATA, IPN, Av. Legaria 694, 11500 Mexico D.F. (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico); Garcia H, M. [IIM, UNAM, 04510 Mexico D.F. (Mexico)

    2008-07-01

    This work reports the experimental results of the thermoluminescent dosemeters (DTL) of nano particles of zirconium dioxide (ZrO{sub 2}), prepared by the precipitation for X rays method of low energy that are used in mammography equipment. It is observed that the response of the TL curve for X rays of low energy coincides with the TL curve of ZrO{sub 2} reported for conventional X rays. This curve presents two peaks, at 160 and 270 C respectively, being that of more intensity the second peak. (Author)

  15. On the relationship between luminescence excitation spectra and feldspar mineralogy

    DEFF Research Database (Denmark)

    Poolton, N.R.J.; Bøtter-Jensen, L.; Johnsen, O.

    1996-01-01

    Feldspar minerals can be used as naturally occurring radiation dosemeters, with dose assessment commonly using luminescence techniques. Since many feldspars contain radioactive K-40, knowledge of the mineralogy of the luminescent samples being measured is of high importance. Most feldspars contain...... more than trace amounts of highly luminescent Fe3+ impurities, and this article examines the relationship between features of the luminescence excitation spectrum of this ion with sample mineralogy. It is demonstrated that there is a near linear correspondence between the plagioclase feldspar...

  16. Chromosomal analysis and application of biological dosimetry in two cases of apparent over exposure; Analisis cromosomico y aplicacion de la dosimetria biologica en dos casos de aparente sobreexposicion

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Brena V, M. [Departamento de Biologia, ININ A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The gamma radiation calibration curve of {sup 60} Co is used which was generated in the ININ Laboratory of Biology to calculate the exposure dose of two workers whose dosemeters marked values above of the limit allowed. The analysis indicates that in a first case, the aberrations frequency corresponded to the basal value, therefore there is not over exposure. The aberrations frequency of the second case is lightly above to the basal value and therefore the probability favors to what the physical dosimetry indicates. (Author)

  17. Study of the reliability of the TLDs reader in a Thermoluminescent dosimetry laboratory; Estudio de la constancia de la lectora de TLDs en un laboratorio de dosimetria termoluminiscente

    Energy Technology Data Exchange (ETDEWEB)

    Silva F, J.C. da; Fonseca, H.G. da [Instituto de Radioprotecao e Dosimetria-IRD, Av. Salvador Allende s/n- CEP, 22780-160, Rio de Janeiro (Brazil)]. e-mail: Jfeital@ird.gov.br

    2006-07-01

    Acting from the beginning of the decade of 80 in a postal program called 'Dentistry Programs' the Institute of Radioprotection and Dosimetry (IRD) it makes an effort supported by the IAEA so that it can determine with security the reference levels for the diverse practices in radiodiagnostic, including the dentistry. The dentistry program that uses 4 TLDs of lithium fluorite (LiF 100) for evaluations of the doses and of the hemirreductor layer, until 1995 it had already verified close of 5529 X-ray equipment. This work accompanies the result of 3 main parameters (arbitrary reading, reference light and noise) of the reader Harshaw marks 5500, when it is used for routine readings of the TLDs that arrive in the dosimetry laboratory for the due ratings. Together with these TLDs 9 previously selected dosemeters of a certain dosemeters lot is placed with a percentage uncertainty of 3% (for 1 standard deviation). before them they were irradiated in an irradiator of Sr90/Y90 with a dose of approximately 5 mGy, they are treated thermally in an oven PTW it marks to 400 grades for 1 hour + 100 grades for 2 hours and 100 grades in 15 minutes after the irradiations. The referred methodology follows a procedure where they are distributed of 3 in 3 the chosen TLDs of the group of the 9, to the beginning, half and at the end among the total quantity of dosemeters read in the reading disk that it can read of a single time 50 dosemeters. Together with this 10 measurements of reference light and noise are made, data that are provided by the reader through the 'softer WinRem'. Finally the obtained results of reference light and noise, its are compared with the maker's recommendations. Already that of the arbitrary reading (average of the 9 TLDs and its uncertainties), it has revealed a reduction in the percentage uncertainty (2 deviations standard / average) with relationship to one of the first results already obtained through the methodology proposal. It has

  18. Dose for helping persons in the humane medicine, dentistry, and veterinary medicine; Dosis fuer helfende Personen in der Human-, Zahn- und Tiermedizin

    Energy Technology Data Exchange (ETDEWEB)

    Hupe, Oliver [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Arbeitsgruppe ' Photonendosimetrie'

    2013-06-15

    In the framework of a research program sponsored by the Federal Ministry for Environment, Nature Protection, and Reactor Safety and the Federal Office for radiation protection the doses of helping persons in X-ray diagnostics were measured. In the measurement it is to be regarded that the radiation applied in X-ray diagnostics is pulsed for the avoidance of motion uncertainty. Therefore first of all the suitedness of the applied dosemeters for the measurement of pulsed X-radiation had to be tested.

  19. Eurados trial performance test for neutron personal dosimetry

    DEFF Research Database (Denmark)

    Bordy, J.M.; Stadtmann, H.; Ambrosi, P.

    2001-01-01

    This paper reports on the results of a neutron trial performance test sponsored by the European Commission and organised by EURADOS. As anticipated, neutron dosimetry results were very dependent on the dosemeter type and the dose calculation algorithm. Fast neutron fields were generally well...... measured, but particular problems were noted in the determination of intermediate energy fields and large incident angles, demonstrating the difficulties of neutron personal dosimetry. Of particular concern from a radiological protection point of view was the large number of results underestimating...... personal dose equivalent. A considerable over-response was noted in a few cases....

  20. Energy response of graphite-mixed magnesium borate TLDs to low energy x-rays

    DEFF Research Database (Denmark)

    Pelliccioni, M.; Prokic, M.; Esposito, A.

    1991-01-01

    of the energy response to very low energy x-rays are presented and evidence of agreement between experimental and calculated conversion coefficient H'(0.07, alpha = 0-degrees)/Ka is also shown. A monochromatized x-ray beam from a synchrotron radiation source in the energy range from 3 to 12 keV has been......Graphite-mixed sintered magnesium borate TL dosemeters are attractive for beta/gamma dosimetry because they combine a low energy dependence to beta-rays with near tissue or air equivalence to photon irradiations and a high sensitivity. In this paper results from the experimental measurements...

  1. Retrospective dosimetry: Preliminary use of the single aliquot regeneration (SAR) protocol for the measurement of quartz dose in young house bricks

    DEFF Research Database (Denmark)

    Banerjee, D.; Bøtter-Jensen, L.; Murray, A.S.

    1999-01-01

    In retrospective dosimetry, the total dose absorbed by some pre-existing dosemeters, such as house bricks or tiles, is used to derive the dose to the population arising from a nuclear accident. This paper uses the newly developed SAR protocol to determine the total dose in young house bricks from...... the vicinity of the Chernobyl reactor site and from Roskilde, Denmark. For these samples, it is shown that high precision (similar to 1%) on the mean estimates of total dose can be achieved with similar to 20 independent measurements. The SAR total dose estimates of two Danish house bricks agree...

  2. Thermoluminescent characterization of thin films of aluminium oxide submitted to beta and gamma radiation; Caracterizacion termoluminiscente de peliculas delgadas de oxido de aluminio sometidas a radiacion beta y gamma

    Energy Technology Data Exchange (ETDEWEB)

    Villagran, E.; Escobar A, L.; Camps, E.; Gonzalez, P.R.; Martinez A, L. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    By mean of the laser ablation technique, thin films of aluminium oxide have been deposited on kapton substrates. These films present thermoluminescent response (Tl) when they are exposed to beta and gamma radiation. The brilliance curves show two peaks between 112 C and 180 C. A dose-response relationship study was realized and the Tl kinetic parameters were determined using the computerized deconvolution of the brilliance curve (CGCD). The thin films of aluminium oxide have potential applications as ultra.thin radiation dosemeters. (Author)

  3. Personal monitoring services available at Institute for Radiation Protection of ENEA; Il servizo di dosimetria personale dell'Istituto per la Radioprotezione dell'ENEA

    Energy Technology Data Exchange (ETDEWEB)

    Fantuzzi, E.; Bonarelli, T. [ENEA Centro Ricerche Ezio Clementel, Bologna (Italy). Dipt. Ambiente

    1999-07-01

    Personnel monitoring provides the means to measure and record the radiation doses received by individual workers. The ionising radiation decree (230/95) set out the circumstances when the assessment and recording of person's exposure is legally required. Many employers issue dosemeters to staff even though there is no legal requirement to do so. This may be part of a quality assurance programme or as a reassurance measure. Dosemeter readings will serve to ensure compliance with legal dose limits and assure the employer that radiation exposure is as low as reasonably achievable. The ENEA (National Agency for New Technology, Energy and the Environment) IRP (Institute for Radiation Protection) individual monitoring service has been running for over 30 years. It offers personnel dosemeters which are based on its expertise and backed up by continual research and development. The report provides details of the dosemeters in use at IRP enable to decide which ones most suit the needs and shows IMS's organisation, customer and communications, dose reports form and administrative items. A short mention of future development will also be given. [Italian] La dosimetria individuale fornisce gli strumenti per misurare e registrare le dosi da radiazioni ionizzanti ricevute dai lavoratori esposti. Il decreto legislativo 230/95 stabilisce le circostanze in cui il monitoraggio individuale e' legalmente richiesto. Molti datori di lavoro forniscono dosimetri individuali anche quando non vi e' una richiesta legale spesso per seguire le regole di un programma di assicurazione di qualita' relativo alla radioprotezione o per ottenere una conferma che il principio ALARA sia soddisfatto. Il servzio di dosimetria personale dell'Istituto per la Radioprotezione dell'ENEA e' attivo da oltre 30 anni e offre dosimetri sviluppati sulla propria esperienza nelle tecniche dosimetriche che vengono continuamente aggiornati e adeguati rispecchiando lo stato dell

  4. The assessment of external photon dose rate in the vicinity of nuclear power stations. An intercomparison of different monitoring systems

    DEFF Research Database (Denmark)

    Thompson, I.M.G.; Bøtter-Jensen, L.; Lauterbach, U.

    1993-01-01

    to a nuclear power station. The responses of each of these detectors to the natural radiation and to the radiation from the power station are given. Estimations by three of the dose rate instruments of the air kerma from all the radiation components are intercompared with the results from three different types...... of thermoluminescence dosemeter. The results clearly demonstrate that accurate estimations of doses in the environment arising from a nuclear facility can only be obtained if the responses of the detectors used to the different radiation components at that location are accurately evaluated. By correcting the measured...

  5. An optically stimulated luminescence study of porcelain related to radiation dosimetry

    DEFF Research Database (Denmark)

    Poolton, N.R.J.; Bøtter-Jensen, L.; Jungner, H.

    1995-01-01

    This article describes the essential features regarding the photo-stimulated luminescence of porcelain: both the main ceramic and glazing materials are studied. In each case, radiation dose dependent signals are observed, superimposed on dose independent luminescence transitions that are both...... Stokes and anti-Stokes shifted in energy. Glazing is shown in some cases to be considerably more sensitive as a radiation dosemeter than the main porcelain ceramic. By comparison with the properties of artifical phosphors, the principal luminescent matrix is identified as being Al2O3...

  6. Radiation protection in transference of radioactive wastes among buildings of an intermediary deposit; Radioprotecao na transferencia de rejeitos radioativos entre edificios de um deposito intermediario

    Energy Technology Data Exchange (ETDEWEB)

    Mitake, Malvina Boni; Suzuki, Fabio Fumio, E-mail: mbmitake@ipen.b, E-mail: ffsuzuki@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/-CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Radioprotecao

    2011-10-26

    This paper describes the planning of radioprotection realized for transfer operation of radioactive wastes from two old buildings for a one of the new buildings. For planning purposes the operation was divided into nine stages and, for evaluation of collective dose, it was considered various relevant factors. The result of radioprotection optimization it was expected a total collective dose of 58.6 mSv per person. The measured dose per dosemeter of direct reading was of 3.9 mSv per person. These difference among the values is due to conservative factors used in the calculation

  7. Dose on the entrance surface of thyroid, crystalline lens and gonads during the chest X-rays studies; Dosis en la superficie de entrada de tiroides, cristalino y gonadas durante los examenes radiologicos de torax

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez G, R.; Guerra M, J. A.; Pinedo S, A.; Hernandez O, M.; Duran M, H. A.; Salas L, M. A.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98000 Zacatecas (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, IPN, Av. Legaria No. 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Azorin N, J. [Universidad Autonoma Metropolita, Unidad Iztapalapa, Av. San Rafael Atlixco 186, 09340 Mexico D. F. (Mexico)], e-mail: rgg_df@hotmail.com

    2009-10-15

    There were a measurement series in General Hospital of Fresnillo in X-rays department in areas of X-1 and X-2 ray rooms and in a neonatal intensive care unit 2, the dose was determined on the entrance surface into eyes, thyroid and gonads for patients undergoing to X-rays study of tele chest by thermoluminescent dosimetry. 5 dosemeters were used in each of the scans, found the following dose ranges 20+{sub -} 23 {mu}Gy to 350 +{sub -} 41 {mu}Gy. With results we can conclude that the used procedures and the calibration equipment are adequate. (Author)

  8. In vivo dose verification method in catheter based high dose rate brachytherapy.

    Science.gov (United States)

    Jaselskė, Evelina; Adlienė, Diana; Rudžianskas, Viktoras; Urbonavičius, Benas Gabrielis; Inčiūra, Arturas

    2017-12-01

    In vivo dosimetry is a powerful tool for dose verification in radiotherapy. Its application in high dose rate (HDR) brachytherapy is usually limited to the estimation of gross errors, due to inability of the dosimetry system/ method to record non-uniform dose distribution in steep dose gradient fields close to the radioactive source. In vivo dose verification in interstitial catheter based HDR brachytherapy is crucial since the treatment is performed inserting radioactive source at the certain positions within the catheters that are pre-implanted into the tumour. We propose in vivo dose verification method for this type of brachytherapy treatment which is based on the comparison between experimentally measured and theoretical dose values calculated at well-defined locations corresponding dosemeter positions in the catheter. Dose measurements were performed using TLD 100-H rods (6 mm long, 1 mm diameter) inserted in a certain sequences into additionally pre-implanted dosimetry catheter. The adjustment of dosemeter positioning in the catheter was performed using reconstructed CT scans of patient with pre-implanted catheters. Doses to three Head&Neck and one Breast cancer patient have been measured during several randomly selected treatment fractions. It was found that the average experimental dose error varied from 4.02% to 12.93% during independent in vivo dosimetry control measurements for selected Head&Neck cancer patients and from 7.17% to 8.63% - for Breast cancer patient. Average experimental dose error was below the AAPM recommended margin of 20% and did not exceed the measurement uncertainty of 17.87% estimated for this type of dosemeters. Tendency of slightly increasing average dose error was observed in every following treatment fraction of the same patient. It was linked to the changes of theoretically estimated dosemeter positions due to the possible patient's organ movement between different treatment fractions, since catheter reconstruction was

  9. Alanine-EPR dosimetry for measurements of ionizing radiation absorbed doses in the range 0.5-10 kGy

    CERN Document Server

    Peimel-Stuglik, Z

    2001-01-01

    The usefulness of two, easy accessible alanine dosimeters (ALANPOL from IChTJ and foil dosimeter from Gamma Service, Radeberg, Germany) to radiation dose measurement in the range of 0.5-10 kGy, were investigated. In both cases, the result of the test was positive. The foil dosemeter from Gamma Service is recommended for dose distribution measurements in fantoms or products, ALANPOL - for routine measurements. The EPR-alanine method based on the described dosimeters can be successfully used, among others, in the technology of radiation protection of food.

  10. Assessment of the radiological safety of a Genoray portable dental X-ray unit.

    Science.gov (United States)

    Hosseini Pooya, S M; Hafezi, L; Manafi, F; Talaeipour, A R

    2015-01-01

    The portable dental radiographic systems are generally used in emergency situations (e.g. during natural disasters) for disabled/aged patients and in patient rooms. This study assesses the output exposure of a portable dental radiographic system measured using thermoluminescent dosemeters (TLDs). Occupational exposure of the operator was determined when the portable dental unit was used for mandibular and maxillary teeth exposure. The doses of some critical organs of an operator were measured using TLDs implanted within the Rando phantom. Considering the annual organ dose limits, the eye lens dose limit is the main factor determining the frequency of system application.

  11. Using the OSL single-aliquot regenerative-dose protocol with quartz extracted from building materials in retrospective dosimetry

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Solongo, S.; Murray, A.S.

    2000-01-01

    We report on the application of the single-aliquot regenerative-dose (SAR) protocol to the optically stimulated luminescence signal from quartz extracted from fired bricks acid unfired mortar in retrospective dosimetry. The samples came from a radioactive materials storage facility, with ambient...... dose rates of about 0.1 mGy/h. A detailed dose-depth profile was analysed from one brick, and compared with dose records from area TL dosemeters. Small-aliquot dose-distributions were analysed from the mortar samples; one associated with the exposed brick, and one from a remote site exposed only...

  12. Thermal transfer and apparent-dose distributions in poorly bleached mortar samples: Results from single grains and small aliquots of quartz

    DEFF Research Database (Denmark)

    Jain, M.; Thomsen, Kristina Jørkov; Bøtter-Jensen, L.

    2004-01-01

    ;, this process releases all the prior trapped charge and simultaneously sensitises the quartz. Unfortunately unheated materials such as mortar and concrete are more common in industrial sites and particularly in nuclear installations. These materials are usually exposed to daylight during quarrying...... dosimetry. The challenge in using such materials as retrospective dosemeters, is in identifying these well-bleached grains when an accident dose has been superimposed on the original dose distribution. We investigate here, using OSL, the background dose in three different mortar samples: render, whitewash...

  13. Determination of radon levels in Mexico City; Determinacion de niveles de radon en la Ciudad de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Pena G, P

    1992-01-15

    The study of the determination of radon levels in the houses room in Mexico City is part of the project Emanometry of the radon. To carry out this study, the passive method was used, which consists of: thin film dosemeter of cellulose nitrate, container of the same one and spark accountant. The method is based on the mensurations of exhibition of the number of marks of alpha track is of the open type and it allows to average the radon activity along several weeks and it presents low concentrations. This study was carried out in 4 periods of exhibition of 3 months each one. (Author)

  14. Monte Carlo-derived TLD cross-calibration factors for treatment verification and measurement of skin dose in accelerated partial breast irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Garnica-Garza, H M [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional Unidad Monterrey, VIa del Conocimiento 201 Parque de Investigacion e Innovacion Tecnologica, Apodaca NL C.P. 66600 (Mexico)], E-mail: hgarnica@cinvestav.mx

    2009-03-21

    Monte Carlo simulation was employed to calculate the response of TLD-100 chips under irradiation conditions such as those found during accelerated partial breast irradiation with the MammoSite radiation therapy system. The absorbed dose versus radius in the last 0.5 cm of the treated volume was also calculated, employing a resolution of 20 {mu}m, and a function that fits the observed data was determined. Several clinically relevant irradiation conditions were simulated for different combinations of balloon size, balloon-to-surface distance and contents of the contrast solution used to fill the balloon. The thermoluminescent dosemeter (TLD) cross-calibration factors were derived assuming that the calibration of the dosemeters was carried out using a Cobalt 60 beam, and in such a way that they provide a set of parameters that reproduce the function that describes the behavior of the absorbed dose versus radius curve. Such factors may also prove to be useful for those standardized laboratories that provide postal dosimetry services.

  15. Determination of the dose around an ovoid for treatments in intracavitary brachytherapy Hdr; Determinacion de la dosis alrededor de un ovoide para tratamientos en braquiterapia intracavitaria HDR

    Energy Technology Data Exchange (ETDEWEB)

    Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Legaria No. 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Velasco V, R. A. E. [Hospital Central Militar, Periferico y Ejercito Nacional s/n, Lomas de Sotelo, 11200 Mexico D. F. (Mexico); Serrano F, A. K. [Hospital Juarez de Mexico, Av. Instituto Politecnico Nacional No. 5190, Col. Magdalena de las Salinas, 03220 Mexico D. F. (Mexico); Azorin N, J., E-mail: trivera@ipn.m [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco No. 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)

    2010-09-15

    On this work the results of the dosimetric measurements are presented around an ovoid of 2 cm diameter. The measurements were carried out using a water mannequin, an ovoid, a radiation gamma source of {sup 192}Ir and thermoluminescent dosemeters. The dosimetry was realized in the direction of the rectum and bladder. To know the effect of the shielding of the devices type Manchester in the dose, the thermoluminescent dosemeters were irradiated to a radiation gamma source of {sup 192}Ir contained in the Gamma med Plus equipment. The planning was realized normalizing the calculation to 2.5 cm from the applicator center on the transverse plane (2.5, 0, 0). The results show that the dose distribution for an ovoid without shielding is more uniform in the transversal plane to the source axis. The results were compared with the calculated results by means of the planning system BrachyVision. While the absorbed dose distribution around an ovoid with shielding is completely anisotropic. This anisotropic is due to the shielding. (Author)

  16. Use of radiation and radiation practices 1994. Events and statistics

    Energy Technology Data Exchange (ETDEWEB)

    Havukainen, R. [ed.

    1995-05-01

    In Finland, there were 1,745 valid safety licences for the use of radiation at the end of 1994. In addition, 2,050 sites were included in the compulsory registration for dental x-ray diagnostics. The register of the Finnish Centre for Radiation and Nuclear Safety listed 12,794 radiation sources and 316 radionuclide laboratories. The import of radioactive substances amounted to 4.6x10{sup 15} Bq and export to 2.2x10{sup 13} Bq. A total of 1.4x10{sup 13} Bq of short-lived radionuclides were produced in Finland. Workers monitored for radiation exposure included 11,147 employees on 1,294 work sites. Of these, 27% received an annual dose exceeding the recording threshold. The total dose recorded in the dose register (sum of personal dosemeter readings) was 75 man Sv in 1994, nuclear power plant employees accounting for 70% of this total. The annual dosemeter reading of ten medical doctors (radiologists, international radiologists and cardiologists) and five nuclear power plant employees was equal to or in excess of 20 mSv. Effective dose, however, did not exceed the dose limit of 50 mSv established for a one-year monitoring period.

  17. 2010 ATSR prize; Prix ATSR 2010

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2011-07-01

    The article presents the testing of the new dosimetry system operating at the CEA Cadarache center. This system of passive and operational dosimetry is based on 3 dosimeters: PN3+, RPL and EPD-N2. PN3+ is a neutron track detector used for passive dosimetry that can detect fast and thermal neutrons, RPL is a photon passive dosimeter based on radio-photoluminescence, and EPD-N2 is an operational dosimeter detecting neutron and gamma radiations. The comparison of results from passive and operational neutron dosemeters have shown some inconsistencies: some neutron doses recorded by the operational dosimeter do not appear on the PN3+ dosimeter. This study shows that: the detecting threshold of the PN3+ dosimeter is higher than the value given by the manufacturer (100 {mu}Sv), the differences between the values given by PN3+ dosimeters in a series of trials involving either identical equivalent doses or similar neutron spectra and the real values fluctuate in an aleatory manner, and a second reading of some PN3+ dosimeters has shown that the reading stage may be the source of the discrepancies. This study has allowed the calibration of the RPL dosemeter. (A.C.)

  18. Dosimetry in thorax X-rays; Dosimetria en radiografia de torax

    Energy Technology Data Exchange (ETDEWEB)

    Pinedo S, A.; Hernandez O, M.; Duran M, H. A.; Gonzalez G, R.; Guerra M, J. A.; Salas L, M. A.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98000 Zacatecas (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, IPN, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Azorin N, J. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico)], e-mail: lare_56@hotmail.com

    2009-10-15

    The dose to the entrance of thorax during a radiological study has been measured in a phantom of paraffin and with thermoluminescent dosemeters. This work was realized in the living room 1 of the X-rays service of the General Hospital No. 1 IMSS in Zacatecas. For the study thermoluminescent dosemeters of CaSO{sub 4}:Dy were used. The irradiation of the thoracic region is the more studied through the conventional radiology, method that continues occupying the first place as diagnostic in diverse pathologies due to generates images of the heart, lungs, spine, etc. As well as can to observe the location of subclavian catheters, nasogastric sound, endotracheal tubes and umbilical catheters. The magnitude of the dose that is received during the realization of this study type is not usually measured, since the main concern is to have a good image to make a good diagnostic. The measurements were carried out using parameters of the equipment that were defined with base to the experience of the technical radiologist. It was found that the irradiation field is not uniform and that in any point where the dose was measured it is not exceeded the 7 mGy settled by the Mexican Official Standard-157-SSA-1996 for a thorax study. (author)

  19. Dosimetry of industrial sources; Dosimetria de fuentes industriales

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R.; Rodriguez J, R.; Manzanares A, E.; Hernandez V, R.; Ramirez G, J. [Universidad Autonoma de Zacatecas, 98068 Zacatecas (Mexico); Rivera M, T. [CICATA-IPN, 11500 Mexico D.F. (Mexico)]. e-mail: fermineutron@yahoo.com

    2007-07-01

    The gamma rays are produced during the disintegration of the atomic nuclei, its high energy allows them to cross thick materials. The capacity to attenuate a photons beam allows to determine the density, in line, of industrial interest materials as the mining. By means of two active dosemeters and a TLDs group (passive dosimetry) the dose rates of two sources of Cs-137 used for determining in line the density of mining materials were determined. With the dosemeters the dose levels in diverse points inside the grave that it harbors the sources and by means of calculations the isodoses curves were determined. In the phase of calculations was supposed that both sources were punctual and the isodose curves were calculated for two situations: naked sources and in their Pb packings. The dosimetry was carried out around two sources of {sup 137}Cs. The measured values allowed to develop a calculation procedure to obtain the isodoses curves in the grave where the sources are installed. (Author)

  20. Intercomparison of radiation protection devices in a high-energy stray neutron field. Part III: Instrument response

    Energy Technology Data Exchange (ETDEWEB)

    Silari, M., E-mail: marco.silari@cern.c [CERN, 1211 Geneva 23 (Switzerland); Agosteo, S. [Politecnico of Milano, Dipartimento di Energia, piazza Leonardo da Vinci 32, 20133 Milano (Italy); Beck, P. [ARC, Austrian Research Centers GmbH-ARC, 2444 Seibersdorf (Austria); Bedogni, R. [INFN-LNF, Via E. Fermi 40, 00044 Frascati (Italy); Cale, E. [Institut de Radioprotection et Surete Nucleaire, BP 17, 92262 Fontenay aux Roses (France); Caresana, M. [Politecnico of Milano, Dipartimento di Energia, piazza Leonardo da Vinci 32, 20133 Milano (Italy); Domingo, C. [Grup de Fisica de les Radiacions, Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Donadille, L.; Dubourg, N. [Institut de Radioprotection et Surete Nucleaire, BP 17, 92262 Fontenay aux Roses (France); Esposito, A. [INFN-LNF, Via E. Fermi 40, 00044 Frascati (Italy); Fehrenbacher, G. [GSI, Planckstrasse 1, 64291 Darmstadt (Germany); Fernandez, F. [Grup de Fisica de les Radiacions, Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Ferrarini, M. [Politecnico of Milano, Dipartimento di Energia, piazza Leonardo da Vinci 32, 20133 Milano (Italy); Fiechtner, A.; Fuchs, A. [Paul Scherrer Institut, 5232 Villigen (Switzerland); Garcia, M.J. [Grup de Fisica de les Radiacions, Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Golnik, N. [Institute of Atomic Energy, 05-400 Otwock-Swierk (Poland); Gutermuth, F. [GSI, Planckstrasse 1, 64291 Darmstadt (Germany); Khurana, S.; Klages, Th. [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany)

    2009-08-15

    The European Commission has funded within its 6th Framework Programme a three-year project (2005-2007) called CONRAD, COordinated Network for RAdiation Dosimetry. The organizational framework for this project was provided by the European radiation Dosimetry Group EURADOS. Work Package 6 of CONRAD dealt with 'complex mixed radiation fields at workplaces' and in this context it organised a benchmark exercise, which included both measurements and calculations, in a stray radiation field at a high-energy particle accelerator at GSI, Germany. The aim was to intercompare the response of several types of active detectors and passive dosemeters in a well-characterised workplace field. The Monte Carlo simulations of the radiation field and the experimental determination of the neutron spectra with various Bonner Sphere Spectrometers are discussed in Rollet et al. (2008) and in Wiegel et al. (2008). This paper focuses on the intercomparison of the response of the dosemeters in terms of ambient dose equivalent. The paper describes in detail the detectors employed in the experiment, followed by a discussion of the results. A comparison is also made with the H*(10) values predicted by the Monte Carlo simulations and those measured by the BSS systems.

  1. Analysis of the stability of the traps in LiF: Mg, Cu, P by deconvolution of it Tl curve; Analisis de la estabilidad de las trampas en LiF: Mg, Cu, P por deconvolucion de su curva TL

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, P.R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Azorin, J. [UAM-I, San Rafael Atlixco 186, Col Vicentina 09340 Mexico, D.F. (Mexico); Furetta, C. [Universita degli Studi di Roma ' La Sapienza' , Piazzale Aldo Moro 2, 00185, Roma, (Italy); Lopez, J. [Facultad de Matematicas, UADY, s/C.P. Merida, Yucatan (Mexico)

    2004-07-01

    The results of the study of the stability of the traps are presented in Tl dosemeters of LiF: Mg,Cu,P + Ptfe, developed in the ININ, taking like reference to the commercial dosemeter GR200A of Chinese factory. The readings taken Tl the same day of the irradiation they presented four peaks whose energy, determined by deconvolution were; 1.30 {+-} 0.01 eV, 1.50 {+-} 0.01 eV, 1.70 {+-} 0.01 eV and 2.58{+-} 0.02 eV, for LiF: Mg,Cu,P + Ptfe, while for GR200A the energies were: 1.33 {+-} 0.11 eV, 1.58 {+-} 0.11 eV, 1.73 {+-} 0.11 eV and 2.60 {+-} 0.03 eV. The energy of the peaks 3 and 4 that remained visible during six months of study it was: 1.38 {+-} 0.01 eV and 2.65 {+-} 0.01 eV, for LiF: Mg,Cu,P + Ptfe respectively, in the same order for GR200A, the energies were: 1.51 {+-} 0.02 eV and 2.64 {+-} 0.03 eV. (Author)

  2. Quality assurance program in the External dosimetry laboratory of the CPHR; Programa de aseguramiento de la calidad en el laboratorio de dosimetria externa del CPHR

    Energy Technology Data Exchange (ETDEWEB)

    Molina P, D.; Pernas S, R.; Martinez H, E.; Cardenas H, J. [Centro de Proteccion e Higiene de las Radiaciones, Calle 20 No. 4113 e/41 y 47. Playa, C.P. 11300, A.P. 6195, C.P. 10600 La Habana (Cuba)

    2006-07-01

    From 1999 the Laboratory of External Dosimetry of the Radiation Protection and Hygiene Center comes applying in its service of personal dosimetry a Program of Quality Assurance. This program was designed according to the recommendations of national and international organizations as the National Assuring Office of the Republic of Cuba (ONARC), the International Standards Organization (ISO), the International Electro technique Commission (IEC) and the International Atomic Energy Agency (IAEA). In this work it is presented in a summarized way the operation of this Program of Quality Assurance which includes the administration and conservation of the results and the documentation of the service, the controls that are carried out to the equipment, the acceptance tests that are applied to the equipment and new dosemeters, the shipment and prosecution of the dosemeters, the evaluation, storage and conservation of the doses, the report of the results, the traceability and reproducibility of the measurements, the attention to the reclamations and the clients complaints and the internal and external audits to those that it undergoes periodically the laboratory. (Author)

  3. Intercomparison of radiation protection instrumentation in a pulsed neutron field

    Science.gov (United States)

    Caresana, M.; Denker, A.; Esposito, A.; Ferrarini, M.; Golnik, N.; Hohmann, E.; Leuschner, A.; Luszik-Bhadra, M.; Manessi, G.; Mayer, S.; Ott, K.; Röhrich, J.; Silari, M.; Trompier, F.; Volnhals, M.; Wielunski, M.

    2014-02-01

    In the framework of the EURADOS working group 11, an intercomparison of active neutron survey meters was performed in a pulsed neutron field (PNF). The aim of the exercise was to evaluate the performances of various neutron instruments, including commercially available rem-counters, personal dosemeters and instrument prototypes. The measurements took place at the cyclotron of the Helmholtz-Zentrum Berlin für Materialien und Energie GmbH. The cyclotron is routinely used for proton therapy of ocular tumours, but an experimental area is also available. For the therapy the machine accelerates protons to 68 MeV. The interaction of the proton beam with a thick tungsten target produces a neutron field with energy up to about 60 MeV. One interesting feature of the cyclotron is that the beam can be delivered in bursts, with the possibility to modify in a simple and flexible way the burst length and the ion current. Through this possibility one can obtain radiation bursts of variable duration and intensity. All instruments were placed in a reference position and irradiated with neutrons delivered in bursts of different intensity. The analysis of the instrument response as a function of the burst charge (the total electric charge of the protons in the burst shot onto the tungsten target) permitted to assess for each device the dose underestimation due to the time structure of the radiation field. The personal neutron dosemeters were exposed on a standard PMMA slab phantom and the response linearity was evaluated.

  4. RADIATION PROTECTION CABIN FOR CATHETER-DIRECTED LIVER INTERVENTIONS: OPERATOR DOSE ASSESSMENT.

    Science.gov (United States)

    Maleux, Geert; Bergans, Niki; Bosmans, Hilde; Bogaerts, Ria

    2016-09-01

    The number and complexity of interventional radiological procedures and in particular catheter-directed liver interventions have increased substantially. The current study investigates the reduction of personal doses when using a dedicated radiation protection cabin (RPC) for these procedures. Operator and assistant doses were assessed for 3 series of 20 chemoinfusion/chemoembolisation interventions, including an equal number of procedures with and without RPC. Whole body doses, finger doses and doses at the level of knees and eyes were evaluated with different types of TLD-100 Harshaw dosemeters. Dosemeters were also attached on the three walls of the RPC. The operator doses were significantly reduced by the RPC, but also without RPC, the doses appear to be limited as a result of thorough optimisation with existing radiation protection tools. The added value of the RPC should thus be determined by the outcome of balancing dose reduction and other aspects such as ergonomic benefits. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Study of the Li{sub 2}CO{sub 3} as thermal neutrons detector; Estudio del Li{sub 2}CO{sub 3} como detector de neutrones termicos

    Energy Technology Data Exchange (ETDEWEB)

    Herrera A, E.; Urena N, F.; Delfin L, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)] e-mail: eha@nuclear.inin.mx

    2003-07-01

    The use every day but it frequents of the thermal neutrons in the treatment of tumours, using the neutron capture therapy technique in boron, there is generated the necessity to develop a dosimetric system that allows to evaluate in a reliable way the fluence and consequently the dose of neutrons that it is given in the tumours of the patients. One of the techniques but employees to determine the neutron fluence sub cadmic and epi cadmic in an indirect way, it is the activation of thin sheets of gold undress and covered with cadmium respectively that when being exposed to a neutron beam to the nuclear reaction {sup 197}Au (n, {gamma} ) {sup 198} Au, emitting gamma radiation with an energy of 0.4118 MeV, being this, a disadvantage to be used as dosemeter. On the other hand, when exposing the lithium carbonate to a thermal neutron beam, free radicals of CO{sub 3} that are quantified by the electron paramagnetic resonance technique are generated. This work analyzes those basic parameters that determine if those made up of Li{sub 2}CO{sub 3} complete with the requirements to be used as detectors and/or dosemeters of thermal neutrons. (Author)

  6. Development of a technique for improving coefficient of variation of CaSO4:Dy teflon-based TLD personnel monitoring system in low-dose region.

    Science.gov (United States)

    Pradhan, S M; Sneha, C; Sahai, M K; Chougaonkar, M P; Babu, D A R

    2015-12-01

    In view of the importance of zero-dose background (null signal) in influencing the coefficient of variation in low-dose region, a technique for the estimation of the same from composite (gross) signal is developed for CaSO4:Dy-based personnel monitoring system being used in India. The technique is based on simple analysis of glow curves (GCs) of unexposed and exposed dosemeters, evolution of trend/model for the zero-dose curves, generation of simulation protocol for individual zero-dose curves, establishment of characteristics of GCs of exposed dosemeters and finally preparation of an algorithm to segregate the components from composite signal. The technique offers the separation of real-time background and gives superior results over other method of approximation of the background. The results also prove efficiency of the empirical trending and simulation protocol of background GCs. The proposed technique can be implemented in routine monitoring without any extra man hours and reader time. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Neutron measurements in the Vandellòs II nuclear power plant with a Bonner sphere system.

    Science.gov (United States)

    Fernández, F; Bakali, M; Tomás, M; Muller, H; Pochat, J L

    2004-01-01

    In some Spanish nuclear power plants of pressurised water reactor (PWR) type, albedo thermoluminescence dosemeters are used for personal dosimetry while survey meters, based on a thermal-neutron detector inside a cylindrical or spherical moderator, are used for dose rate assessment in routine monitoring. The response of both systems is highly dependent on the energy of the existing neutron fields. They are usually calibrated by means of ISO neutron sources with energy distributions quite different from those encountered at these installations. Spectrometric measurements with a Bonner sphere system (BSS) allow us to determine the reference dosimetric values. The UAB group, under request from the National Coordinated Research Action, was in charge of characterising the neutron fields and evaluating the response of personal dosemeters at several measurement points inside the containment building of the Catalan Nuclear Power Plant Vandellòs II. The neutron fields were characterised at five places using the UAB-BSS and a home made unfolding code called MITOM. The results obtained confirm the presence of low-energy components in the neutron field in most of the selected points. Moreover, we have found no influence of the nuclear fuel burning on the shape of the spectrum.

  8. TL dosimeters for gamma and thermal neutrons used at ENEA. Accuracy and calibration standards; Dosimetri a TL per neutroni termici e gamma impiegati in ENEA: metodo, calibrazione e qualificazione

    Energy Technology Data Exchange (ETDEWEB)

    Fantuzzi, E.; Gualdrini, G.F.; Monteventi, F.; Morelli, B.; Uleri, G. [ENEA, Centro Ricerche Ezio Clementel, Bologna (Italy). Dipt. Ambiente

    1998-07-01

    This work summaries the experimental results achieved on the characterisation of dosimetric systems used at ENEA (National Agency for New Technology, Energy and the Environment) laboratory in Bologna (Italy) and describes the calibration method either for a two-element dosemeter Harshaw and for a two-element dosemeter assembled at ENEA with higher sensitivity LiF detectors. Both calculation algorithm and calibration procedure have been defined and analyzed in terms of the dosimetric reference quantities. In addition, parameters responsible and crucial for the dosimetric reference quantities. In addition, parameters responsible and crucial for the dosimetric results are pointed out. Finally, intercomparisons between experimental data and numerical data (Monte Carlo code) are shown. [Italian] Vengono esposti i metodi utilizzati per la calibrazione di un dosimetro Harshaw e di uno con maggiore sensibilita' prodotto dal centro ENEA di Bologna con LiF. Sono stati definiti sia l'algoritmo di calcolo sia la procedura di calibrazione ed analizzate le problematiche legate alle grandezze di riferimento. Sono state inoltre individuate le specifiche variabili che possono incidere sul dato dosimetrico ed infine esposti i risultati di interconfronti sperimentali e di calcolo con tecnica Monte Carlo.

  9. Measurements of the neutron dose and energy spectrum on the International Space Station during expeditions ISS-16 to ISS-21.

    Science.gov (United States)

    Smith, M B; Akatov, Yu; Andrews, H R; Arkhangelsky, V; Chernykh, I V; Ing, H; Khoshooniy, N; Lewis, B J; Machrafi, R; Nikolaev, I; Romanenko, R Y; Shurshakov, V; Thirsk, R B; Tomi, L

    2013-01-01

    As part of the international Matroshka-R and Radi-N experiments, bubble detectors have been used on board the ISS in order to characterise the neutron dose and the energy spectrum of neutrons. Experiments using bubble dosemeters inside a tissue-equivalent phantom were performed during the ISS-16, ISS-18 and ISS-19 expeditions. During the ISS-20 and ISS-21 missions, the bubble dosemeters were supplemented by a bubble-detector spectrometer, a set of six detectors that was used to determine the neutron energy spectrum at various locations inside the ISS. The temperature-compensated spectrometer set used is the first to be developed specifically for space applications and its development is described in this paper. Results of the dose measurements indicate that the dose received at two different depths inside the phantom is not significantly different, suggesting that bubble detectors worn by a person provide an accurate reading of the dose received inside the body. The energy spectra measured using the spectrometer are in good agreement with previous measurements and do not show a strong dependence on the precise location inside the station. To aid the understanding of the bubble-detector response to charged particles in the space environment, calculations have been performed using a Monte-Carlo code, together with data collected on the ISS. These calculations indicate that charged particles contribute measurements in space.

  10. In vivo Tl dosimetry for the quality control in Radiotherapy with {sup 60} Co and brachytherapy of low dose rate; Dosimetria Tl in vivo para el control de calidad en Radioterapia con {sup 60} Co y Braquiterapia de baja tasa de dosis

    Energy Technology Data Exchange (ETDEWEB)

    Velez, G.; Bustos, S.; Balmaceda, O.; Gutierrez, S.; Ferraris, M. [Servicio de Radioterapia, Hospital San Roque. Rosario de Santa Fe 374. CP 5000. Cordoba (Argentina)

    1998-12-31

    In vivo dosimetry is used every time with more frequency as a valuable tool for the quality control in Radiotherapy. The measurements of input and output doses provide us information about the technique accuracy or the treatment procedure used; likewise the dose measurement which rectum or bladder receive in gynecologic implants contribute to the improving and adjusting the procedures in brachytherapy. Besides, it may be identify systematic errors in particular situations which allow to optimize the treatment and to minimize errors. It was realized a study at the Radiotherapy service in San Roque Hospital (Cordoba) to control the procedures used in the treatment of distinct oncologic pathologies. Its were selected patients, which were realized the routine planning with the planning system of computerized treatments Prowess 3000, that later its were controlled with In vivo thermoluminescent dosimetry using the Ceprocor Services (Cordoba). Its were realized dose skin measurements in treatments of mammary gland, pelvis, thorax, head and neck and it were measured doses in body cavities, as oral cavity, rectum, esophagus, etc. arranging the TLD inside special catheters. In the case of dose skin, the dosemeters were arranged in acrylic porta-dosemeters, at pairs, which later they were enveloped and sealed. It was founded a very good agreement among the In vivo measurements and the predicted by the planner. In some cases, the control allows to modify the treatment for to avoid over or sub dosages of the distinct organs affected by the radiation field. (Author)

  11. TL properties of newly developed lithium tetraborate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, A.C. [Nuclear Physics Centre, Av. Prof. Gama Pinto, 2, 1049 003 Lisbon (Portugal) and Hospital de Santa Maria, Servico de Radioterapia, Av. Prof. Egas Moniz, 1049 035 Lisbon (Portugal); Instituto Politecnico de Leiria, Escola Superior de Tecnologia do Mar, Santuario Na Sra. dos Remedios, 2520 631 Peniche (Portugal)], E-mail: anafer@itn.pt; Osvay, M. [Institute of Isotopes, 1525 Budapest, P.O.B. 77 (Hungary); Santos, J.P. [Nuclear and Technological Institute, Estrada Nacional 10, 2686 953 Sacavem (Portugal); Holovey, V. [Institute of Electron Physics, NASU, 88000 Uzhgorod (Ukraine); Ignatovych, M. [Institute of Surface Chemistry, NASU, 03164 Kyiv (Ukraine)

    2008-02-15

    The thermoluminescent properties of transparent and colorless plates (6x6x1mm) of undoped and Cu-doped lithium tetraborate single crystals produced in the Institute of Electron Physics (Ukraine) were investigated using low and high LET radiations and mixed-radiation fields (photon and thermal neutrons). A comparative characterization of undoped (LTB) and Cu-doped (LTB:Cu) lithium tetraborate single crystals to TLD-100, TLD-700, TLD-700H and Al{sub 2}O{sub 3}:Mg,Y (D-3) dosemeters is also reported. The results show that LTB:Cu is approximately 50 times more sensitive to gamma radiation than LTB and 5 times more sensitive as compared with TLD-100 dosemeters. On the other hand, LTB:Cu is about 5 times less sensitive to thermal neutrons than LTB, which suggests the application of paired LTB and LTB:Cu for mixed-field dosimetry. Both LTB and LTB:Cu single crystals have negligible light sensitivities, which is a major improvement over former lithium tetraborate-based TLDs.

  12. Intercomparison of radiation protection instrumentation in a pulsed neutron field

    Energy Technology Data Exchange (ETDEWEB)

    Caresana, M., E-mail: marco.caresana@polimi.it [Politecnico di Milano, CESNEF, Dipartimento di Energia, via Ponzio 34/3, 20133 Milano (Italy); Denker, A. [Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Esposito, A. [IFNF-LNF, FISMEL, via E. Fermi 40, 00044 Frascati (Italy); Ferrarini, M. [CNAO, Via Privata Campeggi, 27100 Pavia (Italy); Golnik, N. [Institute of Metrology and Biomedical Engineering, Warsaw University of Technology, Sw. A. Boboli 8, 02-525 Warsaw (Poland); Hohmann, E. [Paul Scherrer Institut (PSI), Radiation Metrology Section, CH-5232 Villigen PSI (Switzerland); Leuschner, A. [Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22603 Hamburg (Germany); Luszik-Bhadra, M. [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany); Manessi, G. [CERN, 1211 Geneva 23 (Switzerland); University of Liverpool, Department of Physics, L69 7ZE Liverpool (United Kingdom); Mayer, S. [Paul Scherrer Institut (PSI), Radiation Metrology Section, CH-5232 Villigen PSI (Switzerland); Ott, K. [Helmholtz-Zentrum Berlin, BESSYII, Albert-Einstein-Str.15, 12489 Berlin (Germany); Röhrich, J. [Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Silari, M. [CERN, 1211 Geneva 23 (Switzerland); Trompier, F. [Institute for Radiological Protection and Nuclear Safety, F-92262 Fontenay aux Roses (France); Volnhals, M.; Wielunski, M. [Helmholtz Zentrum München, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany)

    2014-02-11

    In the framework of the EURADOS working group 11, an intercomparison of active neutron survey meters was performed in a pulsed neutron field (PNF). The aim of the exercise was to evaluate the performances of various neutron instruments, including commercially available rem-counters, personal dosemeters and instrument prototypes. The measurements took place at the cyclotron of the Helmholtz-Zentrum Berlin für Materialien und Energie GmbH. The cyclotron is routinely used for proton therapy of ocular tumours, but an experimental area is also available. For the therapy the machine accelerates protons to 68 MeV. The interaction of the proton beam with a thick tungsten target produces a neutron field with energy up to about 60 MeV. One interesting feature of the cyclotron is that the beam can be delivered in bursts, with the possibility to modify in a simple and flexible way the burst length and the ion current. Through this possibility one can obtain radiation bursts of variable duration and intensity. All instruments were placed in a reference position and irradiated with neutrons delivered in bursts of different intensity. The analysis of the instrument response as a function of the burst charge (the total electric charge of the protons in the burst shot onto the tungsten target) permitted to assess for each device the dose underestimation due to the time structure of the radiation field. The personal neutron dosemeters were exposed on a standard PMMA slab phantom and the response linearity was evaluated.

  13. Dose rate constants for the quantity Hp(3) for frequently used radionuclides in nuclear medicine.

    Science.gov (United States)

    Szermerski, Bastian; Bruchmann, Iris; Behrens, Rolf; Geworski, Lilli

    2016-12-01

    According to recent studies, the human eye lens is more sensitive to ionising radiation than previously assumed. Therefore, the dose limit for personnel occupationally exposed to ionising radiation will be lowered from currently 150 mSv to 20 mSv per year. Currently, no data base for a reliable estimation of the dose to the lens of the eye is available for nuclear medicine. Furthermore, the dose is usually not monitored. The aim of this work was to determine dose rate constants for the quantity Hp(3), which is supposed to estimate the dose to the lens of the eye. For this, Hp(3)-dosemeters were fixed to an Alderson Phantom at different positions. The dosemeters were exposed to radiation from nuclides typically used in nuclear medicine in their geometries analog to their application in nuclear medicine, e.g. syringe or vial. The results show that the handling of high-energy beta (i.e. electron or positron) emitters may lead to a relevant dose to the lens of the eye. For low-energy beta emitters and gamma emitters, an exceeding of the lowered dose limit seems to be unlikely. Copyright © 2015. Published by Elsevier GmbH.

  14. Comparative dosimetric study in the estimation of the dose rate of the Transelektro LGI-01 irradiator; Estudio dosimetrico comparativo en la estimacion de la razon de dosis del irradiador Transelektro LGI-01

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco A, H.; Urena N, F.F. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2004-07-01

    The {sup 60} Co TRANSELEKTRO, model LGI-0 1, Hungarian, is similar to the Canadian Gamma cell. The evaluation of the dose ratio in the geometric center of the exposition chamber of the LGI-0 1 is presented in this paper. In order to do this two types of dosimeters were used: the alanine, and the L8-C 1 red acrylic (Canadian). Three dosimeters of each type were irradiated at 1, 2, 3, 4, 5, 6, 7 and 8 h. The respective intensities and absorbencies were measured and used to determine the proper absorbed doses and the dose ratio. The results obtained with both dosimeters were compared with the ratio dose that was reported by the Secondary Laboratory of Dosimetric Calibration of the Metrology Department of the ININ, which used a ionization chamber for the calibration of the LGI-0 1. The alanine dosemeter showed a {+-} 1.3% dispersion while with the acrylic dosemeter the dispersion was of {+-} 3.2%, with respect to the value reported by the authorized Calibration Laboratory. This paper was also used to update the calibration table of the L8-C1 red acrylic. (Author)

  15. Radiation practices 1997

    Energy Technology Data Exchange (ETDEWEB)

    Havukainen, R. [ed.

    1998-05-01

    At the end of 1997, there were 1,753 valid safety licenses in Finland for the use of radiation. In addition, there were 2,065 responsible parties for dental x-ray diagnostics. The registry of STUK - Radiation and Nuclear Safety Authority listed 13,839 radiation sources and 302 radionuclide laboratories. The import of radioactive substances amounted to 1.09 x 10{sup +16} Bq and export to 2.4 x 10{sup +13} Bq. Short-lived radionuclides produced in Finland amounted to 5.2 x 10{sup +13} Bq. There were 11,773 workers monitored for radiation exposure at 1,316 work sites. Of these employees, 24% received an annual dose exceeding the recording level. The total dose recorded in the dose registry (sum of the individual dosemeter readings) was 6.6 Sv in 1997, with nuclear power plant workers accounting for 62% of this total. The annual dosemeter reading of thirteen medical doctors (radiologists, interventional radiologists and cardiologists) and six nuclear power plant employees was equal to or in excess of 20 mSv. Effective doses, however, did not exceed the dose limit of 50 mSv established for one-year monitoring periods. The sum of the dosemeter readings (depth dose) on the lead-rubber apron of one interventional radiologist was 253 mSv. It was verified that the annual dose limit for the lens of the eye, 150 mSv, had been exceeded in this case. This high dose was caused by the fact that the radiologist had carried out multiple examinations in which unusually high exposure to radiation was an unavoidable part of the task. Reports were made of four incidents of anomalies in the use of radiation. None of these proved to have caused significant radiation exposure to the radiation source operators. Two of these cases occurred in the medical use of radiation, one in the use of radiation sources in industry, and one in the use of solarium appliances. (orig.)

  16. Air kerma and absorbed dose on the torso of a patient during a mammography study;Kerma en aire y dosis absorbida en el torso de una paciente durante un estudio mastografico

    Energy Technology Data Exchange (ETDEWEB)

    Hernadez O, M.; Duran M, H. A.; Pinedo S, A.; Gonzalez G, R.; Guerra M, J. A.; Salas L, M. A.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, 11500 Mexico D. F. (Mexico); Azorin N, J., E-mail: mar_h2o@hotmail.co [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, 09340 Mexico D. F. (Mexico)

    2009-10-15

    Two dosimetric magnitudes, due to the dispersed radiation, have been determined during a mammography study. The magnitudes that were determined are the kerma at the entrance of the torso and the absorbed dose by the torso. This determination was made in a paraffin phantom and with thermoluminescent dosemeters. One of the important parameters in the radiological protection of a patient to which is practiced a mammography is the value of the media glandular dose. However, during the taking of the X-ray a radiation portion that impacts on the mammary gland it is dispersed toward the patient's torso. In this work thermoluminescent dosemeters of ZrO{sub 2} has been used to determine the kerma at the entrance of the torso like the absorbed dose. The dosemeters was placed on the surface of the torso phantom while to the mamma phantom was made the mammography. As mamma phantom was used glucose serum to 5%. Of the obtained results we find that 3% of the air kerma at the entrance of the mamma it corresponds at the air kerma that receives the torso and 3.2% of the media glandular dose it is the absorbed dose of the same one. Another important result is the percentage value of the air kerma on the entrance of the thyroid area during a mammography, due to the dispersed radiation, it is 4% of the kerma at the entrance of the mamma. The air kerma at the entrance of the thyroid is of 0.41 +-0.07 mGy, 10% of this value corresponds to the absorbed dose by the thyroid. Therefore, it is observed that the media glandular dose and the air kerma at the entrance of the mamma they influence on the dispersed radiation toward the torso. Also, the superior part of the torso has less attenuation capacity to the dispersed radiation that those located in the inferior part. Therefore, the thyroid receives the major quantity of air kerma at the entrance. (Author)

  17. Analysis of the neutron component and determination of the LET spectrum at high altitudes

    Energy Technology Data Exchange (ETDEWEB)

    Vana, N.; Minarik, M.; Schoener, W. [Atoministitute of the Austrian Universities, Stadionallee 2, A-1020 Vienna (Austria); Berger, T.; Hajek, M.; Noll, M. [Institute for Space Dosimetry, Lustkandlgasse 52/3, A-1090 Vienna (Austria)

    2000-05-01

    The European Council directive 96/29/Euratom of 13 May 1996 emphasizes the introduction of two categories for occupational exposure. Category A includes the employees for whom the annual effective dose is likely to exceed 6 mSv. Suggesting an average flight time between 600 and 1000 hours per year for aircrew, the typical annual dose lies between 4 and 8 mSv with a maximum value of 15 mSv for Concorde flights. This requires the surveillance of aircrew members and thus the development of proper measurement devices. Because of the similar radiation environment, high altitude mountains seem to be an ideal choice to test and to improve recently developed measurement systems. Bonner Sphere Spectrometers (BSS) with a {sup 6}LiI(Eu) scintillation counter and thermoluminescent dosemeters (TLDs), respectively, were used to determine the neutron energy spectrum as well as the absorbed dose and the average linear energy transfer (LET) in a complex mixed radiation field on top of Mt. Sonnblick (3105 m). The neutron component makes up 35 to 60% of the biologically relevant dose at high altitudes, depending on the geomagnetic latitude. The average LET of the mixed radiation field was determined using the high temperature ratio (HTR)-method. Paired TLD-600 and TLD-700 dosemeters as well as an extended range Sievert counter were employed for determination of the neutron dose equivalent. Furthermore, a LET spectrum was recorded on Mt. Kitzsteinhorn (3029 m) using the laboratory-manufactured tissue equivalent proportional counter (TEPC)-system PART. All detectors were calibrated with standard radiation sources and in the CERN EC neutron reference field. The measurements performed with the passive BSS as well as the Sievert counters show that there exists a neutron component with energies up to 100 MeV (and probably more) at such altitudes. The total dose equivalent rate measured on top of Mt. Sonnblick was 200 nSv.h{sup -1} compared to an absorbed dose rate of 120 nGy.h{sup -1}. The

  18. An investigation into the effect of protective devices on the dose to radiosensitive organs in the head and neck

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, N.W.; Faulkner, K. (Newcastle General Hospital (United Kingdom)); Clarke, P. (Royal Victoria Infirmary, Newcastle upon Tyne (United Kingdom))

    1992-09-01

    A series of experiments were performed to determine the dose reduction afforded to radiosensitive organs in the head and neck by various protective devices. These included spectacles with plastic, standard glass, photochromic and lead-glass lenses, a thyroid collar and a lead-acrylic face mask. The measurements were performed using an anthropomorphic phantom loaded with lithium fluoride thermoluminescent dosemeters, in conditions realistic of clinical practice. Irradiations were performed using scattered radiation produced by a pelvic phantom, for X-ray beams generated at 80 kVp and 110 KVp. Also presented is the ratio of organ dose to dose to the bridge of the nose for thyroid, oesophagus, brain and sinuses, as measured for the case of no head or neck protection. (author).

  19. Description of the XXXIV ARCAL Project {sup R}epairing and calibration of electrometers and ionization chambers used in radiotherapy; Descripcion del proyecto ARCAL XXXIV {sup R}eparacion y calibracion de electrometros y camaras de ionizacion utilizados en radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Cruz E, P.; Villaverde L, A. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The technological tools from what the humanity has for the illnesses diagnosis and the cancer treatment, are based in great extent in the use of ionizing radiations. This situation worries to the International Atomic Energy Agency (IAEA), which has implemented technical cooperation programs for protecting the human health. In Latin America the ARCAL program (Regional Agreement of Cooperation for Promotion of Nuclear Science and Technology in Latina America and the Caribbean was created. The Project ARCAL XXXIV has as objective to establish three regional centers of repairing, maintenance and electric calibration of clinical dosemeters, equipment made up for an ionization chamber and an electrometer which is used in radiotherapy to generate calibration procedures, personnel training, establishment of an intercomparison net for the electrometers control used as standards and designing current intensity sources which serve as work standards for each one of the participant countries, Mexico is one of them. (Author)

  20. Dosimetric properties of new cards with high-sensitivity MCP-N (LiF:Mg,Cu,P) detectors for Harshaw automatic reader.

    Science.gov (United States)

    Budzanowski, M; Bilski, P; Olko, P; Ryba, E; Perle, S; Majewski, M

    2007-01-01

    A new configuration for a thermoluminescent dosimetric card has been developed through collaboration between the Institute of Nuclear Physics in Kraków and several commercial dosimetric companies. The card is based on high-sensitivity LiF:Mg,Cu,P circular pellets (MCP-N) welded inside synthetic foils. The basic configuration consists of two pellets of 3.6 mm diameter and thicknesses from 0.25 up to 0.38 mm. The cards can be processed in a standard 6600 or 8800 Harshaw automatic TLD reader. The dosemeters demonstrate very high sensitivity, low background and good stability. This article presents results of the performance tests of the new dosimetric cards in the automatic TLD readers and a comparison of their properties.

  1. THE THERMOLUMINESCENCE EFFICIENCY OF Li(2)B(4)O(7):Cu AND OF CaSO(4):Tm FOR PHOTONS

    CERN Document Server

    Otto, T; Gindraux, L

    2011-01-01

    The intrinsic thermoluminescence (TL) efficiency of a TL detector relates the absorbed dose in the detector material to the light yield observed upon evaluation. Knowledge of the TL efficiency is of interest when performing numerical simulations of detector response, where only absorbed dose can be predicted. Here, the experimental determination of TL efficiency for calcium sulphate (CaSO(4):Tm) and lithium borate (Li(2)B(4)O(7):Cu) is reported. These materials are widely used in Panasonic dosemeter badges. The results of the study are in agreement with predictions from track structure theory and microdosimetry, relating an enhanced light yield at low X-ray energies to supralinear behaviour of the TL phosphor.

  2. History of the solar particle event radiation doses on-board aeroplanes using a semi-empirical model and Concorde measurements

    Energy Technology Data Exchange (ETDEWEB)

    Lantos, P.; Fuller, N

    2003-07-01

    Measurements during solar particle events with dosemeters flying permanently on-board Concorde are used to develop a semi-empirical model, called SiGLE. The model is intended to calculate, for a given flight plan, the dose equivalent received during a solar particle event observed with ground-based neutron monitors. It is successfully in operation in the SIEVERT computerised system intended to improve monitoring of radiation dose received by aircrews, in application to a European Directive. The semi-empirical model is applied to evaluate, for most exposed routes, the radiation doses corresponding to the GLEs observed since 1942 with ion chambers or neutron monitors. The results for the largest GLEs observed in the past are discussed in terms of radiation risk, and guidelines are suggested concerning possible alerts to the aeroplanes in case of events of exceptional magnitude. (author)

  3. Technical note

    DEFF Research Database (Denmark)

    Hermansen, Jonas S; Fonslet, Jesper; Søndergaard, Lasse R

    2017-01-01

    PURPOSE: To provide a faster and more intuitive way of designing shielding for PET facilities, while still relying on the principles of the AAPM 108 Taskforce guidelines, as well as illustrating the calculation output using dose maps that are easily evaluated. METHODS: A graphical user interface...... was developed, implementing an inverse AAPM method, wherein radiation sources and shield barriers are manually defined. Simulations are calculated using a user defined control mesh grid. DoseMapper simulations were verified against manual calculations using the AAPM guidelines, as well as compared with in......-situ dose rate measurements using four different dosemeters. RESULTS: DoseMapper simulations were virtually identical to manual calculations using AAPM guidelines, with a maximum relative error of

  4. Dose Evaluation and Quality Criteria in Dental Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Gori, C.; Rossi, F.; Stecco, A.; Villari, N.; Zatelli, G

    2000-07-01

    Radioprotection in dental radiology is of particular interest in the framework of the Revised Medical Exposure Directive for the great number of examinations involving the adult as well as the paediatric population (Article 9: Special Practice). The present study is intended to find the quality criteria of orthodontic imaging and for evaluating the dose absorbed within the dental and maxillary volume in connection with radiological examinations performed with either spiral CT, dental panoramic tomography or teleradiography. The X ray dose to organs sited in the body, neck, ocular and intracranial area was measured using lithium fluoride dosemeters, positioned in a Rando phantom. Quality criteria have been established by an expert radiologist considering the diagnostic information obtained in the images. The dosimetric data obtained were comparable with other authors', although with some differences due to technical characteristics. These result data are useful for choosing the patient's diagnostic path, considering the radiobiological risk associated with increasing orthodontic imaging. (author)

  5. Neutron field inside a PET Cyclotron vault room

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R. [UAZ, C. Cipres 10, 98068 Zacatecas (Mexico); Mendez, R. [CIEMAT, Ave. Complutense 22, 28040 Madrid (Spain); Iniguez, M.P. [Universidad de Valladolid, Po Prado de la Magdalena s/n, 47011 Valladolid (Spain); Climent, J.M.; Penuelas, I. [Servicio de Medicina Nuclear de la Clinica Universitaria de Navarra, Pamplona (Spain); Barquero, R. [Hospital Universitario Rio Hortega, Valladolid (Spain)]. e-mail: fermineutron@yahoo.com

    2006-07-01

    The neutron field around a Positron Emission Tomography cyclotron was investigated during {sup 18} F radioisotope production with an 18 MeV proton beam. In this study the Ion Beam Application cyclotron, model Cyclone 18/9, was utilized. Measurements were carried out with a Bonner sphere neutron spectrometer with pairs of thermoluminescent dosemeters (TLD600 and TLD700) as thermal neutron detector. The TLDs readouts were utilized to unfold the neutron spectra at three different positions inside the cyclotron's vault room. With the spectra the Ambient dose equivalent was calculated. Neutron spectra unfolding were performed with the BUNKIUT code and the UTA4 response matrix. Neutron spectra were also determined by Monte Carlo calculations using a detailed model of cyclotron and vault room. (Author)

  6. Development of a dosimetric system for emergency situation involving person of the public; Desenvolvimento de um sistema dosimetrico para situacoes de emergencia envolvendo pessoas do publico em geral

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Zelia Maria da

    1999-07-01

    A dosimetric system was developed for emergency situation based on electron spin resonance spectrometry (E.S.R.) and some materials such as tooth enamel, bovine bone, CaCO{sub 3} and sugar as detector. The purpose of this work was to find common materials, which are both reliable and sensitive and make possible quickly to assess the absorbed dose. The research includes the collection and preparation of samples, the evaluation, treatment and interpretation of ESR signal and the procedure for dose reconstruction. The calibration of the dosemeter was performed using gamma radiation from a Co-60 source. The results obtained confirm the variability of the use of this system in case of an accident. (author)

  7. Comparison of radiation dose to operator between transradial and transfemoral coronary angiography with optimised radiation protection: a phantom study.

    Science.gov (United States)

    Liu, Huiliang; Jin, Zhigeng; Jing, Limin

    2014-03-01

    A growing concern in applying radial access in cardiac catheterisation is the increased operator radiation exposure. This study used an anthropomorphic phantom to simulate transradial and transfemoral coronary angiography with optimised radiation protection conditions. Operator radiation exposure was measured with thermoluminescent dosemeters at predefined locations. Compared with the femoral route, the radial route was associated with a dose decrease of 15 % at the operator's chest level with optimised radiation shielding. However, radiation exposure to the operator's hand remained significantly higher when applying radial access even with collective protective equipment used (by a factor of 2). Furthermore, the efficiency of operator radiation protection was found to be dependent on the tube incidence. Awareness should be raised about the significant increase of radiation exposure to operators' hands in transradial coronary angiography. Protection to reduce the dose level to the hands is necessary and should be further improved.

  8. Biological dosimetry, scopes and limitations; Dosimetria biologica, alcances y limitaciones

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero C, C.; Brena V, M. [Departamento de Biologia, Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Salazar, Estado de Mexico (Mexico)

    1999-07-01

    The analysis of the aberrations in chromosomes is an alternative to establish the exposure dose to the radiation, when the information provided by the traditional physical methods is insufficient. There are diverse causes by which it can reached to apply an alternative system, such is the case of exposures of another persons to the management of radiation sources, which not carry physical dosemeter. Contrary case is to the occupational exposure personnel (OEP), what must to utilize some system for determining the exposure dose, even so can be needed the case for more information. In any case, the cells from the affected person are the alternative without the biological system be overlap to the physical, it is complementary. (Author)

  9. Method of evaluation of diagnostics reference levels in computerized tomography; Metodo de avaliacao de niveis de referencia de radiodiagnostico em tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Vega, Walter Flores

    1999-04-01

    Computerized tomography is a complex technique with several selectable exposition parameters delivering high doses to the patient. In this work it was developed a simple methodology to evaluate diagnostic reference levels in computerized tomography, using the concept of Multiple Scan Average Dose (MSAD), recently adopted by the Health Ministry. For evaluation of the MSAD, a dose distribution was obtained through a measured dose profile on the axial axis of a water phantom with thermoluminescence dosemeters, TLD-100, for different exam technique. The MSAD was evaluated hrough two distinct methods. First, it was evaluated by the integration of the dose profile of a single slice and, second, obtained by the integration on central slice of the profile of several slices. The latter is in of accordance with the ionization chamber method, suggesting to be the most practical method of dose evaluation to be applied in the diagnostic reference level assessment routine for CT, using TLDs. (author)

  10. Dosimetric characterization of a Tl new material of LiF: Mg, Cu, P; Caracterizacion dosimetrica de un nuevo material TL de LiF: Mg, Cu, P

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, P.R.; Avila, O. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Quiroz, C. [UAEM, Facultad de Medicina, 50180, Toluca, Estado de Mexico (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2004-07-01

    In this work the method of preparation of a new material T L is described of LiF: Mg, Cu, P and the preliminary results of the tests corresponding to their dosimetric characterization are reported. The carried out tests were: detection threshold, sensitivity, dissipation of the sign T L, answer T L in function of the dose of radiation gamma, among others. The results showed that this material when receiving the one thermal treatment of having erased of 280 C by 10 min, followed by 100 C for two hours, he/she has a detection threshold ten times but I lower that that of the TLD-100, is 21 times but sensitive that that of reference and the dissipation of the sign T L during two months was null. This new material T L overcomes in many aspects to the commercial dosemeters of its type. (Author)

  11. Fourth IRMF comparison of calibrations of portable gamma-ray dose- rate monitors 2001-2002 Ionising radiation

    CERN Document Server

    Lewis, V E

    2002-01-01

    The Ionising Radiations Metrology Forum (IRMF) organised a fourth comparison of calibrations of gamma-ray dose-rate monitors in which fifteen establishments in the UK participated. The exercise involved the circulation of three gamma-ray monitors for calibration in the fields produced using sup 1 sup 3 sup 7 Cs, sup 2 sup 4 sup 1 Am and sup 6 sup 0 Co. The instruments used were an Electra with MC 20 probe, a Mini-Instruments Mini-rad 1000 and a Siemens electronic personal dosemeter Mk 2 (EPD). The responses relative to 'true' dose equivalent rate were calculated by the individual participants and submitted to the for analysis along with details of the facilities and fields employed. Details of the estimated uncertainties were also reported. The results are compared and demonstrate generally satisfactory agreement between the participating establishments. However, the participants' treatment of uncertainties needs improvement and demonstrates a need for guidance in this area.

  12. Comparative study of thermoluminescent properties of LiF: Mg, Cu, P, LiF: Mg, Ti and TLD-100 irradiated with X-rays; Estudio comparativo de las propiedades termoluminiscentes de LiF: Mg, Cu, P, LiF: Mg, Ti y TLD-100 irradiados con rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Azorin, J.; Rivera, T.; Gonzalez, P.; Ortega, X.; Ginjaume, M. [Universidad Autonoma Metropolitana-Iztapalapa, 09000 Mexico D.F. (Mexico)

    2000-07-01

    The thermoluminescent properties (Tl) of LiF: Mg, Cu, P, and LiF: Mg, Ti, were investigated both developed in Mexico and comparing them with the properties of TLD-100 when they are exposure to X-rays. The Tl curve of LiF: Mg, Cu, P exhibited two peaks at 200 and 300 Centigrade. Its response Tl in function of dose resulted linear in the interval of 0.5 Gy until 5 Gy and its sensitivity to X-ray was around 25 times greater that of the TLD-100. Also it was measured the Tl response of the three materials in function of photon energy. The results showed that LiF: Mg, Cu, P has potential to be used as X-ray dosemeter. (Author)

  13. Characterization of the neutron field of the {sup 241}AmBe in a calibration room; Caracterizacion del campo de neutrones del {sup 241} AmBe en una sala para calibracion

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R. [UAZ, A.P. 336, 98000 Zacatecas (Mexico); Gallego, E.; Lorente, A. [Universidad Politecnica de Madrid, C. Jose Gutierrez Abascal 2, 28006 Madrid (Spain)] e-mail: rvega@cantera.reduaz.mx

    2003-07-01

    The field of neutrons produced by an isotopic source of neutrons of {sup 241} Am Be had been characterized. The characterization was carried out modeling those relevant details of the calibration room and simulating the neutron transport at different distances of the source. The calculated spectra were used to determine the equivalent environmental dose rate. A series of experiments were carried out with the Bonner sphere spectrometric system to measure the spectra in the same points where the calculations were carried out and with these spectra the rates of environmental dose were calculated. By means of a one sphere dosemeter type Berthold the rates of environmental dose were measured. To the one to compare the calculated spectra and measured its were found small differences in the group of the thermal neutrons due to the elementary composition used during the simulation. When comparing the derived rates starting from the calculated spectra with those measured it was found a maxim difference smaller to 13%. (Author)

  14. Personal radiation monitoring and assessment of doses received by radiation workers (1996)

    Energy Technology Data Exchange (ETDEWEB)

    Morris, N.D.

    1996-12-01

    Since late 1986, all persons monitored by the Australian Radiation Laboratory have been registered on a data base which maintains records of the doses received by each individual wearer. At present, the Service regularly monitors approximately 30,000 persons, which is roughly 90 percent of those monitored in Australia, and maintains dose histories of over 75,000 people. The skin dose for occupationally exposed workers can be measured by using one of the five types of monitor issued by the Service: Thermoluminescent Dosemeter (TLD monitor), Finger TLD 3, Neutron Monitor, Special TLD and Environmental monitor. The technical description of the monitors is provided along with the method for calculating the radiation dose. 5 refs., 7 tabs., 5 figs.

  15. Practical measurements of radiation dose in a neonatal intensive care unit

    Energy Technology Data Exchange (ETDEWEB)

    Smans, K.; Vanhavere, F.; Bosmans, H.

    2006-07-01

    The EURATOM directive 97/43 and the Belgian Royal Decree of July 20, 2001 impose today the application of the ALARA principle in medical practices. Priority should be given to paediatric examinations, especially for X-ray examinations undertaken in neonatal intensive care units. Within this framework, a dose study was started to assess the patient doses in one neonatal intensive care unit for the most common examinations. Direct measurement of radiation dose was done using highly sensitive thermoluminescent dosemeters (TLDs). The ESD was on average 66 {mu}Gy. Also DAP-measurements were performed. For RX-thorax an average DAP-value of 1,27 cGy.cm{sub w}as calculated. (Author)

  16. In vivo thermoluminescent dosimetry in studies of helicoid computed tomography and excretory urogram; Dosimetria termoluminiscente In vivo en estudios de tomografia computada helicoidal y urograma excretor

    Energy Technology Data Exchange (ETDEWEB)

    Cruz C, D.; Azorin N, J. [UAM-I, 09340 Mexico D.F. (Mexico); Saucedo A, V.M.; Barajas O, J.L. [Unidad de Especialidades Medicas, Secretaria de la Defensa Nacional, 11500 Mexico D.F. (Mexico)

    2005-07-01

    The dosimetry is the field of measurement of the ionizing radiations. It final objective is to determine the 'absorbed dose' for people. The dosimetry is vital in the radiotherapy, the radiological protection and the treatment technologies by irradiation. Presently work, we develop 'In vivo' dosimetry, in exposed patients to studies of helical computed tomography and excretory urogram. The dosimetry 'in vivo' was carried out in 20 patients selected aleatorily, for each medical study. The absorbed dose was measured in points of interest located in crystalline, thyroid, chest and abdomen of each patient, by means of thermoluminescent dosemeters (TLD) LiF: Mg,Cu,P + Ptfe of national fabrication. Also it was quantified the dose in the working area. (Author)

  17. Radiation exposure for medical staff performing quantitative coronary perfusion PET with 13N-ammonia

    DEFF Research Database (Denmark)

    Kristoffersen, Ulrik Sloth; Borgwardt, Henrik Gutte; Skovgaard, Dorthe Charlotte

    2009-01-01

    PURPOSE: To evaluate radiation doses to medical staff performing quantitative (13)N-ammonia myocardial perfusion positron emission tomography (PET). METHODS: Seventeen PET examinations were performed. Nine examinations consisted of two PET scans (one during rest and one after pharmacological stress...... with dipyridamole) and eight examinations consisted of three PET scans (additionally a scan after cold pressor testing). The two nuclear technologists and the physician attending the examinations were equipped with an electronic dosemeter over the chest and thermoluminescent dosimetry chips on the right index...... finger and wrist. RESULTS: The highest mean equivalent dose per examination for a staff member was 453 microSv (417-490 microSv) to the right index finger, 138 microSv (127-149 microSv) to the right wrist and 13 +/- 0.8 microSv to the chest. CONCLUSIONS: Myocardial perfusion PET with (13)N...

  18. Verification analysis of thermoluminescent albedo neutron dosimetry at MOX fuel facilities.

    Science.gov (United States)

    Nakagawa, Takahiro; Takada, Chie; Tsujimura, Norio

    2011-07-01

    Radiation workers engaging in the fabrication of MOX fuels at the Japan Atomic Energy Agency-Nuclear Fuel Cycle Engineering Laboratories are exposed to neutrons. Accordingly, thermoluminescent albedo dosemeters (TLADs) are used for individual neutron dosimetry. Because dose estimation using TLADs is susceptible to variation of the neutron energy spectrum, the authors have provided TLADs incorporating solid-state nuclear tracks detectors (SSNTDs) to selected workers who are routinely exposed to neutrons and have continued analysis of the relationship between the SSNTD and the TLAD (T/R(f)) over the past 6 y from 2004 to 2009. Consequently, the T/R(f) value in each year was less than the data during 1991-1993, although the neutron spectra had not changed since then. This decrease of the T/R(f) implies that the ratio of operation time nearby gloveboxes and the total work time has decreased.

  19. TLD determination of neutron dose contribution in medical linac

    Energy Technology Data Exchange (ETDEWEB)

    Cano, A.; Rivera, T.; Calderon A, J. A. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Azorin, J. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico); Villasenor N, L. F. [Hospital General de Mexico, Dr. Balmis No. 148, Col. Doctores, 06726 Mexico D. F. (Mexico); Vega C, H. R., E-mail: azorin@xanum.uam.m [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2011-02-15

    The increased use of Linacs with accelerating voltage higher than 10 MV in clinical radiotherapy is producing and increasing demand of accurate dosimetric measurements of the photon induced neutron contamination of the radiotherapy beams, due that the associated Bremsstrahlung X rays may produce neutrons as a result of subsequent photonuclear reactions with the different materials constituting the accelerator head. Thermal neutron fluences can be measured with TLD-600/TLD-700 pairs arranged in both a bare and a cadmium (Cd) foil covered methacry-late box. Neutron response of Tl dosemeters irradiated with two different neutron sources has been investigated. The shape of the glow curve of these TLDs after irradiation in a medical Linac and in a Pu Be neutron source has been studied to verify the contribution of neutrons to an additional dose to staff, patients and the general public, due to photonuclear reactions generating neutrons from medical Linacs. (Author)

  20. Comparison between a digital scanning system and a conventional screen film system in the full spine radiological procedure in pediatrics; Valoracion de un sistema de Scan digital frente a un sistema convencional cartulina pelicula en exploraciones de columna total en pediatria

    Energy Technology Data Exchange (ETDEWEB)

    Espana, M. L.; Gomez, G.; Romero, A.; Minambres, A.; Albi, G.; Floriano, A.; Rodirguez, A.; Lopez Franco, P.

    2004-07-01

    To compare from both dosimetry and image quality standpoints, a digital scanning system with a conventional screen film system, in the full spine radiological procedure. The standard patient is considered to be 12 years old, and a sample of forty patients referred for full spine radiological procedure has been studied. Gonad shielding has been used in all the patients, and its efficiency has been evaluated. Dosimetric study includes Kerma-area product, and thorax and gonad entrance surface dose. Kerma area product has been measured using a transmission camera, and for entrance surface dose estimation both thermoluminescent dosemeter LiF: Mg, Cu, P and LiF: Mg, Ti have been utilized. Three radiologists have evaluated the image quality according to the degree of fulfilment of the image quality criteria. (Author) 22 refs.

  1. Mapping of the radiation field of a mammography equipment using molybdenum and rhodium filters

    Energy Technology Data Exchange (ETDEWEB)

    Barreira, Jacqueline S.; Campos, Daniela; Vivolo, Vitor, E-mail: jacsales@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-07-01

    The use of X rays for diagnostic radiology is very common and important to Medicine, including mammographic diagnosis focusing decreasing of the doses applied to the patients and preserving high quality of the diagnostic image. A quality control program of the irradiation systems it is very necessary. The Instruments Calibration Laboratory (LCI) of IPEN perform calibration in dosemeters used in radiation dosimetry (in diagnostic radiology) for many years. The objective of that paper is determining the point of greatest intensity of the beam issued by the mammography equipment. Exposures were made with filters Rhodium and Molybdenum. That mapping is important before applied a routine quality control program of the mammography equipment and the calibration of instruments in the diagnosis. (author)

  2. Thermoluminescent characteristics of ZrO{sub 2}:Nd films; Caracteristicas termoluminiscentes de peliculas de ZrO{sub 2}:Nd

    Energy Technology Data Exchange (ETDEWEB)

    Vera B, G.; Rivera M, T. [Escuela Superior de Ingenieria Mecanica y Electrica-IPN, 04430 Mexico D.F. (Mexico); Azorin N, J. [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, 09340 Mexico D.F. (Mexico); Falcony G, C. [Centro de Investigacion y Estudios Avanzados-IPN, 07000 Mexico D.F. (Mexico); Garcia H, M.; Martinez S, E. [Instituto de Investigaciones en Materiales-UNAM, C.P. 04510 Mexico D.F. (Mexico)

    2002-07-01

    In this work it is exposed the obtained results after analysing the photo luminescent and thermoluminescent characteristics of activated zirconium oxide with neodymium (ZrO{sub 2} :Nd) and its possible application in the UV radiation dosimetry. The realized experiments had as objective to study the characteristics such as the optimum thermal erased treatment, the influence of light on the response, the response depending on the wavelength, the fadeout of the information, the temperature effect, the response depending on the time and the recurring of the response. The results show that the ZrO{sub 2} :Nd is a promising material to be used as Tl dosemeter for the UV radiation. (Author)

  3. National pattern for the realization of the unit of the dose speed absorbed in air for beta radiation. (Method: Ionometer, cavity of Bragg-Gray implemented in an extrapolation chamber with electrodes of variable separation, exposed to a field of beta radiation of {sup 90}Sr/{sup 90}Y); Patron Nacional para la realizacion de la unidad de la rapidez de dosis absorbida en aire para radiacion beta. (Metodo: Ionometrico, cavidad de Bragg-Gray implementada en una camara de extrapolacion con electrodos de separacion variable, expuesta a un campo de radiacion beta de {sup 90}Sr/{sup 90}Y)

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, M. T.; Morales P, J. R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2001-01-15

    From the year of 1987 the Department of Metrology of the ININ, in their Secondary Laboratory of Calibration Dosimetric, has a patron group of sources of radiation beta and an extrapolation chamber of electrodes of variable separation.Their objective is to carry out of the unit of the dose speed absorbed in air for radiation beta. It uses the ionometric method, cavity Bragg-Gray in the extrapolation chamber with which it counts. The services that offers are: i) it Calibration : Radioactive Fuentes of radiation beta, isotopes: {sup 90}Sr/{sup 90}Y; Ophthalmic applicators {sup 9}0{sup S}r/{sup 90}Y; Instruments for detection of beta radiation with to the radiological protection: Ionization chambers, Geiger-Muller, etc.; Personal Dosemeters. ii) Irradiation with beta radiation of materials to the investigation. (Author)

  4. Long-term measurements of H*(10) at aviation altitudes in the northern hemisphere.

    Science.gov (United States)

    Wissmann, F

    2006-01-01

    Monitoring the radiation field at aviation altitudes is achieved by the dosemeter system piDOS installed in a passenger aircraft. The basic detector is a 2 in. tissue-equivalent proportional counter (TEPC) mounted in a cabin-baggage-sized aluminium suitcase. The entire system was characterised in neutron and photon reference fields from which two calibration factors were determined according to the splitting of the measured dose deposition spectrum yd(y) into low-LET and high-LET regions. A total of 255 flights in the northern hemisphere was analysed. The dependencies of the ambient dose equivalent rates on altitude, latitude and solar activity have been determined. These new data extend the data base used in Germany for the validation of program codes to calculate the radiation exposure of air crew members.

  5. Radon Measurements in Kindergartens and Schools of Six Italian Regions

    Energy Technology Data Exchange (ETDEWEB)

    Gaidolfi, L.; Malisan, M.R.; Bucci, S.; Cappai, M.; Bonomi, M.; Verdi, L.; Bochicchio, F

    1998-07-01

    Radon concentration in 2173 schools of six Italian regions was measured with passive dosemeters in representative surveys. Regional arithmetic and geometric means and geometric standard deviations range from 49 to 222 Bq.m{sup -3}, from 38 to 129 Bq.m{sup -3} and from 1.9 to 2.7, respectively. For the sake of comparison, measured values were corrected for the seasonal variations obtained from the national survey in dwellings. In some regions, schools exhibit a higher average concentration than dwellings. However, when the floor and the geographical location of measurements is accounted for, there is better agreement. Therefore, radon measurements in schools as well as in houses may be useful for radon mapping. In some regions, a significant proportion of schools, showed radon concentration exceeding the action levels established in other countries. (author)

  6. The value of thyroid shielding in intraoral radiography.

    Science.gov (United States)

    Hoogeveen, Reinier C; Hazenoot, Bart; Sanderink, Gerard C H; Berkhout, W Erwin R

    2016-01-01

    To evaluate the utility of the application of a thyroid shield in intraoral radiography when using rectangular collimation. Experimental data were obtained by measuring the absorbed dose at the position of the thyroid gland in a RANDO(®) (The Phantom Laboratory, Salem, NY) male phantom with a dosemeter. Four protocols were tested: round collimation and rectangular collimation, both with and without thyroid shield. Five exposure positions were deployed: upper incisor (Isup), upper canine (Csup), upper premolar (Psup), upper molar (Msup) and posterior bitewing (BW). Exposures were made with 70 kV and 7 mA and were repeated 10 times. The exposure times were as recommended for the exposure positions for the respective collimator type by the manufacturer for digital imaging. The data were statistically analyzed with a three-way ANOVA test. Significance was set at p radiography.

  7. Occupational exposure to medical X rays in Poland

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, J.; Nowak, B.; Liniecki, J. (Inst. of Occupational Medicine, Lodz (Poland))

    1991-01-01

    Personal dosimetry in Poland indicates that exposure to X rays of workers engaged in surgical radiology is higher than that among other radiologists and auxiliary personnel, 0.9 as against 0.4 mSv per annum. This information, however, does not provide detailed insight into the exposures. To study this problem, the exposure of personnel employed in operating theatres and utilising fluoroscopy was investigated. With TL dosemeters, the distribution of doses to the body was measured on the surface of protective aprons and on the forehead, the wrist and the shoulder. The study embraced 20 centres in Poland engaged in cardiac pacemaker insertion, haemodynamic examinations of the heart, transcutaneous removal of kidney stones, radiological control of biliary routes and orthopaedic surgery. The results enable one to assess the average annual effective dose equivalent H{sub E} for workers and the corresponding dose equivalents H to the lens of the eye and the hands. (author).

  8. Estimate of the exposition to the ionizing radiation of the medical veterinarians and its assistants in radiology examinations veterinary medicine

    Energy Technology Data Exchange (ETDEWEB)

    Lima, G.; Braz, D.; Lopez, R. [Rio de Janeiro Univ. Federal, COPPE (Brazil); Mauricia, C. [Rio de Janeiro Univ. Federal, Instituto de Radioprotecao e Dosimetria (Brazil); Barroso, R. [Rio de Janeiro Univ. Federal, Universidade Estadual do Rio de Janeiro (Brazil)

    2006-07-01

    The absorbed ionizing radiation outside of the permissible limits, can cause biological damages e, therefore it must necessarily be monitored. The dosimetry thermoluminescent is a technique very used to detect expositions in operatorserefore they are sensible crystals the ionizing radiation and allows to evaluate if the dose of radiation is or not below of the restriction levels. In scientific literature many information do not exist on the exposition of a medical veterinarian, with this do not have many data of the individual monitoring of these workers, becoming the work it important for posterior studies. Ahead of this, it was carried through measured of the doses, using the thermoluminescence dosemeters LiF: Mg, Cu, P (TLD-100 H) in the position of the crystalline lens, thyroid, hand and thorax, in three clinics of radiology veterinary medicine, different, having the objective to determine the dose distribution that the workers of radiology veterinary medicine are submitted in one day of work. (authors)

  9. [The interaction of clofelin and ketamine in the body of patients].

    Science.gov (United States)

    Byshovets, S N

    1996-01-01

    Overall thirty-three patients (two groups) I-III ASA operated on with no premedication were examined. In group K an effective dose of ketamine (EDK) was determined, inducing unconsciousness during the intravenous administration with the aid of a dose-metering device. Because of an inadequate sedative effect, determining the effective dose of clonidine in the same way was found to be impossible without exceeding too much the permissible dose. 30 minutes after intravenous administration of a standard dose of clonidine (SDCl) we started infusing ketamine in group "KCl" as we did in group K. ED of ketamine was determined once again against the background of the action of clonidine (EDKCl). Deriving proportions by known EDK, EDKCl, and SDCl, a "mythical" dose EDCl was calculated. According to the published literature man loses consciousness with the dose exceeding the estimated EDCl 33.8-67.5-fold. interaction of clonidine and ketamine in the organism of patients is synergic by nature.

  10. Dose evaluation in diagnostic for computerized tomography; Evaluacion de dosis en diagnostico por tomografia computarizada

    Energy Technology Data Exchange (ETDEWEB)

    Flores, W.; Borges, J.C.; Mota, H. [Universidad Federal de Rio de Janeiro, PEN/COPPE/UFRJ. Caixa Postal 68509. 21945-970 Rio de Janeiro (Brazil)

    1998-12-31

    The patients which are subjected to computerized tomography tests are exposed to relatively high doses given as result doses on organs that are not matter to test. It was realized a dose levels raising in patients subjected to tests by T C, utilizing to measure this magnitude, TLD-100 thermoluminescent dosemeters which were put directly on the patient, in eye regions, thyroid, breast and navel; founding doses fluctuating between 29.10-49.39 mGy in organs examined and dose values between 0.21-29.10 mGy for organs that no matter to test. The applications of ionizing radiations in medicine do not have dose limits, but paying attention to the radiological protection optimization principle, it is recommended the use of clothes to anti-rays protection for zones not examined, getting with this to reduce the level doses as low as possible, without this to diminish the test quality. (Author)

  11. Dosimetric monitoring in Ukraine--present status and path to the future.

    Science.gov (United States)

    Chumak, V; Boguslavskaya, A

    2007-01-01

    Despite wide use of nuclear energy and radiation sources in industry and medicine, there is no centralised dose accounting system in Ukraine; existing dosimetry services operate obsolete manual thermoluminescence dosemeter (TLD) readers and do not meet modern proficiency standards. Currently, dosimetric monitoring is required for approximately 42,000 occupationally exposed workers, including 9100 in medicine, 17,000 employees of nuclear power plants and approximately 16,000 workers dealing with other sources of occupational exposure. This article presents the plan of elaboration of the United System for monitoring and registration of individual doses which has the aim of harmonisation of individual monitoring in Ukraine through securing methodical unity; scientific and methodological guidance of individual dosimetric control; procurement of common technical policy regarding nomenclature and operation of instrumentation; implementation of quality assurance programmes; development and support of information infrastructure, in particular operation of the national registry of individual doses; training and certification of personnel engaged in the system of individual dosimetric monitoring.

  12. Evaluation of noise environments during daily activities of university students.

    Science.gov (United States)

    Tristán Hernández, Edgar; Pavón García, Ignacio; López Navarro, Juan Manuel; Kolosovas-Machuca, Eleazar Samuel

    2016-01-01

    Noise conditions specifically in areas inside university facilities and its impact on the quality of life of university students are topics that have received little attention. This paper presents a study of the noise conditions in which university students of various institutions in Madrid, Spain, carry out their daily studies. A representative number of measurements was carried out using noise dosemeters and dataloggers in order to evaluate the levels of noise, noise dose and exposure to noise during school periods and extracurricular activities. The results were compared with the recommendations given by current environmental noise regulations. This paper was complemented with a survey to get to know how students perceive the exposure to noise in university environments.

  13. Saeteilyn kaeyttoe ja muu saeteilytoiminta. Vuosiraportti 1999; Radiation usage and other radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Rantanen, E. [ed.

    2000-05-01

    At the end of 1999, there were 1,753 valid safety licenses in Finland for the use of radiation. In addition, there were 2,054 responsible parties for dental x-ray diagnostics. The registry of STUK - Radiation and Nuclear Safety Authority listed 13,687 radiation sources and 278 radionuclide laboratories. The import of radioactive substances amounted to 7 448,000 GBq and export to 18,300 GBq. Short-lived radionuclides produced in Finland amounted to 52,500 GBq. In the year 1999 there were 10,601 workers monitored for radiation exposure at 1,187 work sites. Of these employees, 21% received an annual dose exceeding the recording level. The annual effective dose limit was not exceeded. The total dose recorded in the dose registry (sum of the individual dosemeter readings) was 4.7 Sv in 1999. During the year radon was monitored at 300 companies.

  14. Preliminary dosimetric characterisation of thermoluminescent materials for beta radiation monitoring at nuclear medicine services.

    Science.gov (United States)

    Cecatti, Sonia G P; Caldas, Linda V E

    2006-01-01

    Beta emitters are widely used in nuclear medicine for diagnostic and therapeutic purposes. The critical groups exposed to a radioactive patient include the staff, other patients and members of the public accompanying the patient. The aim of this work is to characterise thermoluminescent (TL) materials for the staff monitoring of nuclear medicine services that manipulate beta radiation solutions of (153)Sm. This study was performed using CaSO(4):Dy + Teflon pellets, produced at IPEN, with different dimensions. For the dosimetric characterisation, these TL dosemeters were exposed to gamma source ((60)Co) and to beta sealed sources ((90)Sr + (90)Y, (204)Tl and (147)Pm) and to a non-sealed source ((153)Sm). Results were obtained related to reproducibility, lower detection limits, calibration curves, angle and energy dependence of response. All tested materials show usefulness for monitoring of workers exposed to beta radiation.

  15. Advantages of passive detectors for the determination of the cosmic ray induced neutron environment

    CERN Document Server

    Hajek, M; Schoner, W; Vana, N

    2002-01-01

    Due to the pronounced energy dependence of the neutron quality factor, accurate assessment of the biologically relevant dose requires knowledge of the spectral neutron fluence rate. Bonner sphere spectrometers (BSSs) are the only instruments which provide a sufficient response over practically the whole energy range of the cosmic ray induced neutron component. Measurements in a 62 MeV proton beam at Paul Scherrer Institute, Switzerland, and in the CERN-EU high-energy reference field led to the assumption that conventional active devices for the detection of thermal neutrons inside the BSS, e.g. /sup 6/LiI(Eu) scintillators, also respond to charged particles when used in high-energy mixed radiation fields. The effects of these particles cannot be suppressed by amplitude discrimination and are subsequently misinterpreted as neutron radiation. In contrast, paired TLD-600 and TLD-700 thermoluminescence dosemeters allow the determination of a net thermal neutron signal. (12 refs).

  16. Dosimetry of beta particles using Li:Mg, Cu, P + Ptfe; Dosimetria de particulas beta usando Li: Mg, Cu, P + Ptfe

    Energy Technology Data Exchange (ETDEWEB)

    Olvera, L.; Azorin, J.; Rivera, T. [Depto. de Fisica, UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    This paper presents the experimental results of determining the thermoluminescence (Tl) response of LiF: Mg, Cu, P + Ptfe pellets excited with {sup 90}Sr/{sup 90}Y beta radiation. The glow curve exhibited three peaks which appear at 121 C, 178 C and 217 C . Its relative sensitivity is 49 with respect to that of the TLD-100 dosemeter taken as a reference. The minimal dose that could be measured was 750 mGy. The Tl response as a function of dose was linear in the range of 0.7 mGy to 22.5 mGy. The study of the repeatability of the information contained in the pellets showed a standard deviation of 2 %. (Author)

  17. Calibration methods of plane-parallel ionization chambers used in electron dosimetry; Metodos de calibracao de camaras de ionizacao de placas paralelas para dosimetria de feixes de eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Bulla, Roseli Tadeu

    1999-07-01

    The use of linear accelerators in radiotherapy is of great importance in Medicine, and according to international recommendations the electron beam dosimetry has to be performed using plane-parallel ionization chambers, previously calibrated in standard gamma radiation fields at accredited laboratories. In this work, calibration methods of plane-parallel ionization chambers used in dosimetry procedures of high energy electron beams of clinical accelerators were presented, tested and intercompared. The experiments were carried out using gamma radiation beams of {sup 60} Co at the Calibration Laboratory of Clinical Dosemeters at IPEN and electron beams od 4 to 16 MeV at the Radiotherapy Department of Hospital Israelita Albert Einstein, Sao Paulo. A method was chosen to be established at IPEN. Proposals of the calibration procedure, calibration certificate and data sheets are presented. (author)

  18. System for leaks inspection in a nuclear plant by means of a mobile robot; Sistema para inspeccion de fugas en una planta nuclear por medio de un robot movil

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, R.; Segovia de los Rios, J.A. [ININ, Km. 36.5 Carretera Mexico-Toluca, Salazar, Edo. de Mexico (Mexico)]. E-mail: ramses@nuclear.inin.mx

    2004-07-01

    In this work a supervision system that could allow to carry out the detection of leaks of vapor in pipe lines, using a mobile robot Pioneer 2 -D Xe, which is controlled by means of an external micro controller 68HC912B32 programmed in Forth and using diffuse control to travel a road by means of the one to follow one lines painted in the floor is described. The robot takes in his superior part, a thermographic camera that allows to determine if leaks of vapor exist in pipes and a dosemeter to measure the present radiation levels in the place, besides a video camera. This way, the personnel, can make sure of having a propitious situation to make the maintenance of the facilities. (Author)

  19. Neutron dosimetry based on nuclear track etched detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bouassoule, T.; Fernandez, F.; Marin, M.; Tomas, M. [Grup de Fisica de les Radiacions. Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)

    1999-07-01

    In this work, the response of a neutron dosimeter based on plastic track detectors has been studied. The detector geometry used consists on a C R-39 detector 500 m thick plus either a Makrofol converter 300 {mu} m thick or air used as converter, for the study of the response to fast or thermal neutrons respectively. The possibility of using Makrofol as a high energy neutron dosemeter has also been studied. In order to validate the results obtained from Monte Carlo simulations, a set of irradiations to monoenergetic neutron beams has been performed at the Ptb and to realistic fields at Cadarache neutron irradiation facilities. An excellent agreement has been found between the simulated and the experimental values. The lower detection limit value found for C R-39 and fast neutrons was 60 {mu} Sv. (Author)

  20. FXG dosimeter response for three-dimensional conformal radiotherapy using different evaluation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cavinato, Christianne C.; Campos, Leticia L., E-mail: ccavinato@ipen.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Souza, Benedito H.; Carrete Junior, Henrique; Daros, Kellen A.C.; Medeiros, Regina B., E-mail: bhsouza@unifesp.b, E-mail: daros.kellen@unifesp.b, E-mail: rbitel-li.ddi@epm.b [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Dept. de Diagnostico por Imagem; Giordani, Adelmo J. [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Servico de Radioterapia

    2011-07-01

    This work aims to compare the dose-response of the Fricke xylenol gel (FXG) dosimeter developed at IPEN using 270 Bloom gelatin from porcine skin made in Brazil evaluated using the magnetic resonance imaging (MRI) technique with the dosimetric response evaluated using the optical absorption (OA) spectrophotometry technique, in order to verify the possibility of quality assurance (QA) and reproducibility of FXG dosimeter to be carried out routinely using the OA technique for three-dimensional conformal radiotherapy (3DCRT) application using a 6 MV photons linear accelerator. The response in function of the absorbed dose of FXG dosimeter developed at IPEN presents linear behavior in clinical interest dose range when irradiated with Co-60 gamma radiation and 6 MV photons and evaluated using the MRI and OA techniques. The results indicate that the optical technique can be used for QA of FXG dosemeter when used in the possible application in QA of 3DCRT. (author)

  1. Measurement of absorbed dose by 7-GeV bremsstrahlung in a PMMA phantom

    CERN Document Server

    Job, P K; Semones, E

    1999-01-01

    High-energy electron storage rings generate energetic bremsstrahlung photons through radiative interaction of the particle beam with the residual gas molecules and other components inside the storage ring. At synchrotron radiation facilities, where beamlines are channeled out of the storage ring, a continuous bremsstrahlung spectrum, with a maximum energy of the stored particle beam, will be present. At the advanced photon source (APS), where the stored beam energy is 7 GeV, bremsstrahlung generated in the straight sections of the insertion device beamlines, which are a total of 15.38 m in length, can be significant. The contribution from each bremsstrahlung interaction adds up to produce a narrow mono-directional bremsstrahlung beam that comes down through the insertion device beamlines. The resulting absorbed dose distributions by this radiation in a 300 mmx300 mmx300 mm tissue substitute cube phantom were measured with LiF:Mg,Ti (TLD-700) thermoluminescent dosemeters. The normalized absorbed dose, in a cro...

  2. Changes in the chromogene properties of the betalaine; Cambios en las propiedades cromogenas de las betalainas inducidos por radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Arcos P, A.; Vega C, H.R. [Unidad Academica de Ciencias Nucleares, C. Cipres 10, Fracc. La Penuela, 98068, Zacatecas, Zac. (Mexico)

    2005-07-01

    The changes of coloration of four natural extracts were determined in function of the absorbed dose taken place by a source of rays gamma of Cs-137. The used natural extracts contain betalaine that are natural pigments of some plants as the beet root, of there their name. They are also in abundant form in the fruits (tunas) of some species of the Opuntia gender. The extracts were obtained by maceration, starting from beet root and three tuna varieties, and they were stabilized to pH 5.5 the change of coloration you determines in a spectrophotometer ultraviolet/visible by means of the absorbance from the samples to photons of 475, 535 and 600 nm of wave longitude. The absorbance was measured, to different intervals of time. The relationship settled down between the absorbed dose and the chromogene properties of the pigment, with the intention of using it as possible dosemeter. (Author)

  3. Changes in the chromogen properties of the betalaine induced by gamma radiation; Cambios en las propiedades cromogenas de las betalainas inducidos por radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Arcos P, A.; Vega C, H.R. [Unidad Academica de Ciencias Nucleares, C. Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2005-07-01

    The changes of coloration of four natural extracts in function of the absorbed dose produced by a gamma rays source of {sup 137} Cs were determined. The natural extracts used contain betalaines that are natural pigments of some plants as the beet about that their name. They are also in abundant form in the fruits (tunas) of some species of the Opuntia genus. The extracts were obtained by maceration, starting from beet and three tuna varieties, and they were stabilized to pH 5.5 The change of coloration it was determined in a visible ultraviolet spectrophotometer by means of the absorbance from the samples to photons of 475, 535 and 600 nm of wavelength. The absorbance to different intervals of time was measured. The relationship between the absorbed dose and the chromogene properties of the pigment, with the intention of using it as possible dosemeter was settled down. (Author)

  4. Evaluation of the neutrons spectrum near the Venus reactor: use of MCNPX-2.5C; Evaluation du spectre des neutrons pres du reacteur venus - utilisation de MCNPX-2.5C

    Energy Technology Data Exchange (ETDEWEB)

    Verboomen, B.; Coeck, M.; Baeten, P. [SCK.CEN, Centre d' Etude de l' Energie Nucleaire, Mol (Belgium)

    2003-07-01

    The present study has been justified by the choice of the Venus reactor (SCK-CEN) as a true work environment for the project of the fifth programme - frame E.V.I.D.O.S.. The objective of this programme is the evaluation, in neutron-photon combined field, and in true environment (nuclear industry), of the different methods of measurement used in neutron dosimetry. The project aims to the determination of abilities and limits of dosemeters and to establish methods to get doses equivalents from data gotten by spectrometry, personal and ambient dosimetry. For each environment, reference values have to be determined by spectrometry (energy and angle). The knowledge of the distribution in energy and in angle of neutrons allows then the calculation of the different doses equivalents. The determination of these references values by direct neutron calculation allows the validation of the Monte Carlo model. (N.C.)

  5. Neutron dosimetry at the reactor facility VENUS

    Energy Technology Data Exchange (ETDEWEB)

    Deboodt, P.; Vermeersch, F.; Vanhavere, F.; Minsart, G. [SCK-CEN, Belgian Nuclear Research Centre, Mol (Belgium)

    1997-09-01

    The reactor VENUS is a zero-power research reactor mainly devoted to studies on light water fuels. The need for undertaking a neutron spectrometric and dosimetric study became apparent when locally high neutron dose rates were measured. The spectrometric study is based on two approaches. The first is an experimental one in which the neutron spectrum was measured at three positions around the facility. The second is a theoretical one in which a numerical modelling of the neutron transport at the reactor site was performed in order to determine neutron spectra and fluence rates at different positions around the site. The measured and calculated spectra are interpreted in terms of the responses of different individual and environmental dosemeters. These responses are confronted with the in situ measurements. The impact of the ICRP 60 recommendations on the determined dose rates is also studied. (author).

  6. A new sensitive system for measurement of thermally and optically stimulated luminescence

    DEFF Research Database (Denmark)

    Markey, B.G.; Bøtter-Jensen, L.; Poolton, N.R.J.

    1996-01-01

    demand for improvements that would allow lower doses (or less sensitive materials) to be measured, with increased accuracy. This article reports on a new generation of designs that are intended to meet these demands. Substantial increases in sensitivity of the instruments are made by replacing the lens...... optics of the system with a combination of ellipsoidal mirrors and light guides, which also serve to make the system more flexible in choice of excitation source when OSL measurements are required. A variety of new light sources might be employed, adapted to allow the most efficient wavelengths...... of excitation to be used for the particular dosemeter under study. The capabilities and characteristics of the new design are described, and comparison with the existing TL/OSL system is made throughout the article....

  7. Thermoluminescent dosimetry in pediatric patients subjected to TAC cranium multi cutting studies; Dosimetria termoluminiscente en pacientes pediatricos sometidos a estudios de TAC multicorte de craneo

    Energy Technology Data Exchange (ETDEWEB)

    Tabares V, M.J.; Azorin N, J. [UAM-Iztapalapa, 09340 Mexico D.F. (Mexico); Azorin V, J.C. [CICATA-IPN, 11500 Mexico D.F. (Mexico)]. e-mail: azorin@xanum.uam. mx

    2007-07-01

    Full text: In this work the doses to critical organs in pediatric patient subjected to studies of multi cutting skull tomography were determined. The study included patient smaller than 16. The used tomograph was a Siemens Somaton 16 plus multi cutting. The dosimetry one carries out with thermoluminescent dosemeters of LiF:Mg,Cu,P +Ptfe of national production. This dosemeters type was used due to it characteristics, such as low fading, equivalence with the tissue, easy handling and reading and independence of it answer with the radiation energy. The value of the absorbed doses in organs in the simple study results half of the obtained value in the contrasted study that which indicates that the CTDI{sub vol} is proportional to the dose to organ. In the case of the skull three-dimensional reconstruction tomography the CTDI{sub vol} was practically the same one that for simple tomography was practically; however, the doses to organs differed significantly. When comparing the TDI{sub vol} value of the three-dimensional reconstruction tomography with that of the contrasted tomography the obtained reason it was 1:2; however, the doses to organ didn't show the same relationship and the absorbed dose in the case of the thyroid gland was even bigger in the study of three-dimensional reconstruction. The value of the CTDI{sub vol} is a good indicator of the exposure factors selected for the tomographic exploration and it is useful for the determination of the effective dose, but it doesn't indicate the absorbed dose to organ. (Author)

  8. Media glandular dose in mammography;Dosis glandular media en mamografia

    Energy Technology Data Exchange (ETDEWEB)

    Duran M, H. A.; Hernandez O, M.; Pinedo S, A.; Guerra M, J. A.; Gonzalez G, R.; Salas L, M. A.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada en Tecnologia Avanzada, Av. Legaria 694, 11500 Mexico D. F. (Mexico); Azorin N, J., E-mail: hduran20_1@hotmail.co [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, 09340 Mexico D. F. (Mexico)

    2009-10-15

    The objective of this work was to determine the media glandular dose of the patients group who most frequently are exposed at mammographic studies in the General Hospital of Zone No. 1 of IMSS in Zacatecas, later to compare this dose with the value that establishes the Mexican Official Standard and to know risk-benefit that a patient is exposed when it is realized studies of this nature. This with the purpose of to know if the patients who are realized this type of studies are exhibited to irradiations of unnecessary way. In order to obtain the media glandular dose, first it was choose the age group of feminine population that is predominant to this suffering. Of the classification of the age group it was determine the frequency of each thickness of mamma, and on the basis of the thickness of the compressed mamma the conditions were registered with it radiates the patient. When having the age and compressed mamma thickness of patient and the voltage, current, anode/filter that uses the mammography equipment for to radiate it was calculated the media glandular dose. The media glandular dose was calculated using two algorithms proposed in literature and thermoluminescent dosemeters. For the case of the thermoluminescent dosemeters were used two phantoms. In this study was detected that the limits, with that they radiate the patients who are exposed at mammographic studies it is by underneath of 3 mGy. Finally, it was detected that the Mexican Official Standard lacks of elements to offer radiological limits for the mammography area, because in this standard they are excluded the radiological limits for anode and filter of Mo/Rh and Rh/Rh. To know the dose applying these anodes and filters is of extreme importance because 85% of the population that is exposed to this studies type was radiated with anode and filter of Mo/Rh and Rh/Rh. (Author)

  9. Feasibility of using glass-bead thermoluminescent dosimeters for radiotherapy treatment plan verification

    Science.gov (United States)

    Jordan, Tom J; Distefano, Gail; Bradley, David A; Spyrou, Nicholas M; Nisbet, Andrew; Clark, Catharine H

    2015-01-01

    Objective: To investigate the feasibility of using glass beads as novel thermoluminescent dosemeters (TLDs) for radiotherapy treatment plan verification. Methods: Commercially available glass beads with a size of 1-mm thickness and 2-mm diameter were characterized as TLDs. Five clinical treatment plans including a conventional larynx, a conformal prostate, an intensity-modulated radiotherapy (IMRT) prostate and two stereotactic body radiation therapy (SBRT) lung plans were transferred onto a CT scan of a water-equivalent phantom (Solid Water®, Gammex, Middleton, WI) and the dose distribution recalculated. The number of monitor units was maintained from the clinical plan and delivered accordingly. The doses determined by the glass beads were compared with those measured by a graphite-walled ionization chamber, and the respective expected doses were determined by the treatment-planning system (TPS) calculation. Results: The mean percentage difference between measured dose with the glass beads and TPS was found to be 0.3%, −0.1%, 0.4%, 1.8% and 1.7% for the conventional larynx, conformal prostate, IMRT prostate and each of the SBRT delivery techniques, respectively. The percentage difference between measured dose with the ionization chamber and glass bead was found to be −1.2%, −1.4%, −0.1%, −0.9% and 2.4% for the above-mentioned plans, respectively. The results of measured doses with the glass beads and ionization chamber in comparison with expected doses from the TPS were analysed using a two-sided paired t-test, and there was no significant difference at p glass-bead TLDs as dosemeters in a range of clinical plan verifications. Advances in knowledge: Commercial glass beads are utilized as low-cost novel TLDs for treatment-plan verification. PMID:26258442

  10. Indoor radon survey in dwellings of nine cities in the Eastern and the Western provinces of Saudi Arabia.

    Science.gov (United States)

    Abu-Jarad, F; Fazal-ur-Rehman; Al-Jarallah, M I; Al-Shukri, A

    2003-01-01

    The results of a first phase of an indoor radon survey in a total of 1610 dwellings distributed in nine cities of the Eastern and the Western provinces of Saudi Arabia are presented. The objective of this radon survey was to obtain representative indoor radon data for seven cities in the Eastern province. Khafji, Hafr Al-Batin, Abqaiq, Qatif, Al-Ahsa, Dammam and Khobar and to compare this with two cities in the Western province, Madina and Taif. So far, detailed radon data is not available for Saudi Arabia: therefore, this radon survey provides a base line for Saudi Arabia in the Radon World Atlas. On average, 200 indoor radon dosemeters were distributed in each city and placed for a period of one year starting from May 2001 to May 2002. The total number of collected dosemeters was 847. A total of 724 houses and 98 schools were covered in this survey. The results of the survey in the cities showed that the overall minimum, maximum and average radon concentrations were 1, 137 and 22 Bq m(-3), respectively. Geometric mean and geometric standard deviations of the radon distribution were found to be 18 and 1.92, respectively. In one of the dwellings in Qatif city, radon concentration, measured by a passive system and then confirmed by an active system, was found to be 535 +/- 23 and 523 +/- 22 Bq m(-3), respectively. The result of a radon survey in 98 schools showed that the minimum, maximum and average radon concentrations were 1, 70 and 19 Bq m(-3), respectively. The average radon concentration for each city was also determined. The lowest average radon concentration (8 Bq m(-3)) was found in Al-Ahsa while the highest average concentration (40 Bq m(-3)) was found in Khafji.

  11. Indoor radon survey in dwellings of nine cities in the eastern and western provinces of Saudi Arabia

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Jarad, F.; Fazal-ur-Rehman; Al-Jarallah, M.I.; Al-Shukri, A

    2003-07-01

    The results of a first phase of an indoor survey in a total of 1610 dwellings distributed in nine cities of the Eastern and the Western provinces of Saudi Arabia are presented. The objective of this radon survey was to obtain representative indoor radon data for seven cities in the Eastern province, Khafji, Hafr Al-Batin, Abqaiq, Qatif, Al-Ahsa, Dammam and Khobar and to compare this with two cities in the Western province, Madina and Taif. So far, detailed radon data is not available for Saudi Arabia; therefore, this radon survey provides a base line for Saudi Arabia in the Radon World Atlas. On average, 200 indoor radon dosemeters were distributed in each city and placed for a period of one year starting from May 2001 to May 2002. The total number of collected dosemeters was 847. A total of 724 houses and 98 schools were covered in this survey. The results of the survey in the cities showed that the overall minimum, maximum and average radon concentrations were 1, 137 and 22 Bq m {sup -3}, respectively. Geometric mean and geometric standard deviations of the radon distribution were found to be 18 and 1.92, respectively. In one of the dwellings in Qatif city, radon concentration, measured by a passive system and then confirmed by an active system, was found to be 535 {+-} 23 and 523 {+-} 22 Bq m {sup -3}, respectively. The result of a radon survey in 98 schools showed that the minimum, maximum and average radon concentrations were 1, 70 and 19 Bq m{sup -3}, respectively. The average radon concentration for each city was also determined. The lowest average radon concentration (8 Bq m{sup -3}) was found in Al-Ahsa while the highest average concentration (40 Bq m {sup -3}) was found in Khafji. (author)

  12. Occupational exposure in orthopedic procedures under fluoroscopic control

    Directory of Open Access Journals (Sweden)

    Edyta Owsiak

    2017-04-01

    Full Text Available Background: In interventional radiology the highest radiation doses are usually recorded for both the medical staff and the patients. Interventional procedures with X-rays are implemented in a number of medical specializations. This paper concerns the exposure of interventional teams performing orthopedic procedures under X-rays control. Material and Methods: Doses for interventional teams were measured in the 3 Łódź hospitals. Thermoluminescent dosemeters were applied to measure the following dose equivalents: Hp(3 for eye lens, Hp(0.07 for palm skin, Hp(10 at the level of the neck without a protective shield (i.e., collar and Hp(10 for the whole body on the front surface of the trunk (measured under the protective apron at the level of the chest. Results: Doses for the operator who performs surgery, assisting physicians and scrub nurse were measured during 95 procedures. The highest doses were received by the operator the dose for eyes per 1 procedure did not exceed 0.1 mSv, the highest dose for hands was 1.6 mSv and the highest recorded effective dose was 0.02 mSv. Conclusions: On the basis of the results of measurements and their comparison with the values reported in the literature it may be concluded that the obtained results fall within the published reference range (for non-vascular procedures. This proves the compatibility of practice in the monitored Łódź hospitals with routine methodology applied in other interventional departments. The measurement results confirm that the usage of thermoluminescent dosimetry is fully adequate for the evaluation of exposure in interventional radiology and that the usage of at least 2 dosemeters for that staff is necessary. Med Pr 2017;68(2:221–227

  13. Eye lens dose in interventional cardiology.

    Science.gov (United States)

    Principi, S; Delgado Soler, C; Ginjaume, M; Beltran Vilagrasa, M; Rovira Escutia, J J; Duch, M A

    2015-07-01

    The ICRP has recently recommended reducing the occupational exposure dose limit for the lens of the eye to 20 mSv y(-1), averaged over a period of 5 y, with no year exceeding 50 mSv, instead of the current 150 mSv y(-1). This reduction will have important implications for interventional cardiology and radiology (IC/IR) personnel. In this work, lens dose received by a staff working in IC is studied in order to determine whether eye lens dose monitoring or/and additional radiological protection measures are required. Eye lens dose exposure was monitored in 10 physicians and 6 nurses. The major IC procedures performed were coronary angiography and percutaneous transluminal coronary angioplasty. The personnel were provided with two thermoluminescent dosemeters (TLDs): one calibrated in terms of Hp(3) located close to the left ear of the operator and a whole-body dosemeter calibrated in terms of Hp(10) and Hp(0.07) positioned on the lead apron. The estimated annual eye lens dose for physicians ranged between 8 and 60 mSv, for a workload of 200 procedures y(-1). Lower doses were collected for nurses, with estimated annual Hp(3) between 2 and 4 mSv y(-1). It was observed that for nurses the Hp(0.07) measurement on the lead apron is a good estimate of eye lens dose. This is not the case for physicians, where the influence of both the position and use of protective devices such as the ceiling shield is very important and produces large differences among doses both at the eyes and on the thorax. For physicians, a good correlation between Hp(3) and dose area product is shown. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Eye doses to staff in a nuclear medicine department.

    Science.gov (United States)

    Summers, Elizabeth C; Brown, Janis L E; Bownes, Peter J; Anderson, Shona E

    2012-05-01

    Occupational radiation doses to the Nuclear Medicine Department staff at Mount Vernon Hospital are routinely measured using optically stimulated luminescence dosemeters for whole-body effective dose and ring thermoluminescence dosemeters (TLDs) for finger dose. In 2002, a project was carried out using LiF:Mg,Cu,P Chinese TLDs to measure the dose to the lens of the eye received by staff during normal working procedures. Separate pairs of TLDs were worn by staff on their forehead between their eyes while dispensing and releasing in the radiopharmacy, injecting, and when administering I-131 capsules to patients. The dose received was calculated using calibration data from identical TLDs irradiated with Tc-99m, I-131, and the Ir-192 source of a Gammamed High Dose Rate (HDR) treatment unit. Data were collected over a 5-month period and the mean dose to the eye was calculated for each procedure. Using a typical yearly workload, the annual dose to the eye for a single member of staff was calculated and found to be 4.5 mSv. The occupational eye dose limit was, at the time, 150 mSv; therefore, staff were well below the level (3/10th of this limit) that would have required them to be classified. However, there have been large increases in radiopharmacy production and I-131 therapies administered at Mount Vernon in subsequent years. It is therefore expected that the eye dose received by staff will have increased to be significantly higher than 4.5 mSv and will in fact be greater than 6 mSv, which is 3/10th of the proposed new dose limit and would require these staff to become classified workers.

  15. Feasibility of using glass-bead thermoluminescent dosimeters for radiotherapy treatment plan verification.

    Science.gov (United States)

    Jafari, Shakardokht M; Jordan, Tom J; Distefano, Gail; Bradley, David A; Spyrou, Nicholas M; Nisbet, Andrew; Clark, Catharine H

    2015-01-01

    To investigate the feasibility of using glass beads as novel thermoluminescent dosemeters (TLDs) for radiotherapy treatment plan verification. Commercially available glass beads with a size of 1-mm thickness and 2-mm diameter were characterized as TLDs. Five clinical treatment plans including a conventional larynx, a conformal prostate, an intensity-modulated radiotherapy (IMRT) prostate and two stereotactic body radiation therapy (SBRT) lung plans were transferred onto a CT scan of a water-equivalent phantom (Solid Water(®), Gammex, Middleton, WI) and the dose distribution recalculated. The number of monitor units was maintained from the clinical plan and delivered accordingly. The doses determined by the glass beads were compared with those measured by a graphite-walled ionization chamber, and the respective expected doses were determined by the treatment-planning system (TPS) calculation. The mean percentage difference between measured dose with the glass beads and TPS was found to be 0.3%, -0.1%, 0.4%, 1.8% and 1.7% for the conventional larynx, conformal prostate, IMRT prostate and each of the SBRT delivery techniques, respectively. The percentage difference between measured dose with the ionization chamber and glass bead was found to be -1.2%, -1.4%, -0.1%, -0.9% and 2.4% for the above-mentioned plans, respectively. The results of measured doses with the glass beads and ionization chamber in comparison with expected doses from the TPS were analysed using a two-sided paired t-test, and there was no significant difference at p glass-bead TLDs as dosemeters in a range of clinical plan verifications. Commercial glass beads are utilized as low-cost novel TLDs for treatment-plan verification.

  16. Characterization of silicates and calcium carbonates applied to high-dose dosimetry; Caracterizacao de silicatos e carbonatos de calcio aplicados a dosimetria de doses altas

    Energy Technology Data Exchange (ETDEWEB)

    Vila, Gustavo Barreto

    2012-07-01

    The predominant isomorphous form in the biominerals studied in this work (oyster shell, coral, mother of pearl and shell) was aragonite. The appearance of the calcite phase occurred at 500 deg C at a heating rate of 10 deg {sup C}/s for all samples except for the coral sample, which was 400 deg C, independent of the heating rate. The most abundant element in the biominerals samples was Ca in the CaO form, and in the silicates (tremolite, diopside and rhodonite) Si in the SiO form. The most common trace element observed in the biominerals samples was Fe. The analyses of electron paramagnetic resonance showed lines of Mn{sup 2+} in the coral and mother-of-pearl samples before irradiation. In the case of the irradiated samples, the defects found were CO{sub 2}{sup -}, CO{sub 3}{sup 3-}, CO{sub 3}{sup -} and SO{sub 2}{sup -}, in the g range between 2.0010 and 2.0062. In the analyses by optical absorption of biominerals, transitions due to the presence of Mn in the samples were found. A thermoluminescent (TL) peak at approximately 140 deg C was found for the biominerals and at 180 deg C for silicates, which intensity depends directly on the dose. For samples exposed to different types of radiation, the TL peak occurred at lower temperatures. From the dose-response curves obtained for these materials, it was possible to determine a linear range for which their application in high dose dosimetry becomes possible. Taking into account the radiation type, among biominerals and silicates, the lowest detectable dose (40mGy) to gamma radiation was achieved for oyster shell samples using the measuring technique of optically stimulated luminescence (OSL). Using beta radiation, for diopside and tremolite samples the lowest detectable dose of 60mGy was obtained. For all samples, using the TL, OSL and thermally stimulated exoelectron emission (TSEE) techniques in alpha, beta and gamma radiation beans a good response reproducibility was obtained. Therefore, the samples characterized

  17. Understanding optically stimulated charge movement in quartz and feldspar using time-resolved measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ankjaergaard, C.

    2010-02-15

    Thermoluminescence (TL) and optically stimulated luminescence (OSL) from quartz and feldspar are widely used in accident dosimetry and luminescence dating. In order to improve already existing methods or to develop new methods towards extending the current limits of the technique, it is important to understand the charge movement within these materials. Earlier studies have primarily focussed on examination of the trap behaviour; however, this only tells half of the story as OSL is a combination of charge stimulation and recombination. By using time-resolved OSL (TR-OSL), one can directly examine the recombination route(s), and thus obtain insight into the other half of the process involved in luminescence emission. This thesis studies the TR-OSL and optically stimulated phosphorescence signals from quartz and feldspars spanning several orders of magnitude in time (few ns to the seconds time scale) in order to identify various charge transport mechanisms in the different time regimes. The techniques employed are time-resolved OSL, continuous-wave OSL, TL, optically stimulated exo-electron (OSE) emission and time-resolved OSE. These different techniques are used in combination with variable thermal or optical stimulation energy. The thesis first delves into three main methodological developments, namely (i) research and development of the equipment for TR-OSL measurements, (ii) finding the best method for multiple-exponential analysis of a TR-OSL curve, and (iii) optimisation of the pulsing configuration for the best separation of quartz OSL from a mixed quarts-feldspar sample. It then proceeds to study the different charge transport mechanisms subsequent to an optical stimulation pulse in quartz and feldspars. The results obtained for quartz conclude that the main lifetime component in quartz represents an excited state lifetime of the recombination centre, and the more slowly decaying components on the millisecond to seconds time scale arise from charge recycling

  18. Evaluation and development of X-ray detectors for dosimetry; Evaluierung und Entwicklung von Roentgendetektoren fuer die Dosimetrie

    Energy Technology Data Exchange (ETDEWEB)

    Boehnel, Michael

    2012-03-28

    This thesis presents the development and evaluation of a new personal dosemeter, based on the technology of energy-resolving pixelated photon-counting X-ray detectors. The basis of the development is a detailed study of the Timepix detector. The main focus is on the investigation of the energy resolving properties of the Timepix detector in counting mode and in the spectroscopic time-over-threshold mode. The approach for the production of fluorescence radiation for the detector calibration, necessary for the experiments, is presented. By using Monte Carlo simulations the spectral distribution of the resulting fluorescence spectra in dependence on the fluorescence material, the used primary X-ray radiation and the arrangement of the laboratory setup is discussed. Besides the actual fluorescence lines, the simulated calibration spectra also contain the background of scattered primary X-ray photons and fluorescence radiation contributions from parts of the experimental setup. Furthermore, the simulated spectra exhibit the corrected intensity conditions of the fluorescence emissions of the K- and L-shell. These calibration spectra permit a better match of measurements and simulations than the simplified fluorescence spectra used so far. For the detector calibration in counting mode, accelerated energy calibration methods are introduced. From measuring energy deposition spectra, the energy resolution of single pixels and the energy resolution of the complete detector could be determined by the application of a global energy calibration. It was shown that the influence of the threshold dispersion broadens the energy resolution of the single pixels, depending on the given energy deposition. The resulting energy resolution of the whole pixel matrix is thereby reduced. The negative effect of the threshold dispersion can be eliminated by the application of a single-pixel calibration. The relative energy resolution of the Timepix detector operated in the counting mode can

  19. 24. ATSR congress - Proceedings; 24e congres ATSR - Recueil des conferences

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-06-15

    -G. Mozziconacci); 18 - experience feedback after 4 years of implementation of diagnostic reference levels (A. Talbot); 19 - exposure levels at the dental office (J-M. Ariscon); 20 - implementation of the zoning by-law at Cadarache centre, methodology and first experience feedbacks (M. Juanola, S. Bontemps) 21 - cleansing techniques: radiological survey of a contaminated site (D. Dubot); 22 - Simulation of a work site accident (B. Carrez); 23 - neutron dosimetry developments, automatic trace detection system (M. Million); 24 - The new IRSN's radio-photoluminescent dosemeter (P. Fraboulet); 25 - Intercomparison of neutron dosemeters (M. Roig, P. Esteve); 26 - continuous improvement of workers radiation protection: training and certification (A. Bontemps); 27 - sources management (T. Juhel); 28 - Poster presentation: training of the employees of Cadarache radiation protection service to emergency exposure (M. Juanola)

  20. TLD personnel dosimetry and its relationship with the radiodiagnostic training; Dosimetria personal TLD y su relacion con la capacitacion en radiodiagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Gaona, E.; Franco E, J.G. [DEHA, Universidad Autonoma Metropolitana-Xochimilco, Mexico D.F. (Mexico); Gaona C, E. [Universidad Tecnologica de Mexico, Mexico D.F. (Mexico)

    2002-07-01

    The personnel dosimetry and the training in radiological protection in radiodiagnostic in Mexico before 1997 were almost nonexistent except few services of public and private radiology, we can to say that the personnel dosimetry and the obligatory training was born in the year 1997, together with the present Mexican Official Standards in radiology. This study has the purpose to make an evaluation of the personnel dosimetry of 110 radiology services distributed in the Mexican Republic for the year 2001 and to estimate the annual and bimonthly mean doses, as well as its trust intervals and its relationships with the personnel training in radiological protection by means of a sampling that was realized in two stages (1997 and 2000) in the metropolitan area of Mexico City. The results show that the received doses by the medical and technical personnel in the participating radiology services are in the 0.03 mSv and 0.94 mSv interval and the mean is 0.25 mSv. The estimated annual personnel dose would be in the 0.18 mSv to 5.64 mSv interval, which are values very lower to the annual dose limit that is 50 mSv and its magnitude is similar to the effective annual dose by natural background radiation. In the first stage in training was found that there is not a significant difference in the response frequencies among the medical and technical personnel with a p < 0.05. The 52% of the occupational exposure personnel of radiology uses dosemeter, but only 17% of them know the dose reports. the 15.8% of personnel considers that dosemeter protects against radiation and only 16.5% knows the annual maximum permissible dose for stochastic effects. The second stage, the results shown that there is a significant difference in the response of frequencies among medical and technical personnel, the same results which are obtained for members and non members of a professional association with a p < 0.05. The 38% has personnel dosimetry, the 19% knows the principles of radiological

  1. Occupational radiation exposure in Germany in 2013-2014. Report of the radiation protection register; Die berufliche Strahlenexposition in Deutschland 2013-2014. Bericht des Strahlenschutzregisters

    Energy Technology Data Exchange (ETDEWEB)

    Frasch, Gerhard; Kammerer, Lothar; Karofsky, Ralf; Mordek, Else; Schlosser, Andrea; Spiesl, Josef

    2015-10-15

    In Germany, persons who are occupationally exposed to ionising radiation are monitored by several official dosimetry services that transmit the dose records about individual radiation monitoring to the Radiation Protection Register of the Federal Office for Radiation Protection (BfS). The purpose of the Radiation Protection Register is to supervise the keeping of the dose limits and to monitor the compliance with the radiation protection principle ''Optimisation'' by performing detailed annual statistical analyses of the monitored persons and their radiation exposure. The annual report of the Radiation Protection Register provides information about status and development of occupational radiation exposure in Germany. In 2014, about 358,000 workers were monitored with dosemeters for occupational radiation exposure. The number increased continuously by totally 5 % into the past five years. 15 % of the monitored persons received measurable personal doses. The average annual dose of these exposed workers was 0.50 mSv corresponding to less than 3 % of the annual dose limit of 20 mSv for radiation workers. In total, two persons exceeded the annual dose limit of 20 mSv, i.e. less than one case per 100,000 monitored persons. The collective dose of the monitored persons decreased to 26.0 Person-Sv, the lowest value since the last fifty years of occupational dose monitoring. 45 airlines calculated the route doses of 39,500 aircraft crew members by using certified computer pro-grammes for dose calculation and sent the accumulated monthly doses via the Federal Office for Civil Aviation (''Luftfahrt-Bundesamt, LBA'') to the BfS. The collective dose of the aircraft crew personnel is 74.8 person-Sv, and thus significantly higher than the total collective dose of the workers monitored with personal dosemeters. The annual average dose of aircraft crew personnel was 1.89 mSv in 2014. In 2014, about 58,500 outside-workers were in possession of

  2. Occupational radiation exposure in Germany in 2011. Report of the radiation protection register; Die berufliche Strahlenexposition in Deutschland 2011. Bericht des Strahlenschutzregisters

    Energy Technology Data Exchange (ETDEWEB)

    Frasch, Gerhard; Kammerer, Lothar; Karofsky, Ralf; Mordek, Else; Schlosser, Andrea; Spiesl, Josef

    2013-04-15

    In Germany, persons who are occupationally exposed to ionising radiation are monitored by several official dosimetry services that transmit the dose records about individual radiation monitoring to the Radiation Protection Register of the Federal Office for Radiation Protection (BfS). The purpose of the Radiation Protection Register is to supervise the keeping of the dose limits and to monitor the compliance with the radiation protection principle ''Optimisation'' by performing detailed annual statistical analyses of the monitored persons and their radiation exposure. The annual report of the Radiation Protection Register provides information about status and development of occupational radiation exposure in Germany. In 2011, about 350,000 workers were monitored with dosemeters for occupational radiation exposure. The number increased during the past five years continuously by 10 %. Only 19 % of the monitored persons received measurable personal doses. The average annual dose of these exposed workers was 0.58 mSv corresponding to 3 % of the annual dose limit of 20 mSv for radiation workers. In total, 7 persons exceeded the annual dose limit of 20 mSv, i.e. two cases per 100,000 monitored persons. The collective dose of the monitored persons decreased to 38.5 Person-Sv, the lowest value since the last fifty years of occupational dose monitoring. In 2010, 45 airlines calculated the route doses of 39,000 members of the aircraft crew personnel by using certified computer programmes for dose calculation and sent the accumulated monthly doses via the Federal Office for Civil Aviation (''Luftfahrt-Bundesamt, LBA'') to the BfS. The collective dose of the aircraft crew personnel is 83 person-Sv, and thus significantly higher than the total collective dose of the workers monitored with personal dosemeters (38.5 person-Sv). The annual average dose of aircraft crew personnel was 2.12 mSv and decreased compared to 2010 (2,30 mSv). In 2011

  3. Occupational radiation exposure in Germany in 2012. Report of the radiation protection register; Die berufliche Strahlenexposition in Deutschland 2012. Bericht des Strahlenschutzregisters

    Energy Technology Data Exchange (ETDEWEB)

    Frasch, Gerhard; Kammerer, Lothar; Karofsky, Ralf; Mordek, Else; Schlosser, Andrea; Spiesl, Josef

    2014-04-15

    In Germany, persons who are occupationally exposed to ionising radiation are monitored by several official dosimetry services that transmit the dose records about individual radiation monitoring to the Radiation Protection Register of the Federal Office for Radiation Protection (BfS). The purpose of the Radiation Protection Register is to supervise the keeping of the dose limits and to monitor the compliance with the radiation protection principle ''Optimisation'' by performing detailed annual statistical analyses of the monitored persons and their radiation exposure. The annual report of the Radiation Protection Register provides information about status and development of occupational radiation exposure in Germany. In 2012, about 350,000 workers were monitored with dosemeters for occupational radiation exposure. The number increased continuously by totally 10 % into the past five years. 19 % of the monitored persons received measurable personal doses. The average annual dose of these exposed workers was 0.52 mSv corresponding to 2.6 % of the annual dose limit of 20 mSv for radiation workers. In total, 2 persons exceeded the annual dose limit of 20 mSv, i.e. less than one case per 100,000 monitored persons. The collective dose of the monitored persons decreased to 27.9 Person-Sv, the lowest value since the last fifty years of occupational dose monitoring. 45 airlines calculated the route doses of 40,000 aircraft crew members by using certified computer programmes for dose calculation and sent the accumulated monthly doses via the Federal Office for Civil Aviation (''Luftfahrt-Bundesamt, LBA'') to the BfS. The collective dose of the aircraft crew personnel is 78.5 person- Sv, and thus significantly higher than the total collective dose of the workers monitored with personal dosemeters. The annual average dose of aircraft crew personnel was 1.96 mSv and decreased compared to 2011 (2.12 mSv) due to solar cycle. In 2012, about

  4. Development of a job-exposure matrix for veterinary doctors for the estimation of ionizing radiation exposure during diagnosis using X-ray devices in the veterinary medicine; Entwicklung einer ''Job-Exposure-Matrix'' fuer Tieraerzte zur Abschaetzung der Exposition an ionisierender Strahlung bei der Diagnose mit Hilfe von Roentgengeraeten in der tieraerztlichen Praxis

    Energy Technology Data Exchange (ETDEWEB)

    Feige, S.; Kaulard, J.; Mergel, E. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koeln (Germany)

    2012-02-15

    Subject of the current project ''3605S04477 - Entwicklung einer ''Job-Exposure-Matrix'' fuer Tieraerzte zur Abschaetzung der Exposition an ionisierender Strahlung bei der Diagnose mit Hilfe von Roentgengeraeten in der tieraerztlichen Praxis'' is the analysis of the radiation exposure of medical staff due to diagnostic x-ray examinations in veterinary medicine. In detail the radiation exposure of the medical staff will be first measured and next will be analysed and transformed into a data structure, which allows an easy estimation of the radiation exposure of the medical staff due to the future execution of diagnostic x-ray examination. The measurements, this data structure (called ''Job-Exposure-Matrix'') is based on, will be taken primarily during examinations performed at two veterinary clinics of the ''Freie Universitaet Berlin (FU Berlin)'', which are linked to the project. In addition some further measurements are taken at four veterinary clinics in Germany. Finally, for some examinations measurements are performed using phantoms set up of dead animals. Due to the shielding of the x-ray protective clothing and the resulting very low values the doses are measured in front of the protective clothing. Primarily, electronic personal dosemeters are used, complemented by thermoluminescence dosemeters and an ionisation radiation chamber. The measurement and the related analysis show, that the exposure of the medical staff due to the scattered Roentgen beam during a single x-ray examination is low. However, a high frequency of examinations during a year may result in no more marginal exposure which in addition might exceed the relevant dose limits. Thus, the measurements also emphasize the importance of radiation shielding even in case of low exposure due to a single x-ray examination. The compilation of the measured data in the data structure allows an easy estimation of the radiation

  5. Personal dose equivalent conversion coefficients for photons to 1 GeV.

    Science.gov (United States)

    Veinot, K G; Hertel, N E

    2011-04-01

    The personal dose equivalent, H(p)(d), is the quantity recommended by the International Commission on Radiation Units and Measurements (ICRU) to be used as an approximation of the protection quantity effective dose when performing personal dosemeter calibrations. The personal dose equivalent can be defined for any location and depth within the body. Typically, the location of interest is the trunk, where personal dosemeters are usually worn, and in this instance a suitable approximation is a 30 × 30 × 15 cm(3) slab-type phantom. For this condition, the personal dose equivalent is denoted as H(p,slab)(d) and the depths, d, are taken to be 0.007 cm for non-penetrating and 1 cm for penetrating radiation. In operational radiation protection a third depth, 0.3 cm, is used to approximate the dose to the lens of the eye. A number of conversion coefficients for photons are available for incident energies up to several megaelectronvolts, however, data to higher energies are limited. In this work, conversion coefficients up to 1 GeV have been calculated for H(p,slab)(10) and H(p,slab)(3) both by using the kerma approximation and tracking secondary charged particles. For H(p)(0.07), the conversion coefficients were calculated, but only to 10 MeV due to computational limitations. Additionally, conversions from air kerma to H(p,slab)(d) have been determined and are reported. The conversion coefficients were determined for discrete incident energies, but analytical fits of the coefficients over the energy range are provided. Since the inclusion of air can influence the production of secondary charged particles incident on the face of the phantom, conversion coefficients have been determined both in vacuo and with the source and slab immersed within a sphere in air. The conversion coefficients for the personal dose equivalent are compared with the appropriate protection quantity, calculated according to the recommendations of the latest International Commission on Radiological

  6. Measurement of conversion coefficients between air Kerma and personal dose equivalent and backscatter factors for diagnostic X-ray beams; Determinacao experimental dos coeficientes de conversao de Kerma no ar para o equivalente de dose pessoal, Hp(d), e fatores de retroespalhamento em feixes de raios-x diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Rosado, Paulo Henrique Goncalves

    2008-07-01

    Two sets of quantities are import in radiological protection: the protection and operational quantities. Both sets can be related to basic physical quantities such as kerma through conversion coefficients. For diagnostic x-ray beams the conversion coefficients and backscatter factors have not been determined yet, those parameters are need for calibrating dosimeters that will be used to determine the personal dose equivalent or the entrance skin dose. Conversion coefficients between air kerma and personal dose equivalent and backscatter factors were experimentally determined for the diagnostic x-ray qualities RQR and RQA recommended by the International Electrotechnical Commission (IEC). The air kerma in the phantom and the mean energy of the spectrum were measured for such purpose. Harshaw LiF-100H thermoluminescent dosemeters (TLD) were used for measurements after being calibrated against an 180 cm{sup 3} Radcal Corporation ionization chamber traceable to a reference laboratory. A 300 mm x 300 mm x 150 mm polymethylmethacrylate (PMMA) slab phantom was used for deep-dose measurements. Tl dosemeters were placed in the central axis of the x-ray beam at 5, 10, 15, 25 and 35 mm depth in the phantom upstream the beam direction Another required parameter for determining the conversion coefficients from was the mean energy of the x-ray spectrum. The spectroscopy of x-ray beams was done with a CdTe semiconductor detector that was calibrated with {sup 133} Ba, {sup 241} Am and {sup 57} Co radiation sources. Measurements of the x-ray spectra were carried out for all RQR and RQA IEC qualities. Corrections due to the detector intrinsic efficiency, total energy absorption, escape fraction of the characteristic x-rays, Compton effect and attenuation in the detector were done aiming an the accurate determination of the mean energy. Measured x-ray spectra were corrected with the stripping method by using these response functions. The typical combined standard uncertainties of

  7. Realization of radiobiological in vitro cell experiments at conventional X-ray tubes and unconventional radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Beyreuther, Elke

    2010-09-10

    More than hundred years after the discovery of X-rays different kinds of ionizing radiation are ubiquitous in medicine, applied to clinical diagnostics and cancer treatment as well. Irrespective of their nature, the widespread application of radiation implies its precise dosimetric characterization and detailed knowledge of the radiobiological effects induced in cancerous and normal tissue. Starting with in vitro cell irradiation experiments, which define basic parameters for the subsequent tissue and animal studies, the whole multi-stage process is completed by clinical trials that translate the results of fundamental research into clinical application. In this context, the present dissertation focuses on the establishment of radiobiological in vitro cell experiments at unconventional, but clinical relevant radiation qualities. In the first part of the present work the energy dependent biological effectiveness of photons was studied examining low-energy X-rays (≤ 50 keV), as used for mammography, and high-energy photons (≥ 20 MeV) as proposed for future radiotherapy. Cell irradiation experiments have been performed at conventional X-ray tubes providing low-energy photons and 200 kV reference radiation as well. In parallel, unconventional quasi-monochromatic channeling X-rays and high-energy bremsstrahlung available at the radiation source ELBE of the Forschungszentrum Dresden-Rossendorf were considered for radiobiological experimentation. For their precise dosimetric characterization dosimeters based on the thermally stimulated emission of exoelectrons and on radiochromic films were evaluated, whereas just the latter was found to be suitable for the determination of absolute doses and spatial dose distributions at cell position. Standard ionization chambers were deployed for the online control of cell irradiation experiments. Radiobiological effects were analyzed in human mammary epithelial cells on different subcellular levels revealing an increasing amount

  8. Monte Carlo simulations and dosimetric studies of an irradiation facility

    Science.gov (United States)

    Belchior, A.; Botelho, M. L.; Vaz, P.

    2007-09-01

    There is an increasing utilization of ionizing radiation for industrial applications. Additionally, the radiation technology offers a variety of advantages in areas, such as sterilization and food preservation. For these applications, dosimetric tests are of crucial importance in order to assess the dose distribution throughout the sample being irradiated. The use of Monte Carlo methods and computational tools in support of the assessment of the dose distributions in irradiation facilities can prove to be economically effective, representing savings in the utilization of dosemeters, among other benefits. One of the purposes of this study is the development of a Monte Carlo simulation, using a state-of-the-art computational tool—MCNPX—in order to determine the dose distribution inside an irradiation facility of Cobalt 60. This irradiation facility is currently in operation at the ITN campus and will feature an automation and robotics component, which will allow its remote utilization by an external user, under REEQ/996/BIO/2005 project. The detailed geometrical description of the irradiation facility has been implemented in MCNPX, which features an accurate and full simulation of the electron-photon processes involved. The validation of the simulation results obtained was performed by chemical dosimetry methods, namely a Fricke solution. The Fricke dosimeter is a standard dosimeter and is widely used in radiation processing for calibration purposes.

  9. Estimate of worker and patient exposures and quality control in hysterosalpingography exams; Estimativa da exposicao de pacientes e trabalhadores e controle de qualidade em exames de histerossalpingografia

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Barbara Beatriz Dias

    2006-06-15

    Hysterosalpingography (HSG) is a relatively frequent radiological procedure, which is used to access and study the uterine cavity and the tubary permeability. The estimate of the radiation doses received by the patients, and of the associated risks, has become of great interest in recent years. The importance in evaluating the received doses becomes even higher when the gonads region is irradiated; as in the case of hysterosalpingography, where the patients are relatively young, existing a high probability of future pregnancy. In HSG procedure the physician stays beside the patient, being also exposed. The purpose of this study was to analyze, during HSG procedures, the exposition of patients, measuring the kerma-area (P{sub K,A}) product by using an ionization chamber of big area, to evaluate the doses received by the radiologist using thermoluminescent dosemeters and to evaluate the quality of image by means of qualitative methods. The results gotten during the accompaniment of 86 examinations had been the following ones: the average P{sub K,A} was 706 {+-} 388 cGy.cm{sup 2}, to an average exposition time of 2 {+-} 1 minutes. In order to optimize the exposure of patients and workers, the time of scopy and the number of images should be reduced, whenever it is possible. Due to the significant values of equivalent dose received by the lens, the use of plumbiferous eyeglasses is recommended. (author)

  10. Compact fluorescent lamp phosphors in accidental radiation monitoring.

    Science.gov (United States)

    Murthy, K V R; Pallavi, S P; Ghildiyal, Rahul; Parmar, Manish C; Patel, Y S; Ravi Kumar, V; Sai Prasad, A S; Natarajan, V; Page, A G

    2006-01-01

    The application of lamp phosphors for accidental dosimetry is a new concept. Since the materials used in fluorescent lamps are good photo luminescent materials, if one can either use the inherent defects present in the phosphor or add suitable modifiers to induce thermoluminescence (TL) in these phosphors, then the device (fluorescent lamp) can be used as an accidental dosemeter. In continuation of our search for a suitable phosphor material, which can serve both as an efficient lamp phosphor and as a good radiation monitoring device, detailed examination has been carried out on cerium and terbium-doped lanthanum phosphate material. A (90)Sr beta source with 50 mCi strength (1.85 GBq) was used as the irradiation source for TL studies. The TL response as a function of dose received was examined for all phosphors used and it was observed that the intensity of the TL peak vs. dose received was a linear function in the dose range 0.1-200 Gy in each case. Incidentally LaPO(4): Ce,Tb is a component of the compact fluorescent lamp marketed recently as an energy bright light source. Besides having very good luminescence efficiency, good dosimetric properties of these phosphors render them useful for their use in accidental dosimetry also.

  11. X-rays spectrum and air Kerma during a mammography study; Espectro de los rayos X y Kerma en aire durante un estudio mamografico

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez G, J. [Instituto Nacional de Estadistica Geografia e Informatica, Av. Heroes de Nacozari Sur 2301, Fracc. Jardines del Parque, 20276 Aguascalientes (Mexico); Hernandez V, R.; Hernandez D, V. M.; Vega C, H. R. [Unidad Academica de Estudios Nucleares, Universidad Autonoma de Zacatecas, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)], e-mail: fermineutron@yahoo.com

    2009-10-15

    In this calculation series was modeled the source of electrons, the target and the filter. Using thermoluminescent dosemeters of ZrO{sub 2}+PTFE the air Kerma was measured in five points located on a phantom made with acrylic and water when it was exposed to a X-rays beam produced by electrons of 24 KeV and 10 m A of current that produces a mammography. The air Kerma values at the entrance surface of the phantom were compared with values calculated by Monte Carlo methods. The air Kerma values measured indicate that approximately the five points receive the same air Kerma, what means that the beam is homogeneous, of the Monte Carlo calculations we find that the center receives a greater dose what implies that the beam is not uniform, the explanation of this fact is attributed to was used a simple model in the calculations, nevertheless, the air Kerma average measured at the entrance surface of the phantom was of 0.96 +{sub -} 0.03 m G, while the other obtained by the calculations was of 0.96 +{sub -} 0.06 mGy, to compare both do not exist significant differences. (author)

  12. Determination of the Neutron and Photon Dose Equivalent at Work Places in Nuclear Facilities of Sweden. An SSI - EURADOS comparison exercise. Part 1: Measurements and Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Klein, H.; Lindborg, L. [eds.

    1995-08-01

    A large-scaled measurement program of neutron and photon dose equivalent rates was organized in 1992 and 1993 at the nuclear power plant at Ringhals and at the Swedish Central Interim Storage Facility for spent fuel elements at Oskarshamn. The aim was to evaluate the uncertainty in these kinds of measurements in realistic radiation fields. For that purpose, groups experienced with different techniques and - in some cases - several groups with a particular technique, were invited to take part. Besides traditional rem counters, the following categories of instruments were involved: Bonner spheres systems, proton recoil detectors, tissue equivalent proportional counters, super heated drop detectors, GM counters and different types of personal dosemeters. Part I reports all initial results as presented by the individual participants as well as a first compilation of the results. A later report, Part II, will give detailed analysis of the results. The conclusions will be published in the journal Radiation Protection Dosimetry. Separate abstracts have been prepared for all 14 papers.

  13. Assessment of dose in thyroid and salivary glands in dental radiology using thermoluminescent dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Mantuano, Natalia de O.; Silva, Ademir X. da [Instituto Alberto Luiz Coimbra de Pos-Graduacao e Pesquisa em Engenharia (PEN/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear; Canevaro, Luca V.; Mauricio, Claudia Lucia P. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ) Rio de Janeiro, RJ (Brazil); Correa, Samanda C.A., E-mail: scorrea@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Radiobiological and epidemiological studies have provided evidence of risk of salivary and thyroid glands tumors incidence associated with oral radiology. Based on these studies, the tissue weighting factors were reviewed by the International Commission on Radiological Protection (ICRP) in 2007. The main objective of the present work is to estimate the absorbed dose on thyroid and salivary glands (parotid, submandibular and sublingual), during a complete periapical examination. The complete periapical examination was simulated using a Spectro 70X Seletronic X-ray dental equipment on an Alderson Rando phantom with Harshaw LiF:Mg,Ti thermoluminescent dosemeters (TLD100). A PTW DIADOS dosimetric system was used for calibration. The TLD100 were inserted into the phantom slices corresponding to the organs of interest. During a complete periapical examination, the highest evaluated mean absorbed dose was 4.9 mGy in the right submandibular gland and the lowest one of 1.5 mGy in the left thyroid lobe. Entrance surface doses ranged from 2.1 to 2.6 mGy, measured, respectively, for the techniques of upper left molar and lower right molar. When compared with the diagnostic reference levels (DRL), the entrance surface doses values were lower than the DRLs recommended in Brazilian current legislation. However, the dosimetric results show the need of optimization for complete periapical examination to minimize patient exposure. Measurements were performed without the use of thyroid protectors. The use of this device is certainly an easy and simple method of dose reduction. (author)

  14. Chromogene properties of the betalains before gamma photons; Propiedades cromogenas de las betalainas ante fotones gamma

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez N, S.; Quintero M, C. L. [Universidad Autonoma de Zacatecas, Unidad Academica de Ciencias Quimicas, Programa de Quimica en Alimentos, Km. 0.5 Carretera a Guadalajara Ejido La Escondida, Zacatecas (Mexico); Vega C, H. R., E-mail: srneri@hotmail.co [Universidad Autonoma de Zacatecas, Unidad Academica de Ciencias Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2010-09-15

    The coloration changes of four natural extracts in function of the absorbed dose produced by a gamma rays source of {sup 137}Cs have been studied. The natural extracts were obtained of tuna varieties that contain betalains that are natural pigments of some plants as the beet of where is derived its name. These also are found in abundant form in the fruits of some species of opuntia genus (tunas). The extracts were obtained by maceration, starting from beet and three tuna varieties that were stabilized to a p H of 5.5. The extracts were exposed to the gamma rays of a {sup 137}Cs source and the change in the coloration was observed by means of an ultra violet/visible spectrophotometer through of the absorption of the samples to photons of wave longitude 535 nm. The absorption was measured, to different time intervals. The relation between the absorbed dose in D{sub w} water and the chromogene properties of the pigment was established, with the intention of using it as possible dosemeter. (Author)

  15. Use of radiation and radiation practices in 1993. Events and statistics

    Energy Technology Data Exchange (ETDEWEB)

    Havukainen, R. [ed.

    1994-05-01

    In the end of the year 1993 there were in force 1740 safety licences for the use of radiation granted by the Finnish Centre for Radiation and Nuclear Safety (STUK). In addition to this there were 2100 places for dental x-ray activities in Finland. All together 12726 radiation sources and 313 radioisotope laboratories were in use. The import of radioactive substances was 3.9 x 10 {sup 15} Bq and the export 2.5 x 10 {sup 13} Bq. The production of short-lived isotopes was 1.3 x 10 {sup 13} Bq. The monitoring of personal radiation doses was organized for 11171 workers and 1299 working places. The annual dose (the integrated readings of dosemeters) was greater than registration threshold for 24% of workers. The collective dose (the sum of the results of the dose measurements) registered to the Finnish Dose Register was 6.9 manSv; 74% belonged to the workers of nuclear power plants. The sum of the personal doses measured in 1993 were for three interventional radiologists and fifteen workers in nuclear power plants 20 mSv or more. The effective doses were in each case under the annual dose limit of 50 mSv. The effective doses for the interventional radiologists were under 20 mSv. (7 figs., 16 tabs.).

  16. Use of active dosimeters as tool for optimization in hemodynamics; Uso de dosimetros ativos como ferramenta de otimizacao em hemodinamica

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Rafael; Pereira, Dirceu D., E-mail: rafael@bolsista.ird.gov.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Fisica; Canevaro, Lucia V. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Rodrigues, Barbara B.D. [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Ferreira, Esmeralci [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Faculdade de Medicina. Servico de Hemodinamica

    2016-07-01

    Interventional cardiology procedures are, in general, associated with high doses to patients and professionals. The objective of this study is to measure the radiation levels received by the staff. The professional dosimetry was performed in a department of Hemodynamics of University Hospital in Rio de Janeiro, were followed 331 coronary angiography (CA) and 26 percutaneous transluminal coronary angioplasty (PTCA) procedures. In order to measure the radiation levels at the chest of interventional professionals outside of lead aprons, active dosemeters were used. The results show that average personal equivalent dose of doctors, per procedure was 100μSv e 154 μSv. On average, nursing technicians and radiographers receive 12% and 10% of doses of physicians, respectively, during CA and PTCA procedures. From the results, it appears that the doses of hemodynamicists could exceed the annual dose limit of the standards, if radiological protection conduct would not be applied. The use of lead shielding has showed as an effective action to reduce doses in these workers. (author)

  17. Dose in thorax X-ray; Dosis en radiografia de torax

    Energy Technology Data Exchange (ETDEWEB)

    Pinedo S, A.; Hernandez O, M.; Duran M, H. A.; Gonzalez G, R.; Guerra M, J. A.; Hernandez D, V. M.; Salas L, M. A.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Rivera M, T. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Av. Legaria 694, 11500 Mexico D. F. (Mexico); Azorin N, J. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, 09340 Mexico D. F. (Mexico)], e-mail: lare_56@hotmail.com

    2009-10-15

    The entrance dose that a patient receives during a radiological study of thorax was measured, these measures were realized with thermoluminescent dosemeters of CaSO{sub 4}:Dy, placed in paraffin phantom. The radiation control in diagnostic radiology should be an important element during each radiological procedure. Current studies suggest that even low dose of X-rays used in routine diagnostic procedures can give space to a small incidence of latent damaging effects in patient. The irradiation of thoracic region is more studied through the conventional radiology, method that continues occupying the first place like diagnostic in several pathologies it generates images of heart, lungs, spine, etc. As well as, allow to observe the location of catheters, subclavian s, nasogastric sound, endotracheal tubes and umbilical catheters. The dose magnitude that is received during the realization of this study type is not usually measured, since the main concern is to have a good image to make a good diagnostic. The measures were realized using equipment parameters that were defined on experience of radiologist technician. The work was realized in the living room 1 of X-rays service of General Hospital of Zone No. 1 of IMSS in Zacatecas. The obtained results demonstrated that irradiation field is not uniform and that in any point where the dose was measured it is not exceeded to that established by the Mexican Official Standard-157-SSA-1996 for a study of thorax X-ray. (Author)

  18. A preliminary comparison of total skin electron treatment techniques to demonstrate the application of a mid-torso phantom for measurement of dose penetration.

    Science.gov (United States)

    Baugh, G; Al-Alawi, T; Fletcher, C L; Mills, J A; Grieve, R J

    2011-12-01

    In the UK, the treatment of patients with mycosis fungoides using total skin electron (TSE) beam therapy is undertaken using a number of different irradiation techniques. As part of a review of these techniques, a comparative set of measurements would be useful to determine how the techniques differ in terms of dose distribution. A dose penetration intercomparison method that could be used as part of such a study is presented here. The dose penetrations for six treatment techniques currently or recently used in four centres in the UK were measured. The variation of dose with skin depth was measured in a WT1 solid water mid-torso phantom. The phantom is portable and suitable to be used in all the techniques. It is designed to hold four small radiochromic film dosemeters to investigate the variation in dose around the mid-torso. For each treatment technique, the phantom was irradiated using the clinical set-up. The phantom performed well and was able to measure dose penetration and the uniformity of penetration for several treatment techniques. These preliminary results demonstrate that there is some variation in dose distribution between different TSE treatment techniques and that the phantom could be used in a more comprehensive intercomparison. The results are not intended to demonstrate comprehensively the range of penetration that can be achieved in clinical practice as, for one of the treatment techniques, the penetration is customised for the extent of the disease.

  19. The Pelletron Accelerator of IFUNAM and its possible applications to the dosimetry; El Acelerador Pelletron del IFUNAM y sus posibles aplicaciones a la dosimetria

    Energy Technology Data Exchange (ETDEWEB)

    Rickards, J. [Instituto de Fisica, UNAM, Circuito Exterior, C.U. 04510 Mexico D.F. (Mexico)

    1999-07-01

    The Pelletron Accelerator of positive ions 3 MV in the Institute of Physics of UNAM has characteristics that make it useful for the application to the radiations dosimetry. It is ideal for studying the detailed mechanisms of the radiation interaction with matter, therefore it can be applied to know the performance of dosemeters. With this device can be accelerated almost any type of ion, including He, but excepting the others noble gases. The energies of the disposable ions are in the interval 1 MeV until several MeV, depending of the state of charge selected, the energy can be varied continuously with accuracy of some KeV. It can be achieved streams from 10{sup 4} until 10{sup 6} ions/cm{sup 2}, allowing studies of individual events (tracks) or of collective processes. the beam size can be varying from a diameter 1 mm until 5 cm. It is also took in account with detectors and other techniques associated that can be combined for supporting studies, as surface barrier detectors and of other types, as well as the RBS, PIXE, RN techniques and channeling. (Author)

  20. Photon and neutron doses of the personnel using moisture and density measurement devices

    Energy Technology Data Exchange (ETDEWEB)

    Carinou, E.; Papadomarkaki, E.; Tritakis, P.; Hourdakis, C.I.; Kamenopoulou, V. [Greek Atomic Energy Commission, Agia Paraskevi, Attiki, 60092 (Greece)

    2006-07-01

    The objective of this study is to present the evolution of the photon doses received by the workers who use mobile devices for measuring the moisture and the density in various materials and to estimate the neutron doses. The workers employed in more than 30 construction companies in Greece were 76 in 2004. The devices used for that purpose incorporate a {sup 137}Cs source for density measurements and an {sup 241}Am-Be source for moisture measurements of soil, asphalt or concrete. Photon and neutron measurements were performed occasionally during the on site inspections. The results of the measurements showed that the photon and neutron dose rates were not negligible. The workers were monitored for photon radiation using film badges (Kodak Type 2, Holder NRPB type) till the year 2000 and then TLD badges issued by the Greek Atomic Energy Commission (GAEC), on a monthly basis. Since the neutron dose rates measured by a rem-meter were not so high, no neutron dosemeters were issued for them. Their personal dose equivalent data for photons are kept in the National Dose Registry Information System (N.D.R.I.S.) in G.A.E.C. and were used for statistical analysis for the period from 1997 till 2004. As far as the neutrons are concerned, a Monte Carlo code was used to simulate the measuring devices and the working positions in order to calculate the neutron individual doses. (authors)

  1. Preliminary results of quality assurance implementation in interventional cardiology

    Energy Technology Data Exchange (ETDEWEB)

    Nikodemova, D. [Slovak Medical Univ., Bratislava (Slovakia)

    2006-07-01

    Full text of publication follows: The dramatic increase in the frequency of the interventional procedures reflects the significant benefit which directly affects the patient. However parallel is this benefit accompanied by some concern about the consequent increase in doses to patient and staff. The question of safety has prompted the European commission and Who to issue and advise to conduct research in the area of the intervention radiology and to prepare standard protocols for quality assurance of interventional procedures. The presentation is focused on the optimization of interventional procedures in cardiology with aim to reduce the risk level of high exposures and to elaborate national standard methods of quality assurance program, as well as, the procedures used for the case of overexposure. Study was conducted at Slovak Institute of Cardiology, as well as, at Slovak Pediatric Cardiology Center, where wide variation of specific interventional procedures are performed. Skin dose date of patient were measured by Unfors Patient Skin Dosemeter P.S.D. - 4 and the values of Dose area products followed during all examinations. All technical parameters used for examinations were identified. Simultaneously were measured the personal doses of the medical staff present by the examinations. For personal dose measurements Unfors E.D.D.30 dose meter was used, as well as, T.L.D. for measurements of doses on extremities. Preliminary results confirm wide spread of patient doses and professional doses of medical staff. The causes of this spread will by discussed. (authors)

  2. Cosmic Radiation Measurements in Airline Service

    Energy Technology Data Exchange (ETDEWEB)

    Bagshaw, M

    1999-07-01

    Ionising radiation monitoring equipment is installed in all Concordes and much data have been derived. To validate the measurements from the on-board monitoring equipment, a programme of measurements on Concorde has been carried out using passive dosemeters in association with the UK National Radiological Protection Board. Data from a typical month (in this case October 1997) shows an arithmetic mean dose across the British Airways Concorde fleet of 12.9 ({+-}0.4) {mu}Sv.h{sup -1}. Results from the NRPB measurements for the same month give a dose of 11.4 ({+-}0.5) {mu}Sv.h{sup -1} and application of the CARI 3Q programme gives a dose of 9.6 {mu}Sv.h{sup -1} for the same month. The effective route dose between London and New York gives a mean value of 43.1 {mu}Sv for the Concorde detectors. The NRPB results give a route dose of 38.9 {mu}Sv whereas the CARI 3Q programme gives a route dose of 32.5 {mu}Sv. Measurements have also been performed on the Boeing 747-400 aircraft on the high latitude ultralonghaul direct London-Tokyo flight and these give values in the region of 6 {mu}Sv.h{sup -1}, against the CARI 3Q estimate of 3.7 {mu}Sv.h{sup -1}. (author)

  3. TL dosimetry in the new Tandetron ion accelerator site of the National Institute of Nuclear Research (ININ); Dosimetria TL en el area del nuevo acelerador de iones Tandetron del ININ

    Energy Technology Data Exchange (ETDEWEB)

    Valdovinos A, M.; Gonzalez M, P.R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    The National Institute of Nuclear Research (ININ) acquired a positive ions accelerator type Tandetron 2 MV of the dutch company High Voltage Engineering, Europe B.V., which was finished its installation this year (2000) in an already existing building in the Dr. Nabor Carrillo Flores Nuclear Centre, where it was prepared for the following purposes: the accelerator will be used to realize research through X-ray emission induced by charged particles, Rutherford backscattering analysis, nuclear reaction analysis, gamma ray emission induced by charged particles, resonant dispersion analysis, elastic backward detection analysis and by particle canalization analysis. The accelerator consists of an injection system with two ion sources, ion accelerator tank with voltage in terminal at 2 MV, recovery and recirculation system of charge interchange gas, iman selector analyzer system and with high energy focussing, control system through computer and management and recovery of isolator gas system. For the realization of operation tests of this accelerator, it was had the license authorizing by the National Commission of Nuclear Safety and Safeguards (CNSNS). During the test stage Tl dosemeters were arranged in the Tandetron accelerator area, and also in direction to the beam outlet. In this work, are presented the obtained results of the measurement of radiation levels, as in the area as in the beam outlet. (Author)

  4. Evaluation of radiological protection and dose of skin entrance in paediatric dentistry examinations; Avaliacao da protecao radiologica e da dose de entrada na pele em exames de odontologia pediatrica

    Energy Technology Data Exchange (ETDEWEB)

    Khoury, Helen Jamil [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Vasconcelos, Flavia Maria Nassar de [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Silveira, Marcia Maria Fonseca da [Universidade de Pernambuco (UPE), Recife, PE (Brazil). Fac. de Odontologia; Couto, Geraldo Bosco Lindoso [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Fac. de Odontopediatria; Brasileiro, Izabela Vanderley

    2005-07-01

    In this work the radiological protection conditions and dose at the entrance of pediatric patients undergoing dental intraoral radiographs were evaluated. The study was conducted in two clinics of the dentistry course at the Federal University of Pernambuco, Recife, PB, Brazil, equipped with conventional X-ray apparatus, with 60 and 70 kV. 254 exams of 113 patients between the ages of 3 to 12 years were evaluated. The skin entrance dose was estimated using TLD-100 thermoluminescent dosemeters. During the examination were also recorded information regarding the time of exposure, radiographic technique used, use of thyroid protectors and lead apron, angle and distance of the cone Locator to the patient's skin. The results showed that the input skin doses ranged from 0.3 mGy to 10mGy. The lead apron was used in 71% of exams while the thyroid shield was only used in 58% of the exams. The exposure times ranged from 0,5s to 1,5s. From the results it can be concluded that the radiological procedures are not optimized and that in some cases the patient dose is high.

  5. Verification of the dose in the inspection modules of Co-60 from Mexicali, B.C.N. through thermoluminescent dosimetry; Verificacion de la dosis en los modulos de inspeccion de Co-60 de Mexicali, B.C. mediante dosimetria termoluminiscente

    Energy Technology Data Exchange (ETDEWEB)

    Cruz C, D.; Azorin, J.; Rivera, T. [UAM-I, 09340 Mexico D.F. (Mexico)

    2005-07-01

    On the February and April 2005 months, there entered in operation two inspection modules, in the mexican border city of Mexicali. B.C.N., those which they work based on gamma rays, emitted by sources of {sup 60} Co; this fact generate a concern, on the part of the population of this city. Soon after these events, a group of personages of the local politics, they began a campaign, in favor of closing these modules, based on the supposition, of that the emitted radiation by these sources, represents a danger for health of people that uses the international crossing located to a side of the porter lodge 1, as well as of the population in general. As service to the community border of Mexico specifically to the population of Mexicali, B.C.N. city, inhabitants of this city, municipal, state and federal authorities and, the outstanding preoccupation of the Republic Senate (Commission of Border Affairs), the National Commission of Nuclear Security and Safeguards (CNSNS) they requested the support of the Metropolitan Autonomous University (UAM) and of the National Polytechnic Institute (IPN) to verify the radiation levels in the facilities of the sources of {sup 60} Co of the porter lodges of Mexicali-Calexico proceeding to the monitoring of this facilities in the period of 14-17 June 2005, 17 using thermoluminescent dosemeters elaborated in Mexico. (Au0010th.

  6. Impact of radiation protection means on the dose to the lens of the eye while handling radionuclides in nuclear medicine.

    Science.gov (United States)

    Bruchmann, Iris; Szermerski, Bastian; Behrens, Rolf; Geworski, Lilli

    2016-12-01

    The human eye lens appears to be more radiosensitive than previously assumed. The reduction of the limit for the dose to the lens of the eye to 20 mSv per year has been passed in the current Euratom Directives (2013). Therefore, in this work the impact of laboratory glasses and X-ray protective goggles was investigated and reciprocal attenuation factors (i.e. transmission factors) for different nuclides (Tc-99m, I-131, Y-90, F-18 and Ga-68) were determined. The radionuclides in typical geometry (syringe, applicator) were positioned at a distance of 50 cm to the eyes of four Alderson-Head-Phantoms. Different dosemeters measuring Hp(3) respective Hp(0.07) were fixed to the eyes of the phantoms, either behind the glasses or without any protection means, respectively. The mean reciprocal attenuation factors were determined to be between unity for F-18 and I-131 using laboratory glasses (no attenuation effect) and radiation protection means, especially for those dose-relevant beta radiation emitting nuclides such as Y-90. Copyright © 2015. Published by Elsevier GmbH.

  7. Radiation protection in fixed PET/CT facilities—design and operation

    Science.gov (United States)

    Peet, D J; Morton, R; Hussein, M; Alsafi, K; Spyrou, N

    2012-01-01

    We describe the design of a fixed positron emission tomography (PET)/CT facility and the use of a simulated instantaneous dose-rate plot to visually highlight areas of potentially high radiation exposure. We also illustrate the practical implementation of basic radiation protection principles based on the use of distance and shielding and the minimisation of time spent in hot areas. Staff whole body doses for 4 years are presented with results of an optimisation study analysing the dose arising from the different phases within each study using direct reading dosemeters. The total whole body dose for all staff for each patient fell from 9.5 μSv in the first full year of operation to 4.8 µSv in 2008. The maximum dose to an individual member of staff per patient decreased over the same period from 3.2 to 0.9 µSv. The optimisation study showed that the highest dose was recorded during the injection phase. PMID:21976626

  8. Study on the coefficient of variation in indian personnel monitoring system

    Directory of Open Access Journals (Sweden)

    Chandrasekhar Sneha

    2016-01-01

    Full Text Available The primary parameters for testing an individual monitoring system are standard deviation and the coefficient of variation. The International Electrotechnical Commission (IEC standard 62387-1 recommends testing the coefficient of variation of dosemeters for various doses because the acceptable coefficient of variation changes with the dose level. However, for dose quantity Hp(10, i. e. doses greater than 1.1 mSv, the acceptable limit is 5 % and remains unchanged up to the highest dose in the measurable range. This study was carried out to confirm whether the same is followed in the Indian personnel monitoring system when measuring Hp(10 and also in order to study the variation in the coefficient of variation with a given dose. It was observed that even if the coefficient of variation at doses between 0.1 mSv and 1.1 mSv is lower than the IEC requirement, at higher doses, the same may not be true. In routine monitoring, since the anticipated doses are less than 1 mSv, a monitoring system which performs better than the IEC requirement at these levels of doses is an advantage. However, good performance at said dose levels does not naturally indicate good performance at higher doses.

  9. Characterization of neutron calibration fields at the TINT's 50 Ci americium-241/beryllium neutron irradiator

    Science.gov (United States)

    Liamsuwan, T.; Channuie, J.; Ratanatongchai, W.

    2015-05-01

    Reliable measurement of neutron radiation is important for monitoring and protection in workplace where neutrons are present. Although Thailand has been familiar with applications of neutron sources and neutron beams for many decades, there is no calibration facility dedicated to neutron measuring devices available in the country. Recently, Thailand Institute of Nuclear Technology (TINT) has set up a multi-purpose irradiation facility equipped with a 50 Ci americium-241/beryllium neutron irradiator. The facility is planned to be used for research, nuclear analytical techniques and, among other applications, calibration of neutron measuring devices. In this work, the neutron calibration fields were investigated in terms of neutron energy spectra and dose equivalent rates using Monte Carlo simulations, an in-house developed neutron spectrometer and commercial survey meters. The characterized neutron fields can generate neutron dose equivalent rates ranging from 156 μSv/h to 3.5 mSv/h with nearly 100% of dose contributed by neutrons of energies larger than 0.01 MeV. The gamma contamination was less than 4.2-7.5% depending on the irradiation configuration. It is possible to use the described neutron fields for calibration test and routine quality assurance of neutron dose rate meters and passive dosemeters commonly used in radiation protection dosimetry.

  10. Determination of the dosimetric properties of ZrO{sub 2}: Cu and it use in the ultraviolet radiation dosimetry; Determinacion de las propiedades dosimetricas de ZrO{sub 2}: Cu y su empleo en la dosimetria de la radiacion ultravioleta

    Energy Technology Data Exchange (ETDEWEB)

    Molina P, D. [Centro de Proteccion e Higiene de las Radiaciones, Apdo. Postal 6195, La Habana (Cuba); Olvera T, L.; Azorin N, J.; Barrera S, M.; Soto E, A.M. [UAM-I, Av. San Rafael Atlixco 186, 09340 Mexico D.F. (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria del IPN, Av. Legaria 694, 11500 Mexico D.F. (Mexico)]. e-mail: daniel@cphr.edu.cu

    2006-07-01

    In this work the experimental results of studying the thermoluminescent characteristics (TL) of the zirconium oxide doped with copper (ZrO{sub 2}: Cu) exposed to ultraviolet light of wavelength in the interval of 200-400 nm are presented. The material in powder form was prepared using the sol-gel method. The dosimetric characteristics studied includes the emission curve TL (curved TL), the thermoluminescent response in function of the wavelength, the minimum dose detectable and the lineality of the response. The TL response of the ZrO{sub 2}: Cu in function of the wavelength presents two maxima, in 260 and 290 nm, respectively. The TL curve of the ZrO{sub 2}: Cu showed two peaks, in 120 and 170 C, respectively, being its similar form for all the studied wavelengths. The response in function of the spectral irradiance results to be lineal in the interval from 160 to 2300 mJ/cm{sup 2}. The obtained results when studying the TL properties of ZrO{sub 2}: Cu exposed to the ultraviolet radiation show that it gathers dosimetric characteristics prominent to be used as an ultraviolet radiation dosemeter. (Author)

  11. Study of the dosimetric characteristics of cosmic radiation at civil aviation altitudes

    CERN Document Server

    Ferrari, A; Rancati, T

    2002-01-01

    The dependence of the doses on solar activity for intermediate levels of the solar modulation parameter has been studied by means of simulations carried out by the Monte Carlo transport code FLUKA. The vertical cut-off rigidities investigated lie between 0.4 and 6.1 GV. The calculated results show that the linear dependence proposed in a previous work, for the effective dose rate as a function of the solar modulation parameter, can be considered as an acceptable approximation. In addition, some dosimetric characteristics of cosmic radiation and some properties of the dosemeters in use for monitoring in the cosmic ray environment have been analysed with a view to simplifying measurements. The depth-dose curves in the ICRU sphere and the response of a tissue-equivalent ionisation chamber have been determined by the FLUKA code for a number of cosmic ray spectra. On the basis of the calculated results, it is concluded that a value of the depth, d, which would make the ambient dose equivalent a conservative predic...

  12. Thermoluminescence of Zn{sub 3}(PO{sub 4}){sub 2}:Mn{sup 2+} exposed to β radiation

    Energy Technology Data Exchange (ETDEWEB)

    Perez S, R.; Aceves, R.; Piters D, T.; Rodriguez M, R. [Universidad de Sonora, Departamento de Investigacion en Fisica, Hermosillo, Sonora (Mexico); Camarillo, I. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico); Camarillo, E., E-mail: rperez@cifus.uson.mx [UNAM, Instituto de Fisica, Cicuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2015-10-15

    The thermoluminescence (Tl) response and trapping analysis of Zn{sub 3}(PO{sub 4}){sub 2}:Mn{sup 2+} glass at room temperature after being exposed to a dose of β-irradiation is reported. The material shows a linear behavior for doses lower than 25 Gy. Measurements indicate that Tl glow curves are composed by several glow peaks. In order to verify this observation, partial heating technique has been applied. The result was the detection of at least four glow peaks located about 124, 199, 240, and 290 degrees C. The complete Tl glow curve shows a higher intensity at temperatures near 200 degrees C, which reduce possibilities of fading. A residual Tl analysis for different waiting times in the measurement of Tl indicate that low decay luminescent centers exist which correspond mainly to the first Tl glow peak. According with the result found, this type of material has potential to be used as β-irradiation dosemeter in different applications. (Author)

  13. Novel shielding materials for space and air travel.

    Science.gov (United States)

    Vana, N; Hajek, M; Berger, T; Fugger, M; Hofmann, P

    2006-01-01

    The reduction of dose onboard spacecraft and aircraft by appropriate shielding measures plays an essential role in the future development of space exploration and air travel. The design of novel shielding strategies and materials may involve hydrogenous composites, as it is well known that liquid hydrogen is most effective in attenuating charged particle radiation. As precursor for a later flight experiment, the shielding properties of newly developed hydrogen-rich polymers and rare earth-doped high-density rubber were tested in various ground-based neutron and heavy ion fields and compared with aluminium and polyethylene as reference materials. Absorbed dose, average linear energy transfer and gamma-equivalent neutron absorbed dose were determined by means of LiF:Mg,Ti thermoluminescence dosemeters and CR-39 plastic nuclear track detectors. First results for samples of equal aerial density indicate that selected hydrogen-rich plastics and rare-earth-doped rubber may be more effective in attenuating cosmic rays by up to 10% compared with conventional aluminium shielding. The appropriate adaptation of shielding thicknesses may thus allow reducing the biologically relevant dose. Owing to the lower density of the plastic composites, mass savings shall result in a significant reduction of launch costs. The experiment was flown as part of the European Space Agency's Biopan-5 mission in May 2005.

  14. Exposure from Appliances (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

    Cartwright, R.A

    1999-07-01

    The dosemeter studies on exposures to ELF electromagnetic irradiation from domestic equipment all suggest the whole-body doses are low, whilst some exposure to extremities could be high but of brief duration. Old style electric overblankets, however, are an exception and produce high fields and relatively high whole-body doses if switched on during the night. Relatively few epidemiological studies have addressed these issues. All of the studies have associated problems of interpretations. Two isolated studies throw up on association with the frequency of spontaneous abortion and electric blanket use whilst another links adult AML and electric shaver usage. Both results could be fortuitous. More consistency appears from three studies of childhood leukaemia. Here statistically significant associations between electric blanket use in pregnancies appear in two separate studies, as does hair dryer use in the case of children: other appliances use associations have been reported. These results are critically assessed. The United Kingdom Childhood Cancer Study (UKCCS) addresses some of these issues as part of a wider ranging assessment of EMF at home and at school. External sources are incorporated with the measurement of domestic ambient conditions in an attempt to make an overall assessment of total exposure. (author)

  15. Criticality accident dosimetry systems: an international intercomparison at the SILENE reactor in 2002.

    Science.gov (United States)

    Médioni, R; Asselineau, B; Verrey, B; Trompier, F; Itié, C; Texier, C; Muller, H; Pelcot, G; Clairand, I; Jacquet, X; Pochat, J L

    2004-01-01

    In criticality accident dosimetry and more generally for high dose measurements, special techniques are used to measure separately the gamma ray and neutron components of the dose. To improve these techniques and to check their dosimetry systems (physical and/or biological), a total of 60 laboratories from 29 countries (America, Europe, Asia) participated in an international intercomparaison, which took place in France from 9 to 21 June 2002, at the SILENE reactor in Valduc and at a pure gamma source in Fontenay-aux-Roses. This intercomparison was jointly organised by the IRSN and the CEA with the help of the NEA/OCDE and was partly supported by the European Communities. This paper describes the aim of this intercomparison, the techniques used by the participants and the two radiation sources and their characteristics. The experimental arrangements of the dosemeters for the irradiations in free air or on phantoms are given. Then the dosimetric quantities measured and reported by the participants are summarised, analysed and compared with the reference values. The present paper concerns only the physical dosimetry and essentially experiments performed on the SILENE facility. The results obtained with the biological dosimetry are published in two other papers of this issue.

  16. Radiological protection on interstitial brachytherapy and dose determination and exposure rate of an Ir-192 source through the MCNP-4B; Proteccion radiologica en braquiterapia intersticial y determinacion de la dosis y tasa de exposicion de una fuente de Ir-192 mediante el MCNP-4B

    Energy Technology Data Exchange (ETDEWEB)

    Morales L, M.E. [INEN, Av. Angamos Este 2520- Surquillo, Lima (Peru)

    2006-07-01

    The present work was carried out in the Neurological Sciences Institute having as objective to determine the dose and the rate of exhibition of the sources of Iridium 192, Iodine 125 and Palladium 103; which are used to carry out implant in the Interstitial Brachytherapy according to the TG43. For it we carry out a theoretical calculation, its are defined in the enter file: the geometry, materials of the problem and the radiation source, etc; in the MCNP-4B Monte Carlo code, considering a punctual source and for the dose determination we simulate thermoluminescent dosemeters (TLD): at 5 cm, 50 cm, 100 cm and 200 cm of the source. Our purpose is to analyze the radioprotection measures that should take into account in this Institute in which are carried out brain biopsies using a Micro mar stereotactic mark, and in a near future with the collaboration of a doctor and a cuban physique seeks to be carried out the Interstitial Brachytherapy technique with sources of Ir-192 for patient with tumors like glioblastoma, astrocytoma, etc. (Author)

  17. Dosimetry of a Cesium 137 source; Dosimetria de una fuente de Cesio 137

    Energy Technology Data Exchange (ETDEWEB)

    Torres R, J.G.; Manzanares A, E.; Vega C, H.R. [Unidades Academicas de Estudios Nucleares, Universidad de Zacatecas (Mexico)

    2005-07-01

    It was carried out a dosimetric study of a source of Cesium 137 used in investigations of Radiobiology. This radionuclide has a half life of 30.07 years and it emits photons of 661.657 keV with a probability of 85.2%. The source has been used in a series of experiments trending to observe the cellular response before the gamma rays, as well as for the calibration of equipment of radiological protection. For such reason it is important to determine the dosimetric properties. In this work it was determined the absorbed dose that this source takes when being placed in the center from a methylmethacrylate badge to three distances, 5, 10 and 15 cm. The dose was measured with thermoluminescent dosemeters and it was calculated by means of Monte Carlo method, also was derived an expression that allows to determine the dose starting from the information of the activity of the source and of the distance regarding the same one. (Author)

  18. The MATROSHKA Facility - History and science overview

    Science.gov (United States)

    Reitz, G.; Berger, T.

    The ESA MATROSHKA facility was realized through the German Aerospace Center DLR Cologne as main contractor On the 29th of January 2004 the facility was launched with a Russian PROGRESS vehicle to the International Space Station It was installed outside the Russian segment Zvezda on the 26th February 2004 and remained there until August 2005 and simulates as exact as possible an astronaut during an extravehicular activity EVA The MATROSHKA facility basically consists of a human phantom a Base Structure and a Container The container as well as the phantom is mounted to the base structure which serves as a footprint for the human phantom The container is a Carbon Fiber structure and forms with the Base Structure a closed volume that contains a dry oxygen atmosphere and protects the phantom against e g space vacuum space debris solar UV and material off-gassing It acts also as a simulation of the space suit The phantom body is made of commercial phantom parts well introduced in the field of radiotherapy It consists of 33 slices composed of natural bones embedded in tissue equivalent plastic of different density for tissue and lung The Phantom slices are equipped with channels and cut-outs to allow the accommodation of active and passive dosemeters temperature and pressure sensors The radiation experiments accommodated in the facility are performed under leadership of DLR in a cooperation of more than 15 research institutes from all over the world The MATROSHKA experiments represent therefore the currently biggest international

  19. Radiation protection of staff in 111In radionuclide therapy--is the lead apron shielding effective?

    Science.gov (United States)

    Lyra, M; Charalambatou, P; Sotiropoulos, M; Diamantopoulos, S

    2011-09-01

    (111)In (Eγ = 171-245 keV, t1/2 = 2.83 d) is used for targeted therapies of endocrine tumours. An average activity of 6.3 GBq is injected into the liver by catheterisation of the hepatic artery. This procedure is time-consuming (4-5 min) and as a result, both the physicians and the technical staff involved are subjected to radiation exposure. In this research, the efficiency of the use of lead apron has been studied as far as the radiation protection of the working staff is concerned. A solution of (111)In in a cylindrical scattering phantom was used as a source. Close to the scattering phantom, an anthropomorphic male Alderson RANDO phantom was positioned. Thermoluminescent dosemeters were located in triplets on the front surface, in the exit and in various depths in the 26th slice of the RANDO phantom. The experiment was repeated by covering the RANDO phantom by a lead apron 0.25 mm Pb equivalent. The unshielded dose rates and the shielded photon dose rates were measured. Calculations of dose rates by Monte Carlo N-particle transport code were compared with this study's measurements. A significant reduction of 65 % on surface dose was observed when using lead apron. A decrease of 30 % in the mean absorbed dose among the different depths of the 26th slice of the RANDO phantom has also been noticed. An accurate correlation of the experimental results with Monte Carlo simulation has been achieved.

  20. A comparison of dose savings of lead and lightweight aprons for shielding of 99m-Technetium radiation.

    Science.gov (United States)

    Warren-Forward, Helen; Cardew, Paul; Smith, Bradley; Clack, Llewellyn; McWhirter, Kym; Johnson, Stacey; Wessel, Kimberly

    2007-01-01

    Nuclear medicine technologists (NMTs) have the highest effective doses of radiation among medical workers. With increase in the use of lightweight materials in diagnostic radiography, the aim was to compare the effectiveness of lead and lightweight aprons in shielding from 99m-Technetium ((99m)Tc) gamma rays. The doses received from a scattering phantom to the entrance, 9cm depth and exit of a phantom were measured with LiF:Mg, Cu, P thermoluminescent dosemeters (TLDs). Doses and spectra were assessed without no shielding, with 0.5-mm lead and lightweight aprons. The lead and lightweight aprons decreased entrance surface doses by 76 and 59%, respectively. The spectral analysis showed that the lightweight apron provided better dose reduction at energies lead was 35% more efficient at higher energies. While lead apron demonstrated better shielding, the additional savings should be considered with the weight differential. It is concluded that the lightweight apron is suitable to be worn by NMTs interacting with patients injected with a (99m)Tc labelled radiopharmaceutical.

  1. Influence of lead apron shielding on absorbed doses from cone-beam computed tomography.

    Science.gov (United States)

    Rottke, Dennis; Andersson, Jonas; Ejima, Ken-Ichiro; Sawada, Kunihiko; Schulze, Dirk

    2017-06-01

    The aim of the present work was to investigate absorbed and to calculate effective doses (EDs) in cone-beam computed tomography (CBCT). The study was conducted using examination protocols with and without lead apron shielding. A full-body male RANDO® phantom was loaded with 110 GR200A thermoluminescence dosemeter chips at 55 different sites and set up in two different CBCT systems (CS 9500®, ProMax® 3D). Two different protocols were performed: the phantom was set up (1) with and (2) without a lead apron. No statistically significant differences in organ and absorbed doses from regions outside the primary beam could be found when comparing results from exposures with and without lead apron shielding. Consequently, calculating the ED showed no significant differences between the examination protocols with and without lead apron shielding. For the ProMax® 3D with shielding, the ED was 149 µSv, and for the examination protocol without shielding 148 µSv (SD = 0.31 µSv). For the CS 9500®, the ED was 88 and 86 µSv (SD = 0.95 µSv), respectively, with and without lead apron shielding. The results revealed no statistically significant differences in the absorbed doses between examination with and without lead apron shielding, especially in organs outside the primary beam. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Evaluation of a new pencil-type ionization chamber for dosimetry in computerized tomography beams; Avaliacao de uma nova camara de ionizacao tipo lapis para dosimetria em feixes de tomografia computadorizada

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Maysa C. de; Neves, Lucio P.; Silva, Natalia F. da; Santos, William de S.; Caldas, Linda V.E., E-mail: maysadecastro@gmail.com, E-mail: lpneves@ipen.br, E-mail: na.fiorini@gmail.com, E-mail: wssantos@ipen.br, E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-07-01

    For performing dosimetry in computed tomography beams (CT), use is made of a pencil-type ionization chamber, since this has a uniform response to this type of beam. The common commercial chambers in Brazil have a sensitive volume length of 10 cm. Several studies of prototypes of this type of ionization chamber have been conducted, using different materials and geometric configurations, in the Calibration Laboratory Instruments of the Institute of Nuclear and Energy Research (LCI) and these showed results within internationally acceptable limits. These ion chambers of 10 cm are widely used nowadays, however studies have revealed that they have underestimated the dose values. In order to solve this problem, we developed a chamber with sensitive volume length of 30 cm. As these are not yet very common and no study has yet been performed on LCI conditions on their behavior, is important that the characteristics of these dosemeters are known, and the influence of its various components. For your review, we will use the Monte Carlo code Penelope, freely distributed by the IAEA. This method has revealed results consistent with other codes. The results for this new prototype can be used in dosimetry of the CT of the hospitals and calibration laboratories as the LCI.

  3. Semiconductor scintillator detector for gamma radiation; Detector cintilador semicondutor para radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Laan, F.T.V. der; Borges, V.; Zabadal, J.R.S., E-mail: ftvdl@ufrgs.br, E-mail: borges@ufrgs.br, E-mail: jorge.zabadal@ufrgs.br [Universidade Federal do Rio Grande do Sul (GENUC/DEMEC/UFRGS), Porto Alegre, RS (Brazil). Grupo de Estudos Nucleares. Departamento de Engenharia Mecanica

    2015-07-01

    Nowadays the devices employed to evaluate individual radiation exposition are based on dosimetric films and thermoluminescent crystals, whose measurements must be processed in specific transductors. Hence, these devices carry out indirect measurements. Although a new generation of detectors based on semiconductors which are employed in EPD's (Electronic Personal Dosemeters) being yet available, it high producing costs and large dimensions prevents the application in personal dosimetry. Recent research works reports the development of new detection devices based on photovoltaic PIN diodes, which were successfully employed for detecting and monitoring exposition to X rays. In this work, we step forward by coupling a 2mm anthracene scintillator NE1, which converts the high energy radiation in visible light, generating a Strong signal which allows dispensing the use of photomultipliers. A low gain high performance amplifier and a digital acquisition device are employed to measure instantaneous and cumulative doses for energies ranging from X rays to Gamma radiation up to 2 MeV. One of the most important features of the PIN diode relies in the fact that it can be employed as a detector for ionization radiation, since it requires a small energy amount for releasing electrons. Since the photodiode does not amplify the corresponding photon current, it must be coupled to a low gain amplifier. Therefore, the new sensor works as a scintillator coupled with a photodiode PIN. Preliminary experiments are being performed with this sensor, showing good results for a wide range of energy spectrum. (author)

  4. Intercomparison of radiation protection instrumentation in a pulsed neutron field

    CERN Document Server

    Caresana, M; Esposito, A; Ferrarini, M; Golnik, N; Hohmann, E; Leuschner, A; Luszik-Bhadra, M; Manessi, G; Mayer, S; Ott, K; Röhrich, J; Silari, M; Trompier, F; Volnhals, M; Wielunski, M

    2014-01-01

    In the framework of the EURADOS working group 11, an intercomparison of active neutron survey meters was performed in a pulsed neutron field (PNF). The aim of the exercise was to evaluate the performances of various neutron instruments, including commercially available rem-counters, personal dosemeters and instrument prototypes. The measurements took place at the cyclotron of the Helmholtz-Zentrum Berlin für Materialien und Energie GmbH. The cyclotron is routinely used for proton therapy of ocular tumours, but an experimental area is also available. For the therapy the machine accelerates protons to 68 MeV. The interaction of the proton beam with a thick tungsten target produces a neutron field with energy up to about 60 MeV. One interesting feature of the cyclotron is that the beam can be delivered in bursts, with the possibility to modify in a simple and flexible way the burst length and the ion current. Through this possibility one can obtain radiation bursts of variable duration and intensity. All instru...

  5. Tests of shielding effectiveness of Kevlar and Nextel onboard the International Space Station and the Foton-M3 capsule.

    Science.gov (United States)

    Pugliese, M; Bengin, V; Casolino, M; Roca, V; Zanini, A; Durante, M

    2010-08-01

    Radiation assessment and protection in space is the first step in planning future missions to the Moon and Mars, where mission and number of space travelers will increase and the protection of the geomagnetic shielding against the cosmic radiation will be absent. In this framework, the shielding effectiveness of two flexible materials, Kevlar and Nextel, were tested, which are largely used in the construction of spacecrafts. Accelerator-based tests clearly demonstrated that Kevlar is an excellent shield for heavy ions, close to polyethylene, whereas Nextel shows poor shielding characteristics. Measurements on flight performed onboard of the International Space Station and of the Foton-M3 capsule have been carried out with special attention to the neutron component; shielded and unshielded detectors (thermoluminescence dosemeters, bubble detectors) were exposed to a real radiation environment to test the shielding properties of the materials under study. The results indicate no significant effects of shielding, suggesting that thin shields in low-Earth Orbit have little effect on absorbed dose.

  6. Eye lens surveillance. What is the reaction of international organizations?; Ueberwachung der Augenlinse. Wie reagieren die internationalen Organisationen?

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, R. [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany)

    2013-07-01

    The ICRP has lowered its recommendation for the limit of the dose to the lens of the eye for occupationally exposed persons down to 20 mSv per year on average (mean value of 5 years with 50 mSv per year at maximum); both the European Commission and the IAEA have adopted this reduction in their respective basic safety standards. Even before this (and still more since then) several international activities were started (among others): The ICRP adopted a stylised model of the eye lens for the calculation of dose conversion coefficients for their report ICRP 116. The European Commission funded the ORAMED project dealing with radiation protection in medicine. The IEC fixed requirements for Hp(3) eye dosemeters in their standard IEC 62387 on passive dosimetry systems. The ISO and the IAEA give a variety of practical advice in the standard ISO 15382 and in a technical document TecDoc (both still drafts) for both radiation protection as well as dosimetry. The ICRU recommends both phantoms, the slab and the cylinder, for most cases. In short: Most national procedures can orientate themselves by referring to international ones; however, some questions remain open. (orig.)

  7. TL and LOE dosimetric evaluation of diamond films exposed to beta and ultraviolet radiation; Evaluacion dosimetrica TL y LOE de peliculas de diamante expuestas a radiacion beta y ultravioleta

    Energy Technology Data Exchange (ETDEWEB)

    Preciado F, S.; Melendrez, R.; Chernov, V.; Barboza F, M. [Universidad de Sonora, A.P. 13 y A.P. 5-088, 83000 Hermosillo, Sonora (Mexico); Schreck, M. [Universitaet Augsburg, Institut fuer Physik D-86135 (Germany); Cruz Z, E. [ICN, UNAM, 04500 Mexico D.F. (Mexico)

    2005-07-01

    The diamond possesses a privileged position regarding other materials of great technological importance. Their applications go from the optics, microelectronics, metals industry, medicine and of course as dosemeter, in the registration and detection of ionizing and non ionizing radiation. In this work the results of TL/LOE obtained in two samples of diamond of 10 {mu}m thickness grown by the chemical vapor deposition method (CVD) assisted by microwave plasma. The films were deposited in a silicon substrate (001) starting from a mixture of gases composed of CH{sub 4}/H{sub 2} and 750 ppm of molecular nitrogen as dopant. The samples were exposed to beta radiation (Sr{sup 90}/ Y{sup 90}) and ultraviolet, being stimulated later on thermal (TL) and optically (LOE) to evaluate their dosimetric properties. The sample without doping presented high response TL/LOE to the ultraviolet and beta radiation. The TL glow curve of the sample without doping showed two TL peaks with second order kinetics in the range of 520 to 550 K, besides a peak with first order kinetics of more intensity around 607 K. The TL efficiency of the non doped sample is bigger than the doped with nitrogen; however the LOE efficiency is similar in both samples. The results indicate that the CVD diamond possesses excellent perspectives for dosimetric applications, with special importance in radiotherapy due to it is biologically compatible with the human tissue. (Author)

  8. Thermoluminescent dosimetry of beta radiations of {sup 90} Sr/ {sup 90} Y using ZrO{sub 2}: Eu; Dosimetria termoluminiscente de radiaciones beta de {sup 90} Sr/ {sup 90} Y usando ZrO{sub 2}: Eu

    Energy Technology Data Exchange (ETDEWEB)

    Olvera T, L.; Azorin N, J.; Barrera S, M.; Soto E, A.M. [UAM-I, 09340 Mexico D.F. (Mexico); Rivera M, T. [CICATA-IPN, Legaria 694, 11500 Mexico D.F. (Mexico)

    2005-07-01

    In this work the results of studying the thermoluminescent properties (TL) of the doped zirconium oxide with europium (ZrO{sub 2}: Eu{sup 3+}) before beta radiations of {sup 90}Sr/ {sup 90}Y are presented. The powders of ZrO{sub 2}: Eu{sup 3+} were obtained by means of the sol-gel technique and they were characterized by means of thermal analysis and by X-ray diffraction. The powders of ZrO{sub 2}: Eu{sup 3+}, previously irradiated with beta particles of {sup 90}Sr/ {sup 90}Y, presented a thermoluminescent curve with two peaks at 204 and 292 C respectively. The TL response of the ZrO{sub 2}: Eu{sup 3+} as function of the absorbed dose was lineal from 2 Gy up to 90 Gy. The fading of the information of the ZrO{sub 2}: Eu{sup 3+} was of 10% the first 2 hours remaining almost constant the information by the following 30 days. The ZrO{sub 2} doped with the (Eu{sup 3+}) ion it was found more sensitive to the beta radiation that the one of zirconium oxide without doping (ZrO{sub 2}) obtained by the same method. Those studied characteristics allow to propose to the doped zirconium oxide with europium like thermoluminescent dosemeter for the detection of the beta radiation. (Author)

  9. Determination of the tube voltage from clinic mammographic system using two types of detectors

    Energy Technology Data Exchange (ETDEWEB)

    Barreira, Jacqueline S.; Vivolo, Vitor, E-mail: jacsales@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-07-01

    The use of X rays for diagnostic radiology is very common and important to Medicine, including mammographic diagnosis focusing decreasing of the doses applied to the patients and preserving high quality of the diagnostic image. A quality control program of the irradiation systems it is necessary to control periodically the performance of the X-ray systems applied in that diagnosis in order to obtain the best results in that diagnosis. The verification of the beam characteristics is made by using standard dosimetric procedures which include the determination of the kilovoltage and the kerma rates for the different radiation qualities applied in the diagnosis. The Instruments Calibration Laboratory (LCI) of IPEN perform calibration in dosemeters used in radiation dosimetry (in diagnostic radiology) for many years and are improving their methodology to attend the actual demand of that equipment used in quality control of that X-radiation systems. The objective of that paper were the measurements of kVp and air kerma produced for one mammographic system of LCI, Model VMI - Graphmammo AF (Philips) using two different measurements systems from PTW (Diavolt) and Radcal (kVp meter) that procedure is just to determine the stability of that system that is used to perform diagnosis in mammography level. The results obtained with the two systems utilized shows good agreement. That measurement can be applied at a routine quality control program of that X-ray system. (author)

  10. Measurement of air kerma rates for 6- to 7-MeV high-energy gamma-ray field by ionisation chamber and build-up plate.

    Science.gov (United States)

    Kowatari, Munehiko; Tanimura, Yoshihiko; Tsutsumi, Masahiro

    2014-12-01

    The 6- to 7-MeV high-energy gamma-ray calibration field by the (19)F(p, αγ)(16)O reaction is to be served at the Japan Atomic Energy Agency. For the determination of air kerma rates using an ionisation chamber in the 6- to 7-MeV high-energy gamma-ray field, the establishment of the charged particle equilibrium must be achieved during measurement. In addition to measurement of air kerma rates by the ionisation chamber with a thick build-up cap, measurement using the ionisation chamber and a build-up plate (BUP) was attempted, in order to directly determine air kerma rates under the condition of regular calibration for ordinary survey meters and personal dosemeters. Before measurements, Monte Carlo calculations were made to find the optimum arrangement of BUP in front of the ionisation chamber so that the charged particle equilibrium could be well established. Measured results imply that air kerma rates for the 6- to 7-MeV high-energy gamma-ray field could be directly determined under the appropriate condition using an ionisation chamber coupled with build-up materials. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. AN EVALUATION OF THE BASIC CHARACTERISTICS OF A PLASTIC SCINTILLATING FIBRE DETECTOR IN CT RADIATION FIELDS.

    Science.gov (United States)

    Terasaki, Kento; Fujibuchi, Toshioh; Toyoda, Takatoshi; Yoshida, Yutaka; Akasaka, Tsutomu; Nohtomi, Akihiro; Morishita, Junji

    2016-12-01

    The ionisation chamber for computed tomography (CT) is an instrument that is most commonly used to measure the computed tomography dose index. However, it has been reported that the 10 cm effective detection length of the ionisation chamber is insufficient due to the extent of the dose distribution outside the chamber. The purpose of this study was to estimate the basic characteristics of a plastic scintillating fibre (PSF) detector with a long detection length of 50 cm in CT radiation fields. The authors investigated position dependence using diagnostic X-ray equipment and dependencies for energy, dose rate and slice thickness using an X-ray CT system. The PSF detector outputs piled up at a count rate of 10 000 counts ms(-1) in dose rate dependence study. With calibration, this detector may be useful as a CT dosemeter with a long detection length except for the measurement at high dose rate. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Thermoluminescence, luminescence optically stimulated and creation of defects in alkaline halogenides contaminated with Europium; Termoluminiscencia, luminiscencia opticamente estimulada y creacion de defectos en halogenuros alcalinos contaminados con Europio

    Energy Technology Data Exchange (ETDEWEB)

    Barboza F, M. [Centro de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, 83190 Hermosillo, Sonora (Mexico)

    1999-07-01

    The alkaline halogenides have been subject matter of investigations related with the search of sensor materials for X-ray bidimensional images or optical memories. The understanding of the damage formation processes generated by ionizing and non-ionizing radiations is important for the correct design of devices that working as detectors and dosemeters of both type of radiations. In this work we present the investigation results related with the defects produced by the ionizing radiation type X and ultraviolet light in the range of 200-360 nm in crystals of KCl: Eu{sup 2+} and KBr:Eu{sup 2+}. It is examined the thermoluminescence and luminescence spectra with the purpose of identifying the exciton processes, owing to the excitation of the halogenide ions in which the primary defects correspond to the F and H centers. It has been found that the 400-600 nm emission is associated with the luminescence type that in his turn can be associated with autotrapped excitons perturbed by the impurity. On the other hand, it is examined the emission spectra of the luminescence optically stimulated in crystals of KBr: Eu{sup 2+} and KCl: Eu{sup 2+} finding too that such materials would be used as optical memories susceptible of to store information, and through of photostimulation to read this. It was determined that the F centers participate in the luminescence optically stimulated in these crystals, as well as too in the recombination processes responsible by the thermoluminescent emission. (Author)

  13. Dating of the archaeological site 'El Tigre' by the thermoluminescent method; Fechamiento del sitio arqueologico 'El Tigre' por el metodo de termoluminiscencia

    Energy Technology Data Exchange (ETDEWEB)

    Portilla, R. De la [ENAH, Periferico Sur y Zapote, 14030 Mexico D.F. (Mexico); Gonzalez, P.R.; Mendoza, D. [ININ, 52750 La Marquesa, Ocoyoacac, Estado de Mexico (Mexico); Vargas, E. [Instituto de Investigaciones Antropologicas, UNAM, 04510 Mexico D.F. (Mexico); Ramirez, A. [Instituto de Geofisica, UNAM, 04510 Mexico D.F. (Mexico)

    2007-07-01

    Full text: The dating of pre hispanic pottery, is supported by techniques such as stratigraphy, typology, in physical and chemical procedures, as the analysis of {sup 14}C and the thermoluminescence (TL). The last one permits us obtain absolute dating of archaeological pottery with an acceptable precision. In this work we apply the applied the thermoluminescent technique to verify the age of the Pre-Classic and Classic Terminal periods proposed for the archaeological site 'El Tigre', Campeche. The samples were obtained during a work period and the radiation of the ground of background (emitted by the ground), as well as the contribution of the cosmic radiation was measured with thermoluminescent dosemeters of LiF: Mg,Cu,P + PTFE, put in the sample zone. The preliminary results indicate that not all the analyzed samples can be dated. The viability of the dating of the samples is discussed based on the fact and function of the presence of certain crystalline phases such as calcite and quartz. The discussion is complemented emphsizing the importance of handling the conditions of handling of samples. (Author)

  14. Bubble-detector measurements in the Russian segment of the International Space Station during 2009-12.

    Science.gov (United States)

    Smith, M B; Khulapko, S; Andrews, H R; Arkhangelsky, V; Ing, H; Lewis, B J; Machrafi, R; Nikolaev, I; Shurshakov, V

    2015-01-01

    Measurements using bubble detectors have been performed in order to characterise the neutron dose and energy spectrum in the Russian segment of the International Space Station (ISS). Experiments using bubble dosemeters and a bubble-detector spectrometer, a set of six detectors with different energy thresholds that is used to determine the neutron spectrum, were performed during the ISS-22 (2009) to ISS-33 (2012) missions. The spectrometric measurements are in good agreement with earlier data, exhibiting expected features of the neutron energy spectrum in space. Experiments using a hydrogenous radiation shield show that the neutron dose can be reduced by shielding, with a reduction similar to that determined in earlier measurements using bubble detectors. The bubble-detector data are compared with measurements performed on the ISS using other instruments and are correlated with potential influencing factors such as the ISS altitude and the solar activity. Surprisingly, these influences do not seem to have a strong effect on the neutron dose or energy spectrum inside the ISS. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Response of radiochromic dye films to low energy heavy charged particles

    CERN Document Server

    Buenfil, A E; Gamboa-Debuen, I; Aviles, P; Avila, O; Olvera, C; Robledo, R; Rodriguez-Ponce, M; Mercado-Uribe, H; Rodriguez-Villafuerte, M; Brandan, M E

    2002-01-01

    We have studied the possible use of radiochromic dye films (RCF) as heavy charged particle dosemeters. We present the results of irradiating two commercial RCF (GafChromic HD-810 and MD-55-1) with 1.5, 2.9 and 4.4 MeV protons, 1.4, 2.8, 4.7, 5.9, 6.8 MeV sup 4 He ions and 8.5 and 12.4 MeV sup 1 sup 2 C ions, at proton doses from about 1 Gy up to 3 kGy, helium ions doses from 3 Gy to 5 kGy and carbon ion doses from 30 Gy to 20 kGy. The films were scanned and digitized using commercial equipment. For a given particle, the response per unit dose at different energies indicates an energy dependence of the sensitivity, which is discussed. Comparison was made for the use of a standard spectrophotometer to obtain optical density readings versus a white light scanner.

  16. Implementation of an occupational monitoring program in diagnostic radiology at the 'Hospital Universitario Clementino Fraga Filho'; Elaboracao de um programa de monitoracao ocupacional em radiologia para o Hospital Universitario Clementino Fraga Filho

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Sergio Ricardo de; Carvalho, Antonio Carlos Pires [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia; Azevedo, Ana Cecilia Pedrosa de [Fundacao Instituto Oswaldo Cruz (Fiocruz), Rio de Janeiro, RJ (Brazil). Escola Nacional de Saude Publica]. E-mail: acpa@ensp.fiocruz.br

    2003-02-01

    An occupational monitoring program in diagnostic radiology was implemented at the Hospital Clementino Fraga Filho of the Rio de Janeiro Federal University (UFRJ), Brazil, in accordance with the Brazilian legislation. Previously, a survey of all personnel involved with ionizing radiation was performed. Many problems were observed: the great majority of the workers were not properly monitored; only three departments of the hospital kept an independent survey of the occupational doses; there was not a follow-up control of the high doses. With the implementation of the program, a new laboratory was chosen to read the dosemeters and this initiative resulted in reduction of the hospital costs. The inclusion of seven more departments in the program represented an increase of 60% in the number of monitored workers. The program also provided a system to control the high doses, especially in the Hemodynamics department, which presented the highest mean dose value (0.32 mSv/month). An area survey program was performed during different periods in places considered of high risk for the workers and for the public as well. At the same time, a software was used to build a database with the aim of controlling all personnel data. The implementation of the program provided all personnel involved a better knowledge of the risks associated with ionizing radiation and of radioprotection, and also awareness of the need of correct use of the personal dose monitors. (author)

  17. Absorbed and effective dose from periapical radiography by portable intraoral x-ray machine

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jeong Yeon; Han, Won Jeong; Kim, Eun Kyung [Dankook Univ. School of Dentistry, Seoul (Korea, Republic of)

    2007-09-15

    The purpose of this study was to measure the absorbed dose and to calculate the effective dose for periapical radiography done by portable intraoral x-ray machines. 14 full mouth, upper posterior and lower posterior periapical radiographs were taken by wall-type 1 and portable type 3 intraoral x-ray machines. Thermoluminescent dosemeters were placed at 23 sites at the layers of the tissue-equivalent ART woman phantom for dosimetry. Average tissue absorbed dose and radiation weighted dose were calculated for each major anatomical site. Effective dose was calculated using 2005 ICRP tissue weighted factors. On 14 full mouth periapical radiographs, the effective dose for wall-type x-ray machine was 30 Sv; for portable x-ray machines were 30 Sv, 22 Sv, 36 Sv. On upper posterior radiograph, the effective dose for wall-type x-ray machine was 4 Sv; for portable x-ray machines doses were 4 Sv, 3 Sv, 5 Sv. On lower posterior radiograph, the effective dose for wall type x-ray machine was 5 Sv; for portable x-ray machines doses were 4 Sv, 4 Sv, 5 Sv. Effective doses for periapical radiographs performed by portable intraoral x-ray machines were similar to doses for periapical radiographs taken by wall type intraoral x-ray machines.

  18. Intercomparison of radiation protection devices in a high-energy stray neutron field. Part II: Bonner sphere spectrometry

    CERN Document Server

    Wiegel, B; Bedogni, R; Caresana, M; Esposito, A; Fehrenbacher, G; Ferrarini, M; Hohmann, E; Hranitzky, C; Kasper, A; Khurana, S; Mares, V; Reginatto, M; Rollet, S; Rühm, W; Schardt, D; Silari, M; Simmer, G; Weitzenegger, E

    2009-01-01

    The European Commission has funded within its 6th Framework Programme a three-year project (2005–2007) called CONRAD, COordinated Network for RAdiation Dosimetry. A major task of the CONRAD Work Package “complex mixed radiation fields at workplaces” was to organise a benchmark exercise in a workplace field at a high-energy particle accelerator where neutrons are the dominant radiation component. The CONRAD benchmark exercise took place at the Gesellschaft für Schwerionenforschung mbH (GSI) in Darmstadt, Germany in July 2006. In this paper, the results of the spectrometry using four extended -range Bonner sphere spectrometers of four different institutes are reported. Outside Cave A the neutron spectra were measured with three spectrometers at six selected positions and ambient dose equivalent values were derived for use in the intercomparison with other area monitors and dosemeters. At a common position all three spectrometers were used to allow a direct comparison of their results which acts as an int...

  19. The effective dose of different scanning protocols using the Sirona GALILEOS(®) comfort CBCT scanner.

    Science.gov (United States)

    Chambers, D; Bohay, R; Kaci, L; Barnett, R; Battista, J

    2015-01-01

    To determine the effective dose and CT dose index (CTDI) for a range of imaging protocols using the Sirona GALILEOS(®) Comfort CBCT scanner (Sirona Dental Systems GmbH, Bensheim, Germany). Calibrated optically stimulated luminescence dosemeters were placed at 26 sites in the head and neck of a modified RANDO(®) phantom (The Phantom Laboratory, Greenwich, NY). Effective dose was calculated for 12 different scanning protocols. CTDI measurements were also performed to determine the dose-length product (DLP) and the ratio of effective dose to DLP for each scanning protocol. The effective dose for a full maxillomandibular scan at 42 mAs was 102 ± 1 μSv and remained unchanged with varying contrast and resolution settings. This compares with 71 μSv for a maxillary scan and 76 μSv for a mandibular scan with identical milliampere-seconds (mAs) at high contrast and resolution settings. Changes to mAs and beam collimation have a significant influence on effective dose. Effective dose and DLP vary linearly with mAs. A collimated maxillary or mandibular scan decreases effective dose by approximately 29% and 24%, respectively, as compared with a full maxillomandibular scan. Changes to contrast and resolution settings have little influence on effective dose. This study provides data for setting individualized patient exposure protocols to minimize patient dose from ionizing radiation used for diagnostic or treatment planning tasks in dentistry.

  20. Studies and development of essential systems in the surveillance program, life extension potential of the vessel and master curve in nuclear power plants; Estudios y desarrollo de sistemas necesarios en el programa de vigilancia, potencial extension de vida de la vasija y curva maestra en nucleoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Romero C, J.; Hernandez C, R.; Rocamontes A, M.; Perez R, N., E-mail: jesus.romero@inin.gob.m [ININ, Departamento de Automatizacion e Instrumentacion, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-07-01

    The nuclear power plants owners should demonstrate that the effects of the embrittlement by neutronic radiation do not commit the structural integrity of the pressure vessel of the nuclear reactors, so much under conditions of routine operation as below an accident postulate. In consequence, in Mexico surveillance programs of the vessels of the nuclear power plant of Laguna Verde exist, in which three surveillance capsules are have by reactor. A surveillance capsule is composed by a support and between six and eight containers for test tubes and dosemeters. The containers for test tubes are of two types: rectangular container for Charpy V test tubes and cylindrical container for tension test tubes. These test tubes are subject to a same or bigger neutronic flow that of the vessel, being representative witness of the mechanical conditions of the vessel. The objective of to assay the test tubes to impact is to evaluate the embrittlement grade of the vessel beforehand during its useful life of operation, as well as to determinate the running of the ductile-fragile transition temperature in function of the time. (Author)

  1. Measurement of dose to skin using TLD of several radiodiagnostic studies in San Jose, Costa Rica; Medicion de dosis a piel utilizando TLD de varios estudios radiodiagnosticos en San Jose, Costa Rica

    Energy Technology Data Exchange (ETDEWEB)

    Mora, P. [Laboratorio de Fisica Nuclear Aplicada, Escuela de Fisica, Universidad de Costa Rica, San Jose (Costa Rica)

    1998-12-31

    It is quantified the radiation doses on skin for several radiodiagnostic studies in patients of the Calderon Guardia Hospital in San Jose, Costa Rica at the period October 1997-September 1998 using thermoluminescent dosemeters TLD 100. The crystals receive the decoction standard procedures and they are arranged at the middle of the irradiation field. For a total of 973 radiodiagnostic studies it was found that the dose on skin in mGy are: 2.09 for thorax AP/AP, 5.33 for thorax LAT, 5.35 for skull AP/PA, 2.98 for skull LAT, 10.74 for abdomen, hips and pelvis, 6.20 for spines AP, 9.35 for spines LAT, 11.48 for lumbar columns AP, 29.99 for lumbar columns LAT and 6.87 for intravenous skin diagrams (first plate ap). It is produced thus the first reference bank for the national hospitals, which is compared with the orientation levels of doses for IAEA. Recommendations to diminish the collective doses through quality control programs are discussed, taking as goal to have got radiographs of excellent diagnostic quality, but with the less possible doses. (Author)

  2. Radioactivity concentrations and dose assessment for soil samples around nuclear power plant IV in Taiwan.

    Science.gov (United States)

    Tsai, Tsuey-Lin; Lin, Chun-Chih; Wang, Tzu-Wen; Chu, Tieh-Chi

    2008-09-01

    Activity concentrations and distributions of natural and man-made radionuclides in soil samples collected around nuclear power plant IV, Taiwan, were investigated for five years to assess the environmental radioactivity and characterisation of radiological hazard prior to commercial operation. The activity concentrations of radionuclides were determined via gamma-ray spectrometry using an HPGe detector. Data obtained show that the average concentrations of the (238)U and (232)Th series, and (40)K, were within world median ranges in the UNSCEAR report. The (137)Cs ranged from 2.46 +/- 0.55 to 12.13 +/- 1.31 Bq kg(-1). The terrestrial absorbed dose rate estimated by soil activity and directly measured with a thermoluminescence dosemeter (excluding cosmic rays), and the annual effective doses, were 45.63, 57.34 nGy h(-1) and 57.19 microSv, respectively. Experimental results were compared with international recommended values. Since the soil in this area is an important building material, the mean radium equivalent activity, external and inhalation hazard indices and the representative level index using various models given in the literature for the study area were 98.18 Bq kg(-1), 0.27, 0.34 and 0.73, respectively, which were below the recommended limits. Analytical results demonstrate that no radiological anomaly exists. The baseline data will prove useful and important in estimating the collective dose near the new nuclear power plant under construction in Taiwan.

  3. Geant4 simulation of the CERN-EU high-energy reference field (CERF) facility.

    Science.gov (United States)

    Prokopovich, D A; Reinhard, M I; Cornelius, I M; Rosenfeld, A B

    2010-09-01

    The CERN-EU high-energy reference field facility is used for testing and calibrating both active and passive radiation dosemeters for radiation protection applications in space and aviation. Through a combination of a primary particle beam, target and a suitable designed shielding configuration, the facility is able to reproduce the neutron component of the high altitude radiation field relevant to the jet aviation industry. Simulations of the facility using the GEANT4 (GEometry ANd Tracking) toolkit provide an improved understanding of the neutron particle fluence as well as the particle fluence of other radiation components present. The secondary particle fluence as a function of the primary particle fluence incident on the target and the associated dose equivalent rates were determined at the 20 designated irradiation positions available at the facility. Comparisons of the simulated results with previously published simulations obtained using the FLUKA Monte Carlo code, as well as with experimental results of the neutron fluence obtained with a Bonner sphere spectrometer, are made.

  4. Extremity dosimetry with triple-TLD - analysis of the results and experiences in personal monitoring; Teilkoerperdosimetrie mit Dreifach-TLD - Analyse der Ergebnisse und Erfahrungen in der Strahlenschutzueberwachung

    Energy Technology Data Exchange (ETDEWEB)

    Heinzelmann, M. [Forschungszentrum Juelich GmbH (Germany). Abt. Sicherheit und Strahlenschutz; Hill, P. [Forschungszentrum Juelich GmbH (Germany). Abt. Sicherheit und Strahlenschutz; Pillath, J. [Forschungszentrum Juelich GmbH (Germany). Abt. Sicherheit und Strahlenschutz

    1994-12-31

    During the last decade personal monitoring with triple TLD proofed to be very helpful in assessing extremity doses obtained by radiation workers in mixed radiation fields at the Research Centre Juelich GmbH. Doses observed are generally very low. Only 30% of the results exceeded 1 mSv. A fraction of 80% shows essential contributions from {beta}-radiation. Analysis of TLD readings with respect to the {beta}-energies is described. In 5% of the cases low energy {beta}-radiation (E{sub {beta}max}<230 keV) is involved, which most types of extremity dosemeters commonly in use are insensitive to. Single cases are observed, where glowcurves are atypical for TLD-100 readings and suggest the presence of chemical agencies (Chemiluminescence). (orig.) [Deutsch] Im Forschungszentrum Juelich GmbH haben sich zur Teilkoerperdosisueberwachung in gemischten Strahlenfeldern Dreifach-TLD sehr geeignet gezeigt. Die Personendosen sind im allgemeinen gering. Sie sind nur zu 30%{>=}1 mSv. Davon sind in etwa 80% die Personendosen im wesentlichen durch {beta}-Strahlung bedingt, und bei 5% handelt es sich um niederenergetische {beta}-Strahluung (E{sub {beta}max}<230 keV), die von der Mehrzahl ueblicher Teilkoerperdosimeter nicht erfasst wird. Vereinzelt wird bei der Dosimeterauswertung eine ungewoehnliche Form der Glowkurve festgestellt, deren Ursache nicht bekannt ist. Ein Chemikalieneinfluss wird nicht ausgeschlossen. (orig.)

  5. Monitoring of radiation exposure. Annual report 2000; Saeteilyn kaeyttoe ja muu saeteilytoiminta. Vuosiraportti 2000

    Energy Technology Data Exchange (ETDEWEB)

    Rantanen, E. [ed.

    2001-03-01

    At the end of 2000, there were 1,779 valid safety licenses in Finland for the use of radiation. In addition, there were 2,038 responsible parties for dental x-ray diagnostics. The registry Radiation and Nuclear Safety Authority (STUK) listed 13,754 radiation sources and 270 radionuclide laboratories. In the year 2000 360 inspections were made concerning the safety licences and 53 concerning dental x-ray diagnostics. The import of radioactive substances amounted to 175,836 GBq and export to 74,420 GBq. Short-lived radionuclides produced in Finland amounted to 55,527 GBq. In the year 2000 there were 10,846 workers monitored for radiation exposure at 1,171 work sites. Of these employees, 27% received an annual dose exceeding the recording level. The annual effective dose limit was not exceeded. The total dose recorded in the dose registry(sum of the individual dosemeter readings) was 6.5 Sv in 2000.

  6. Thermoluminescence of X irradiated chlorapatite containing silver

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Y.; Mizuguchi, K.; Yokota, S.; Takeuchi, N.

    1987-01-01

    Thermoluminescence (TL) of sintered calcium chlorapatites doped with 0.03 wt% silver and appreciable amounts of sodium ions have been investigated, because the effective atomic number of calcium chlorapatite is close to that of human bones and teeth. The presence of silver ions increases the sensitivity of the TL peaks to radiation dose, but the peak temperatures are not affected by the activators. For the sake of comparison, CuCl/sub 2/ and NdCl/sub 3/ doped samples were made and their TL glow curves were measured. They showed the same peak temperatures at 65 and 170/sup 0/C as the silver doped sample, but the intensities were different. These results may indicate that the charge carriers should be holes which are trapped by matrices of the samples. Electrons are trapped by the metal activators, some of which are detected by ESR. The linear response of the TL peak at 170/sup 0/C relative to exposure was observed up to about 2.58 C.kg/sup -1/. About 85% of the original intensity after an irradiation of 2.58 x 10/sup -2/C.kg/sup -1/ was preserved for 30 days at room temperature in the dark. This material could therefore be used for a TL dosemeter.

  7. Thermoluminescent monitoring of the solar ultraviolet radiation with KCl: Eu{sup 2+} crystals; Monitoreo termoluminiscente de la radiacion solar ultravioleta con cristales de KCl: Eu{sup 2+}

    Energy Technology Data Exchange (ETDEWEB)

    Chernov, V.; Melendrez, R.; Barboza F, M. [Centro de Investigacion en Fisica, Universidad de Sonora, A.P. 5-88, Hermosillo, Sonora (Mexico)

    2000-07-01

    In this work it has been investigating the Tl properties of KCl: Eu{sup 2+} subjected to solar direct radiation. Also it was realized irradiation with the Deuterium and Xenon lamps. It was used a set of filters and a Katos monochromator 0.25 M to determine the spectral response to Tl peaks and a study of them with respect to the duration of the Sun irradiation. After of the Sun irradiation the Tl curves show several peaks between the ambient temperature and 673 K. The relation between peaks depends strongly of the irradiation time and the different solar light wavelength. It is possible to divide the Tl peaks in two groups. The first one (T<473 K) is very sensitive to ultraviolet radiation but it is strongly affected by visible light. The second one (T>473 K) is not too sensitive but is more stable under optical whitening. Here the obtained results are discussed with respect to UV dosemeters development for environment which facilitate to obtain direct measurements of the UV index. (Author)

  8. A simple and safe method for 131I radiolabeling of rituximab for myeloablative high-dose radioimmunotherapy.

    Science.gov (United States)

    Tran, Ly; Baars, Joke W; Maessen, Harry J; Hoefnagel, Cornelis A; Beijnen, Jos H; Huitema, Alwin D R

    2009-02-01

    The aim of this study was to develop a safe and simple radiolabeling and purification procedure for high-dose (131)I-rituximab for treatment of patients with non-Hodgkin's lymphoma. As the starting point, the conventional Iodogen-coated vial method was applied. After the iodogen-coated monoclonal antibody (mAb) method, a labeling method involving much lower amounts of iodogen was assessed. Subsequently, (131)I-rituximab was purified with a tangential flow filtration system. Quality control of the final product was performed by using size-exclusion chromatography with ultraviolet detection and by instant high-performance thin-layer chromatography. Immunoreactivity was determined by using a cell-binding assay. During the labeling procedure, radiation exposure was monitored. The coated vial method resulted in a low radiation exposure, but immunoreactivity was highly compromised (37%). Also, formation of aggregates was observed. The maximal observed effective dose was 18 microSv, finger thermoluminescence dosemeters revealed a hand-dose measurement of 0.8 mSv. The second method resulted in an immunoreactivity of 70%. Radiochemical purity was >97% after purification. The maximal measured effective dose was 31 microSv, and detected exposure to the hands was 1.9 mSv. We have developed a simple labeling technique for the preparation of high-dose (131)I-rituximab. The method offers a high purity and retained immunoreactivity with minimal radiation exposure for involved personnel.

  9. The PTB thermal neutron reference field at GeNF

    Energy Technology Data Exchange (ETDEWEB)

    Boettger, R.; Friedrich, H.; Janssen, H.

    2004-07-01

    The experimental setup and procedure for the characterization of the thermal neutron reference field established at the Geesthacht neutron facility (GeNF) of the GKSS is described. The neutron beam, free in air, with a maximum flux of 10{sup 6} s{sup -1}, can easily be reduced to less than 10{sup 4} s{sup -1} by using a diaphragm variable in size and without changing the beam divergence. Also, the spectral distribution with a mean energy of 45 meV, measured by time-of-flight over a 6.6 m long flight path, is independent of the beam current chosen. In the 2002/2003 experiments reported here, a {sup 6}Li glass detector was employed to determine the absolute beam current and to calibrate the {sup 3}He transmission beam monitor. In addition, activation measurements of gold foils were carried out at a reduced beam divergence. The results agree within {+-}2%. Furthermore, the beam is characterized by a low gamma background intensity and a negligible fraction of epithermal neutrons. Irradiations in combination with a scanner device to achieve a homogeneously illuminated scan field have shown that the thermal beam is well suited for dosemeter development and for the calibration of radiation protection instruments. (orig.)

  10. The 2008 intercomparison exercise for radon gas measurement instruments at PSI; Die Vergleichsmessung 2008 fuer Radongasmessgeraete am PSI

    Energy Technology Data Exchange (ETDEWEB)

    Butterweck, G.; Schuler, Ch.; Mayer, S.

    2010-09-15

    Sixteen radon measurement services participated in the 2008 Radon Intercomparison Exercise performed at the Reference Laboratory for Radon Gas Activity Concentration Measurements at the Paul Scherrer Institute (PSI) during August 28{sup th} to September 7{sup th}, 2008 on behalf of the Swiss Federal Office of Public Health (FOPH). Twelve of these laboratories were approved by the FOPH and their participation in the intercomparison exercise was a requirement to warrant quality of measurement. Radon gas dosemeters (etched-track, electronic and electret ionisation chambers) and instruments (ionization chambers) were exposed in the PSI Radon Chamber in a reference atmosphere with an average radon gas concentration of 627 Bq m{sup -3} leading to a radon gas exposure of 155 kBq h m{sup -3}. One measuring instrument participating for testing purposes stored values for part of the exposure interval (30.8. - 7.9.2008). The exposure during this partial interval was 117 kBq h m{sup -3} at an average radon gas concentration of 624 Bq m{sup -3}. The exposure of 155 kBq h m{sup -3} was the lowest used at the PSI intercomparisons down to the present day. Especially the LLT electret ionisation chambers used by some of the laboratories reached the lower end of their measurement range with this exposure. Unexpected deviations of instruments of the same model seem to show a dependence on the serial number and thus production date. (authors)

  11. Doses to nurses by the technetium-99m, in private and public sector; Doses aux infirmieres donnees par le technetium-99m, dans le prive et le public

    Energy Technology Data Exchange (ETDEWEB)

    Bied, J.Ch.; Philippon, B. [Hospice Civils de Lyon, 69 (France)

    1999-07-01

    The global body dose due to the technetium is 1.2 and 1.9 mSv for the two nurses of the private sector. In the public sector, the level reached by the personnel is 0.75 mSv for the global body dose, and the only technetium (global body dose 1.4 and 2.1 mSv for the private sector, 0.95 for the public sector) and for the whole of radiations measured by the O.P.R.I. film dosemeter. The doses received at the fingers level present higher levels in the private sector. But these values, 15.2 and 10.7 mSv by month, that is to say 180 mSv by year are the 2/5 of the maximum permissible value. The two persons of the private sector received whole body doses, higher that the doses of the public sector. These doses are about 1.2 to 1.9 these ones received in the public sector. (N.C.)

  12. An image analyzer system for the analysis of nuclear traces; Un sistema analizador de imagenes para el analisis de trazas nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Cuapio O, A

    1990-10-15

    Inside the project of nuclear traces and its application techniques to be applied in the detection of nuclear reactions of low section (non detectable by conventional methods), in the study of accidental and personal neutron dosemeters, and other but, are developed. All these studies are based on the fact that the charged particles leave latent traces of dielectric that if its are engraved with appropriate chemical solutions its are revealed until becoming visible to the optical microscope. From the analysis of the different trace forms, it is possible to obtain information of the characteristic parameters of the incident particles (charge, mass and energy). Of the density of traces it is possible to obtain information of the flow of the incident radiation and consequently of the received dose. For carry out this analysis has been designed and coupled different systems, that it has allowed the solution of diverse outlined problems. Notwithstanding it has been detected that to make but versatile this activity is necessary to have an Image Analyzer System that allow us to digitize, to process and to display the images with more rapidity. The present document, presents the proposal to carry out the acquisition of the necessary components for to assembling an Image Analyzing System, like support to the mentioned project. (Author)

  13. Thermoluminescent dosimetry of beta radiations of {sup 90} Sr/ {sup 90} Y using amorphous ZrO{sub 2}; Dosimetria termoluminiscente de radiaciones beta de {sup 90} Sr/ {sup 90} Y usando ZrO{sub 2} amorfo

    Energy Technology Data Exchange (ETDEWEB)

    Rivera M, T. [CICATA-Legaria, IPN, Legaria Num. 694, 11500 Mexico D.F. (Mexico); Olvera T, L.; Azorin N, J.; Barrera R, M.; Soto E, A.M. [UAM-I, 09340 Mexico D.F. (Mexico)

    2005-07-01

    In this work the results of studying the thermoluminescent properties (Tl) of the zirconium oxide in its amorphous state (ZrO{sub 2}-a) before beta radiations of {sup 90} Sr/ {sup 90} Y are presented. The amorphous powders of the zirconium oxide were synthesized by means of the sol-gel technique. The sol-gel process using alkoxides like precursors, is an efficient method to prepare a matrix of zirconium oxide by hydrolysis - condensation of the precursor to form chains of Zr-H{sub 3} and Zr-O{sub 2}. One of the advantages of this technique is the obtention of gels at low temperatures with very high purity and homogeneity. The powders were characterized by means of thermal analysis and by X-ray diffraction. The powders of ZrO{sub 2}-a, previously irradiated with beta particles of {sup 90} Sr/{sup 90} Y, presented a thermoluminescent curve with two peaks at 150 and 257 C. The dissipation of the information of the one ZrO{sub 2}-a was of 40% the first 2 hours remaining constant the information for the following 30 days. The reproducibility of the information was of {+-} 2.5% in standard deviation. The studied characteristics allow to propose to the amorphous zirconium oxide as thermoluminescent dosemeter for the detection of beta radiation. (Author)

  14. Estimation of the risk of secondary cancer in the thyroid gland and the breast outside the treated volume in patients undergoing brain, mediastinum and breast radiotherapy.

    Science.gov (United States)

    Vlachopoulou, Vassiliki; Malatara, Georgia; Delis, Harry; Kardamakis, Dimitrios; Panayiotakis, George

    2013-04-01

    The purpose of this study was to measure the peripheral dose which is the absorbed dose in organs located outside the treatment volume such as the thyroid gland and the breast in patients undergoing radiotherapy, utilising the MOSFET dosemeters, as well as to estimate the probability of secondary cancer. The thyroid gland doses, expressed as a percentage of the prescribed dose (%TD), were measured to be 2.0±0.3 %, in whole brain irradiation, 10.0±8.0 % in mediastinum treatment and 8.0±2.0 and 2.0±0.8 % in breast treatment, with and without the supraclavicular irradiation, respectively, with a corresponding risk of 0.2, 2.0, 1.0 and 0.3 %. The dose to the breast was 7.0±2.0 %, in the mediastinum treatment, and 4.0±1.0 and 2.0±0.8 %, in the breast treatment, with and without supraclavicular irradiation, respectively, with a corresponding risk of 4.0, 2.0 and 1.0 %. Although the results indicate that the risk is not negligible, its significance should be considered in conjunction with the existing pathology and age of the patients.

  15. Seasonal variation of indoor radon-222 levels in dwellings in Ramallah province and East Jerusalem suburbs, Palestine.

    Science.gov (United States)

    Leghrouz, Amin A; Abu-Samreh, Mohammad M; Shehadeh, Ayah K

    2012-01-01

    This study presents the seasonal variations of indoor radon levels in dwellings located in the Ramallah province and East Jerusalem suburbs, Palestine. The measurements were performed during the summer and winter of the year 2006/2007 using CR-39 solid-state-nuclear-track detectors. The total number of investigated buildings is 75 in summer and 81 in winter. A total number of 142 dosemeters are installed in dwellings for each season for a period of almost 100 d. The radon concentration levels in summer varied from 43 to 192 Bq m(-3) for buildings in the Ramallah province and from 30 to 655 Bq m(-3) for East Jerusalem suburbs. In winter, the radon concentration levels are found to vary from 38 to 375 Bq m(-3) in the Ramallah buildings and from 35 to 984 Bq m(-3) in East Jerusalem suburbs. The obtained results for radon concentration levels in most places are found to be within the accepted international levels.

  16. Monte carlo study of MOSFET packaging, optimised for improved energy response: single MOSFET filtration.

    Science.gov (United States)

    Othman, M A R; Cutajar, D L; Hardcastle, N; Guatelli, S; Rosenfeld, A B

    2010-09-01

    Monte Carlo simulations of the energy response of a conventionally packaged single metal-oxide field effect transistors (MOSFET) detector were performed with the goal of improving MOSFET energy dependence for personal accident or military dosimetry. The MOSFET detector packaging was optimised. Two different 'drop-in' design packages for a single MOSFET detector were modelled and optimised using the GEANT4 Monte Carlo toolkit. Absorbed photon dose simulations of the MOSFET dosemeter placed in free-air response, corresponding to the absorbed doses at depths of 0.07 mm (D(w)(0.07)) and 10 mm (D(w)(10)) in a water equivalent phantom of size 30 x 30 x 30 cm(3) for photon energies of 0.015-2 MeV were performed. Energy dependence was reduced to within + or - 60 % for photon energies 0.06-2 MeV for both D(w)(0.07) and D(w)(10). Variations in the response for photon energies of 15-60 keV were 200 and 330 % for D(w)(0.07) and D(w)(10), respectively. The obtained energy dependence was reduced compared with that for conventionally packaged MOSFET detectors, which usually exhibit a 500-700 % over-response when used in free-air geometry.

  17. Retrospective dosimetry: Dose evaluation using unheated and heated quartz from a radioactive waste storage building

    DEFF Research Database (Denmark)

    Jain, M.; Bøtter-Jensen, L.; Murray, A.S.

    2002-01-01

    In the assessment of dose received from a nuclear accident, considerable attention has been paid to retrospective dosimetry using heated materials such as household ceramics and bricks. However, unheated materials such as mortar and concrete are more commonly found in industrial sites and particu......In the assessment of dose received from a nuclear accident, considerable attention has been paid to retrospective dosimetry using heated materials such as household ceramics and bricks. However, unheated materials such as mortar and concrete are more commonly found in industrial sites...... and particularly in nuclear installations. These materials contain natural dosemeters Such as quartz. which usually is less sensitive than its heated counterpart. The potential of quartz extracted from mortar in a wall of a low-level radioactive-waste storage facility containing distributed sources of Co-60 and Cs......-137 has been investigated. Dose-depth profiles based on small aliquots and single grains from the quartz extracted from the mortar samples are reported here. These are compared with results from heated quartz and polymineral fine grains extracted from an adjacent brick, and the integrated dose...

  18. Production of X-rays by inverse Compton effect; Produccion de rayos X por efecto Compton inverso

    Energy Technology Data Exchange (ETDEWEB)

    Mainardi, R.T. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina)

    2005-07-01

    X-rays and gamma rays of high energy values can be produced by the scattering of low energy photons with high energy electrons, being this a process controlled by the Compton scattering. If a laser beam is used, the x-ray beam inherits the properties of intensity, monochromaticity and collimation from the laser. In this work we analyze the generation of intense x-ray beams of energies between 10 and 100 KeV to be used in a wide range of applications where a high intensity and high degrees of monochromaticity and polarization are important properties to improve image reduce doses and improve radiation treatments. To this purpose we evaluated, using relativistic kinematics the scattered beam properties in terms of the scattering angle. This arrangement is being considered in several worldwide laboratories as an alternative to synchrotron radiation and is referred to as 'table top synchrotron radiation', since it cost of installation is orders of magnitude smaller than a 'synchrotron radiation source'. The radiation beam might exhibit non-linear properties in its interaction with matter, in a similar way as a laser beam and we will investigate how to calibrate and evaluate TLD dosemeters properties, both in low and high intensity fields either mono or polyenergetic in wide spectral energy ranges. (Author)

  19. Dosimetry through the Secondary Laboratory of Dosimetric Calibration of Mexico; Dosimetria a traves del Laboratorio Secundario de Calibracion Dosimetrica de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Tovar M, V.M.; Alvarez R, J.T.; Medina O, V.P.; Vergara M, F.; Anaya M, R.; Cejudo A, J.; Salinas L, B. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2004-07-01

    In the beginnings of the sixty years an urgent necessity is presented mainly in the developing countries, of improving in important form the accuracy in the dosimetry of external faces in therapy of radiations (radiotherapy centers), mainly in the calibration of ''clinical dosemeters''. In 1976 the International Atomic Energy Agency, (IAEA), and the World Health Organization, (WHO), they carried out a mutual agreement with regard to the establishment and operation of a net of Secondary Patron Laboratories of Dosimetry, (LSCD). The necessity to establish measure patterns in the field of the dosimetry of the ionizing radiations, is necessary, to have an accuracy but high in the dosimetry of the radiation beams in therapy which is highly dependent of the dose given to the tumor of those patient with cancer. Similar levels of accuracy are required in protection measures to the radiation with an acceptable smaller accuracy, however, when the personal dosemeters are used to determine the doses received by the individuals under work conditions, such mensurations in therapy of radiations and radiological protection will have traceability through a chain of comparisons to primary or national patterns. The traceability is necessary to assure the accuracy and acceptability of the dosimetric measures, as well as, the legal and economic implications. The traceability is also necessary in the dosimetry of high dose like in the sterilization of different products. The main function of the LSCD is to provide a service in metrology of ionizing radiations, maintaining the secondary or national patterns, which have a traceability to the International System of measures, which is based for if same in the comparison of patterns in the Primary Laboratories of Dosimetry (LPD) under the auspice of the International Office of Weights and Measure (BIPM). The secondary and national patterns in the LSCD constitute in Mexico, the national patterns of the magnitudes in the

  20. Environmental monitoring system with TLD; Sistema de monitoreo ambiental con TLD

    Energy Technology Data Exchange (ETDEWEB)

    Aguerre, L.; Carelli, J.; Gregori, B. [Autoridad Regulatoria Nuclear Argentina (Argentina)]. e-mail: laguerre@cae.arn.gov.ar

    2006-07-01

    Presently work the methodology used by the Laboratory of Thermoluminescent Dosimetry (TLD) of the Nuclear Regulatory Authority (RNA) to gauge it system of environmental monitoring in function of the media absorbed dose rate in free air and the environmental dose equivalent, H{sup *}(10), according to the recommendation ICRU Report 47 is described. It was studied the response of the environmental dosemeter (DA) in fields of photonic radiation of energies W60, Wl 10, W200 and {sup 137} Cs. The irradiations were carried out following the recommendations of the standard ISO:4037. It was analyzed the response in the DA of the detectors LiF: Mg, Ti and CaF{sub 2}: Dy for the different radiation qualities and the relative response at {sup 137} Cs of both. The methodology used in the evaluation of the dose includes: the correction of the readings of both detectors by fading, gotten experimentally, the witness of transfers, the energy answer and the value of the zero. The dose is calculated applying the average pondered in uncertainty of the dose obtained for each type of detector. Its were analyzed and calculated the uncertainties that affect to the measurement following the recommendation of the Argentine standard IRAM 35050. The detection limit of the absorbed dose rate in free air of this system it is 3.5 n Gy/h for a period of sampling of 3 months. With this detection limit environmental dose equivalent rates of the order of 70 n Sv/h are measured with an expanded uncertainty of the order of 10% with a cover factor k = 2. (Author)

  1. Development of a portable triple silicon detector telescope for beta spectroscopy and skin dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Helt-Hansen, J

    2000-11-01

    It is now recognized that beta radiation can be a significant radiation problem for exposure of the skin. There is thus a need for a portable and rugged active beta dosemeter-spectrometer to carry out immediate measurements of doses and energies of beta particles even in the presence of photon radiation. The main objective of this report is to describe the development of such an instrument. A beta-spectrometer has been developed consisting of three silicon surface barrier detectors with the thickness: 50{mu}m/150{mu}m/7000{mu}m covered by a 2 {mu}m thick titanium window. The spectrometer is capable of measuring electron energies from 50 keV to 3.5 MeV. The spectrometer is characterized by a compact low weight design, achieved by digital signal processing beginning at an early stage in the signal chain. 255 channels are available for each of the three detectors. The spectrometer is controlled by a laptop computer, which also handles all subsequent data analysis. By use of coincidence/anti-coincidence considerations of the absorbed energy in the three detector elements, counts caused by electrons are separated from those originating from photons. The electron energy distribution is multiplied by a set of conversion coefficients to obtain the dose at 0.07 mm tissue. Monte Carlo calculations has been used to derive the conversion coefficients and to investigate the influence of noise and the design of detector assembly on the performance of the spectrometer. This report describes the development of the spectrometer and its mode of operation, followed by a description of the Monte Carlo calculations carried out to obtain the conversion coefficients. Finally is the capability of the telescope spectrometer to measure beta and photon spectra as well as beta dose rates in pure beta and mixed beta/photon radiation fields described. (au)

  2. Intestinal biospy in children with coeliac disease; a Swedish national study of radiation dose and risk

    Energy Technology Data Exchange (ETDEWEB)

    Persliden, J.; Pettersson, H.B.L. [Linkoeping Univ. (Sweden). Dept. of Radiation Physics; Faelth-Magnusson, K. [University of Linkoeping (Sweden). Faculty of Health Sciences

    1995-12-31

    In paediatric patients, fluoroscopy is used to monitor intestinal biopsies obtained for the diagnosis of coeliac disease. The radiation dose to the child is dependent on the equipment, the sedation of the patient and the experience of the operator. This study presents patient measurements from a national study in Sweden. The cancer excess lifetime mortality risk (CELMR) and the loss of life expectancy (LLE) are calculated for this patient group. TLD measurements were performed by dosemeters at 40 Swedish paediatric departments performing these biopsies. Information was received on sedation techniques, equipment used and fluoroscopy duration. An exponential curve fit was applied to the entrance and exit dose values and this dose distribution was integrated to get the integral dose. From this the mean absorbed dose in the irradiated volume was calculated. The mean and the median of the mean absorbed dose in the irradiated volume to the children was found to be 1.3 mGy (range 0.05-17.5 mGy) and 0.56 mGy respectively. The mean value of the entrance surface dose was 3.0 mGy (range 0.10-27.1 mGy) and the median was 1.4 mGy. The annual collective dose was calculated to 3.3 man Gy, based on 2500 biopsies per year. Variation in doses was found to depend on, e.g. the age of the equipment, focus to patient distance, sedation and operator experience. With this knowledge of doses received by the children in the diagnosis of coeliac disease, CELMR was found to be 0.5 per 25000 biopsies and LLE was 18 years. Recommendations are given on the proper choice of equipment for the reduction of fluoroscopy doses in pediatric radiology. (Author).

  3. Absorbed organ and effective doses from digital intra-oral and panoramic radiography applying the ICRP 103 recommendations for effective dose estimations.

    Science.gov (United States)

    Granlund, Christina; Thilander-Klang, Anne; Ylhan, Betȕl; Lofthag-Hansen, Sara; Ekestubbe, Annika

    2016-10-01

    During dental radiography, the salivary and thyroid glands are at radiation risk. In 2007, the International Commission on Radiological Protection (ICRP) updated the methodology for determining the effective dose, and the salivary glands were assigned tissue-specific weighting factors for the first time. The aims of this study were to determine the absorbed dose to the organs and to calculate, applying the ICRP publication 103 tissue-weighting factors, the effective doses delivered during digital intraoral and panoramic radiography. Thermoluminescent dosemeter measurements were performed on an anthropomorphic head and neck phantom. The organ-absorbed doses were measured at 30 locations, representing different radiosensitive organs in the head and neck, and the effective dose was calculated according to the ICRP recommendations. The salivary glands and the oral mucosa received the highest absorbed doses from both intraoral and panoramic radiography. The effective dose from a full-mouth intraoral examination was 15 μSv and for panoramic radiography, the effective dose was in the range of 19-75 μSv, depending on the panoramic equipment used. The effective dose from a full-mouth intraoral examination is lower and that from panoramic radiography is higher than previously reported. Clinicians should be aware of the higher effective dose delivered during panoramic radiography and the risk-benefit profile of this technique must be assessed for the individual patient. The effective dose of radiation from panoramic radiography is higher than previously reported and there is large variability in the delivered radiation dosage among the different types of equipment used.

  4. Hand exposure of workers in (18)F-FDG production centre.

    Science.gov (United States)

    Wrzesień, Małgorzata; Albiniak, Łukasz

    2016-12-01

    (18)F-FDG is the most popular radiopharmaceutical used, among others, in oncological diagnostics by PET technique. The production of (18)F-FDG is a multistep process that begins by obtaining the radioisotope (18)F, and subsequently labelling the radiopharmaceutical, as well as quality control of the resulting compound. In each of these stages, the employee has contact with ionizing radiation. The production of (18)F requires the use of a cyclotron device. Currently in Poland, there are 9 centres equipped with a cyclotron for the production of positron-emitting radioisotopes. The monitoring of the occupational exposure to ionizing radiation in these centres is performed by measuring the effective and equivalent dose. Neither of these forms fully reflects the exposure of the worker, which is largely associated with handling procedures. The (18)F radiopharmaceutical preparation process runs automatically, which partially reduces the level of staff exposure, but the quality control step of the pharmaceutical requires handling procedures with a vial containing an activity of a radiopharmaceutical ranging from 4 GBq to 10 GBq. In the work presented, measurements were performed of hand exposure, in units the equivalent dose (H p (0.07)), of the staff who are involved in the procedures of (18)F-FDG production in one of the national production centres. The high-sensitivity thermoluminescent detectors (MCP) were used to measure the doses. The measurements were performed for three groups of workers: operators of the cyclotron, those who produce the (18)F-FDG, and quality control staff. Detectors were placed on the fingertips of the left and right hand, as well as in a standard ring dosemeter location. The results indicate that the largest exposure happens among the group of workers involved in the radiopharmaceutical's quality control. The doses recorded by the MCP detectors placed on the fingertips during one working day reach a value up to 2 mSv, which may result in

  5. SU-E-T-623: Polarity Effects for Small Volume Ionization Chambers in Cobalt-60 Beams

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y; Bhatnagar, J; Huq, M Saiful [Department of Radiation Oncology, University of Pittsburgh Cancer Institute and UPMC Cancer Center, Pittsburgh, PA (United States)

    2015-06-15

    Purpose: To investigate the polarity effects for small volume ionization chambers in {sup 60}Co gamma-ray beams using the Leksell Gamma Knife Perfexion. Methods: Measurements were made for 7 small volume ionization chambers (a PTW 31016, an Exradin A14, 2 Capintec PR0-5P, and 3 Exradin A16) using a PTW UNIDOSwebline Universal Dosemeter and an ELEKTA solid water phantom with proper inserts. For each ion chamber, the temperature/pressure corrected electric charge readings were obtained for 16 voltage values (±50V, ±100V, ±200V, ±300V, ±400V, ±500V, ±600V, ±700V). For each voltage, a five-minute leakage charge reading and a series of 2-minute readings were continuously taken during irradiation until 5 stable signals (less than 0.05% variation) were obtained. The average of the 5 reading was then used for the calculation of the polarity corrections at the voltage and for generating the saturation curves. Results: The polarity effects are more pronounced at high or low voltages than at the medium voltages for all chambers studied. The voltage dependence of the 3 Exradin A16 chambers is similar in shape. The polarity corrections for the Exradin A16 chambers changes rapidly from about 1 at 500V to about 0.98 at 700V. The polarity corrections for the 7 ion chambers at 300V are in the range from 0.9925 (for the PTW31016) to 1.0035 (for an Exradin A16). Conclusion: The polarity corrections for certain micro-chambers are large even at normal operating voltage.

  6. Intercomparison of radiation protection devices in a high-energy stray neutron field, Part II: Bonner sphere spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wiegel, B., E-mail: burkhard.wiegel@ptb.d [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany); Agosteo, S. [Politecnico of Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Bedogni, R. [INFN Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati (Italy); Caresana, M. [Politecnico of Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Esposito, A. [INFN Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati (Italy); Fehrenbacher, G. [Gesellschaft fuer Schwerionenforschung mbH, Planckstrasse 1, 64291 Darmstadt (Germany); Ferrarini, M. [Politecnico of Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Hohmann, E. [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany); Hranitzky, C. [Austrian Research Centers GmbH-ARC, 2444 Seibersdorf (Austria); Kasper, A.; Khurana, S. [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany); Mares, V. [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstrasse 1, 85764 Neuherberg (Germany); Reginatto, M. [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany); Rollet, S. [Austrian Research Centers GmbH-ARC, 2444 Seibersdorf (Austria); Ruehm, W. [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstrasse 1, 85764 Neuherberg (Germany); Schardt, D. [Gesellschaft fuer Schwerionenforschung mbH, Planckstrasse 1, 64291 Darmstadt (Germany); Silari, M. [CERN, 1211 Geneva 23 (Switzerland); Simmer, G.; Weitzenegger, E. [Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstrasse 1, 85764 Neuherberg (Germany)

    2009-08-15

    The European Commission has funded within its 6th Framework Programme a three-year project (2005-2007) called CONRAD, COordinated Network for RAdiation Dosimetry. A major task of the CONRAD Work Package 'complex mixed radiation fields at workplaces' was to organise a benchmark exercise in a workplace field at a high-energy particle accelerator where neutrons are the dominant radiation component. The CONRAD benchmark exercise took place at the Gesellschaft fuer Schwerionenforschung mbH (GSI) in Darmstadt, Germany in July 2006. In this paper, the results of the spectrometry using four extended -range Bonner sphere spectrometers of four different institutes are reported. Outside Cave A the neutron spectra were measured with three spectrometers at six selected positions and ambient dose equivalent values were derived for use in the intercomparison with other area monitors and dosemeters. At a common position all three spectrometers were used to allow a direct comparison of their results which acts as an internal quality assurance. The comparison of the neutron spectra measured by the different groups shows very good agreement. A detailed analysis presents some differences between the shapes of the spectra and possible sources of these differences are discussed. However, the ability of Bonner sphere spectrometers to provide reliable integral quantities like fluence and ambient dose equivalent is well demonstrated in this exercise. The fluence and dose results derived by the three groups agree very well within the given uncertainties, not only with respect to the total energy region present in this environment but also for selected energy regions which contribute in certain strength to the total values. In addition to the positions outside Cave A one spectrometer was used to measure the neutron spectrum at one position in the entry maze of Cave A. In this case a comparison was possible to earlier measurements.

  7. Monthly Record Tables, December 1998, with Supplement for the 4. quarter 1998; Tableaux mensuels des mesures, Decembre 1998, avec supplement relatif au 4-eme trimestre 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This report, issued under the aegis of O.P.R.I. (Office of protection against ionizing radiations), contains the activity level measurements of the radiation monitoring units throughout the country recorded in December 1998. A supplement contains the data relative to the 4. quarter is also added. Data relative toatmospheric sampling refer to surface and high altitude air as well as to atmospheric tritium concentration at Valduc. For rain water, dry fallout and deposition at soil level weekly sampling were carried out and monthly surveillance is reported. The drinking, surface and ground water measurements are reported for nuclear and non-nuclear sites. Measurement on food chains refer to cow milk, thyroids of horned cattle and fishes in the national market. Activity levels of given radioisotopes are given for vegetables and coastal sea waters as well as for waste and rain waters. Surveillance of wastes from facilities other than basic nuclear units (hospitals, research units, etc) was measured downstream to large cities in waste waters, rivers, sediments and aquatic flora. Sanitary controls on food and environment are reported as well as those carried out on workers and on operators implied in 6 nuclear incidents without consequences which occurred in December 1998 in French NPPs. The quarterly results refer to the following 16 items: 1. Radioactivity inventory in feedwater (Calvados); 2.Drinking waters; 3.Hydro-mineral sources; 4.Sea medium at Nord-Cotentin; 5.Surveillance of major National Navy facilities; 6.Surveillance of CNPE at Gravelines; 7. Surveillance of CNPE at Civaux; 8.Surveillance of COGEMA site at Marcoule; 9.Marine fauna and flora; 10.Surveillance of rice fields at Camargue; 11.Surveillance of sea sediments in Seine mouth; 12.Controlled releases; 13.Food chains; 14.Animal bones; 15.Soils; 16.Integrating dosemeters.

  8. A system for rapid large-area monitoring of gamma dose rates in the environment based on MCP-N (LiF:Mg,Cu,P) TL detectors.

    Science.gov (United States)

    Budzanowski, M; Olko, P; Ryba, E; Woźnicka, U

    2002-01-01

    One lesson learned from the Chernobyl accident was that the spatial distribution of far-field contamination was strongly non-uniform due to local variation of atmospheric conditions, such as wind direction, rain etc. An environmental monitoring system using highly sensitive thermoluminescent LiF:Mg,Cu,P (MCP-N) detectors has been completed and field-tested. The system consists of 3000 MCP-N detectors in 1000 TLD cards (three TLDs per card), two Mikrolab automatic TL readers, heating ovens, and specially developed software which includes a database for rapid evaluation of results. The main dosimetric parameters of MCP-N dosemeters, such as thermally-induced fading, light sensitivity, minimum detectable dose, self-dose, zero-dose, energy response up to 6-7 MeV, influence of annealing and readout conditions on detector stability, have been tested. About 100 locations over an area of about 15,000 km2 in the south of Poland were selected for measurements lasting from 4 days to 3 months. The kerma rates measured over a 4 day screening period agree well with kerma rates determined over a 75 day monitoring period. Results from short- and long-term exposure periods agree well with those performed using MTS-N (LiF:Mg,Ti) over southern Poland in 1985, before the Chernobyl accident. Thus, using the system based on MCP-N detectors, one is able simultaneously to monitor environmental radiation kerma rates at a large number of locations over periods of four days or less. Provided natural background kerma rates at selected monitoring points are available prior to the accident, the system can be applied to assess kerma rates rapidly in the environment, following a nuclear accident.

  9. Pre- and post-irradiation fading effect for LiF:Mg,Ti and LiF:Mg,Cu,P materials used in routine monitoring.

    Science.gov (United States)

    Carinou, E; Askounis, P; Dimitropoulou, F; Kiranos, G; Kyrgiakou, H; Nirgianaki, E; Papadomarkaki, E; Kamenopoulou, V

    2011-03-01

    LiF is a well-known thermoluminescent (TL) material used in individual monitoring, and its fading characteristics have been studied for years. In the present study, the fading characteristics (for a period of 150 d) of various commercial LiF materials with different dopants have been evaluated. The materials used in the study are those used in routine procedures by the Personal Dosimetry Department of Greek Atomic Energy Commission and in particular, LiF:Mg,Ti (MTS-N, TL Poland), LiF:Mg,Cu,P (MCP-N, TL Poland), LiF:Mg,Cu,P (MCP-Ns, thin active layer detector, TL Poland) and LiF:Mg,Cu,P (TLD100H, Harshaw). The study showed that there is a sensitivity loss in signal of up to 20 % for the MTS-N material for a 150-d period in the pre-irradiation fading phase. The MCP-N has a stable behaviour in the pre-irradiation fading phase, but this also depends on the readout system. As far as the post-irradiation fading effect is concerned, a decrease of up to 20 % for the MTS-N material is observed for the same time period. On the other hand, the LiF:Mg,Cu,P material presents a stable behaviour within ± 5 %. These results show that the fading effect is different for each material and should be taken into account when estimating doses from dosemeters that are in use for >2 months.

  10. X-ray effects on karyotype of Drosophila pseudo obscure. Pilot experience; Efecto de los rayos X en el cariotipo de Drosophila pseudoobscura. Experimento piloto

    Energy Technology Data Exchange (ETDEWEB)

    Salceda, V. M. [ININ, Departamento de Biologia, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)], e-mail: victor.salceda@inin.gob.mx

    2009-10-15

    Four groups of 100 males of Drosophila pseudo obscure carriers of genetic sequence Tree Line were treated with X-rays, through the use of a X-ray equipment Phillips MCN321; with absorbed individual doses of 28.2 Gy, 37.6 Gy, 47.6 Gy and 56.4 Gy, once irradiated these were crossed individually with two or three virgin females of the same constitution and the descendant emergency was took a larva of each crossing in order to detect the radiation effect on karyotype Tree Line of these organisms, chromosomal aberrations fundamentally, as well as on masculine sterility. Our observations gave as result for smaller dose, in a total of 61 analyzed larva, the obtaining of seven translocations equivalent to 11.5% as well as an inversion of 1.6%; with the following dose (58 analyzed larva) were obtained four translocations equal to 6.9%, two corresponding inversions to 3.4%, a mosaic and a deletion equivalent to 1.7%; with the dose of 47.6 Gy four translocations were induced 6.8% and deletion corresponding to 1.1%, again two respective inversions to 3.4% and a mosaic 1.7% in 59 analyzed larvas, meantime with the dose of 56.4 Gy appeared two translocations only equal to 3.7% in a sample of 54 individuals. The effect about masculine sterility was equal that the witness of 12% and for two following doses and finally of 41 and 46% respectively for the remaining doses. Comparisons with another authors gave similar values in the total cases. In accordance with our main objective, it is suggested to increase the sample size and to repeat the experiments using different genetic sequences as well as the possibility to use different radiation sources like gamma radiation and this way to utilize this system like a biological dosemeter. (Author)

  11. PAEDIATRIC NECK MULTIDETECTOR COMPUTED TOMOGRAPHY: THE EFFECT OF BISMUTH SHIELDING ON THYROID DOSE AND IMAGE QUALITY.

    Science.gov (United States)

    Inkoom, Stephen; Papadakis, Antonios E; Raissaki, Maria; Perisinakis, Kostas; Schandorf, Cyril; Fletcher, John J; Damilakis, John

    2017-04-15

    This study investigated the effect of bismuth shielding on thyroid dose and image quality in paediatric neck multidetector computed tomography (MDCT) performed with fixed tube current (FTC) and automatic exposure control (AEC). Four paediatric anthropomorphic phantoms representing the equivalent newborn, 1-, 5- and 10-y-old child were subjected to neck CT using a 16-slice MDCT system. Each scan was performed without and with single- and double-layered bismuth shield placed on the skin surface above the thyroid. Scans were repeated with cotton spacers of 1, 2 and 3 cm thick placed between the skin and shield, to study the effect of skin-to-shielding distance on image noise. Thyroid dose was measured with thermoluminescent dosemeters. The location of the thyroid within the phantom slices was determined by anthropometric data from patients' CT examinations whose body stature closely matched the phantoms. Effective dose (E) was estimated using the dose-length product (DLP) method. Image quality of resulted CT images was assessed through the image noise. Activation of AEC was found to decrease the thyroid dose by 46 % to the 10-y-old phantom subjected to neck CT. When FTC technique is used, single- and double-layered bismuth shielding was found to reduce the thyroid dose to the same phantom by 35 and 47 %, respectively. The corresponding reductions in AEC-activated scans were 60 and 66 %, respectively. Elevation of shields by 1-, 2- and 3-cm cotton spacers decreased the image noise by 69, 87 and 92 %, respectively, for single-layered FTC, without considerably affecting the thyroid dose. AEC was more effective in thyroid dose reduction than in-plane bismuth shields. Application of cotton spacers had no significant impact on thyroid dose, but significantly decreased the image noise. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Indirect measurements of X-ray spectra; Mediciones indirectas de espectros de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Mainardi, R.T. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, X5000HUA Cordoba (Argentina)

    2006-07-01

    To the effects of measuring the spectral distribution of the radiation emitted by the x-ray tubes and electron accelerators, numerous procedures that are grouped in two big categories exist at the present time: direct and indirect methods. The first ones use high resolution detectors that should be positioned, together with the appropriate collimator, in the direction of the x ray beam. The user should be an expert in the use and correction of the obtained data by the different effects that affect the detector operation such as efficiency and resolution in terms of the energy of the detected radiation. The indirect procedures, although its are more simple to use, its also require a considerable space along the beam to position the ionization chamber and the necessary absorbents to construct by this way the denominated attenuation curve. We will analyze the operation principle of the indirect methods and a new proposal in which such important novelties are introduced as the beam dispersion to avoid to measure along the main beam and that of determination of the attenuation curve in simultaneous form. By this way, with a single shot of the tube, the attenuation curve is measured, being necessary at most a shot of additional calibration to know the relative response of the detectors used in the experimental array. The physical processes involved in the obtaining of an attenuation curve are very well well-known and this it finishes it can be theoretically calculated if the analytic form of the spectrum is supposed well-known. Finally, we will see a spectra reconstruction example with the Kramers parametric form and comparisons with numeric simulations carried out with broadly validated programs as well as the possibility of the use of solid state dosemeters in the obtention of the attenuation curve. (Author)

  13. Dose due to {sup 40}K

    Energy Technology Data Exchange (ETDEWEB)

    Escareno J, E.; Vega C, H. R., E-mail: edmundoej@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2011-10-15

    The dose due to {sup 40}K has been estimated. Potassium is one of the most abundant elements in nature, being approximately 2% of the Earth's crust. Potassium has three isotopes {sup 39}K, {sup 40}K and {sup 41}K, two are stable while {sup 40}K is radioactive with a half life of 1.2x10{sup 9} years; there is 0.0117% {sup 40}K-to-K ratio. Potassium plays an important role in plants, animals and humans growth and reproduction. Due to the fact that K is an essential element for humans, {sup 40}K is the most abundant radioisotope in human body. In order to keep good health conditions K must be intake at daily basis trough food and beverages, however when K in ingested above the requirements produce adverse health effects in persons with renal, cardiac and hypertension problems or suffering diabetes. In 89.3% {sup 40}K decays to {sup 40}C through {beta}-decay, in 10.3% decays through electronic capture and emitting 1.46 MeV {gamma}-ray. K is abundant in soil, construction materials, sand thus {gamma}-rays produced during {sup 40}K decay contribute to external dose. For K in the body practically all {sup 40}K decaying energy is absorbed by the body; thus {sup 40}K contributes to total dose in humans and it is important to evaluate its contribution. In this work a set of {sup 40}K sources were prepared using different amounts of KCl salt, a {gamma}-ray spectrometer with a NaI(Tl) was characterized to standardized the sources in order to evaluate the dose due to {sup 40}K. Using thermoluminescent dosemeters the dose due to {sup 40}K was measured and related to the amount of {sup 40}K {gamma}-ray activity. (Author)

  14. Overview of novel techniques for radiation protection and dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Agosteo, Stefano, E-mail: stefano.agosteo@polimi.i [Politecnico of Milano, Dipartimento di Energia, Sezione di Ingegneria Nucleare - CeSNEF, via Ponzio 34/3, 20133 Milano (Italy); INFN, Sezione di Milano, via Celoria 16, 20133 Milano (Italy)

    2010-12-15

    Generally, the main approaches for assessing the radiation protection (RP) quantities in neutron fields are: i) the use of an instrument with a response to the protection quantity quasi-independent of energy; ii) neutron spectrometry; iii) microdosimetry. The techniques based on the first approach include rem-meters, superheated emulsions and the electronic personal dosemeters. Passive rem-meters have recently been developed for assessing the ambient dose equivalent in pulsed neutron fields around particle accelerators for hadrontherapy and research. Most of these instruments are characterised by a response extended to high-energies (up to a few GeV). An example is given by the GSI-ball, which employs a pair of LiF TLDs as a thermal neutron detector. It is likely that passive instruments will play a fundamental role also for monitoring the neutron fields generated by ultra-high intensity lasers, where the duration of a single pulse is of the order of hundreds femtoseconds. Arrays of tissue-equivalent proportional counters (TEPCs) of a millimetric/sub-millimetric physical size have been developed both for assessing the quality of therapeutic radiation beams and for estimating the RP quantities in low-intensity fields, which may limit the use of conventional microdosemeters. Very satisfactory results were obtained with GEM-based TEPCs and gas microstrip detectors (GMDs). Moreover, mini-TEPCs have been constructed and tested for measuring the quality of hadrontherapy beams (BNCT included). Silicon microdosemeters have also been demonstrated to be very promising for characterizing proton and ion beams for radiation therapy and for estimating the occurrence of single event effects in space applications.

  15. Simplified geometric model for the calculation of neutron yield in an accelerator of 18 MV for radiotherapy; Modelo geometrico simplificado para el calculo del rendimiento de neutrones en un acelerador de 18 MV para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.C.; Balcazar G, M. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico); Francois L, J.L. [FI-UNAM, 04510 Mexico D.F. (Mexico); Azorin N, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2008-07-01

    The results of the neutrons yield in different components of the bolster of an accelerator Varian Clinac 2100C of 18 MV for radiotherapy are presented, which contribute to the radiation of flight of neutrons in the patient and bolster planes. For the calculation of the neutrons yield, a simplified geometric model of spherical cell for the armor-plating of the bolster with Pb and W was used. Its were considered different materials for the Bremsstrahlung production and of neutrons produced through the photonuclear reactions and of electro disintegration, in function of the initial energy of the electron. The theoretical result of the total yield of neutrons is of 1.17x10{sup -3} n/e, considering to the choke in position of closed, in the patient plane with a distance source-surface of 100 cm; of which 15.73% corresponds to the target, 58.72% to the primary collimator, 4.53% to the levelled filter of Fe, 4.87% to the levelled filter of Ta and 16.15% to the closed choke. For an initial energy of the electrons of 18 MeV, a half energy of the neutrons of 2 MeV was obtained. The calculated values for radiation of experimental neutrons flight are inferior to the maxima limit specified in the NCRP-102 and IEC-60601-201.Ed.2.0 reports. The absorbed dose of neutrons determined through the measurements with TLD dosemeters in the isocenter to 100 cm of the target when the choke is closed one, is approximately 3 times greater that the calculated for armor-plating of W and 1.9 times greater than an armor-plating of Pb. (Author)

  16. Radon in Saudi houses

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Jarad, F.; Al-Jarallah, M.I.

    1986-01-01

    A total of 637 passive radon dosemeters (CR-39 nuclear track detectors in a closed chamber) were used in a survey in 400 houses in Saudi Arabia. The radon concentration was found to vary from 5 to 36 Bq.m/sup -3/ (0.13 to 0.98 pCi.l/sup -1/) with a mean of 16 Bq.m/sup -3/ (0.43 pCi.l/sup -1/). The unoccupied houses showed a concentration of 29+-7 Bq.m/sup -3/ (0.78+-0.19 pCi.l/sup -1/) double that of the occupied houses, 14+-1 Bq.m/sup -3/ (0.39+-0.02 pCi.l/sup -1/), in the same area. The radon daughter concentration measured with a Working Level monitor in 17 unoccupied houses was found to vary from 1.35x10/sup -3/ to 24x10/sup -3/ WL with an average of 6.9+-1.4x10/sup -3/ WL. The average exhalation rate measured in 37 houses by 95 passive detectors in cans sealed to the walls ranged from 0.013 to 0.044 Bq.m/sup -2/.h/sup -1/(0.35 to 1.2 pCi.m/sup -2/.h/sup -1/) with an average of 0.021+-0.003 Bq.m/sup -2/.h/sup -1/(0.56+-0.09 pCi.m/sup -2/.h/sup -1/). This survey is the first in Saudi Arabia (a hot climate) and can usefully be compared with similar surveys in countries with cold climates.

  17. Tl and OSL dosimetry of diamond films CVD pure and unpurified with boron-carbon; Dosimetria Tl y OSL de peliculas de diamante CVD puras e impurificadas con boro-carbono

    Energy Technology Data Exchange (ETDEWEB)

    Melendrez, R.; Pedroza M, M.; Chernov, V.; Ochoa N, J.D.; Bernal, R.; Barboza F, M. [CIF, UNISON, A.P. 5-088, 83190 Hermosillo, Sonora (Mexico); Castaneda, B. [Departamento de Fisica, Universidad de Sonora, Apdo. Postal 1626, Hermosillo, Sonora (Mexico); Goncalves, J.A.N.; Sandonato, G.M. [Laboratorio Associado de Plasma, Instituto Nacional de Pesquisas Espaciais C.P. 515- 12201 -970, Sao Jose dos Campos, SP (Brazil); Cruz Z, E. [Instituto de Ciencias Nucleares, UNAM, Apdo. Postal 70-543, 04510 Mexico D.F. (Mexico); Preciado F, S.; Cruz V, C.; Brown, F. [Departamento de Investigacion en Polimeros y Materiales de la Universidad de Sonora, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Schreck, M. [Universitaet Augsburg, Institut fuer Physik D-86135 Augsburg (Germany)

    2004-07-01

    The diamond is a material that possesses extreme physical properties, such as its hardness to the radiation, its low chemical reactivity besides its equivalence to the human tissue, which qualify him as an ideal material for radiation dosimetry. In this work, it was studied the thermal and optically stimulated response (Tl and OSL) of polycrystalline diamond films grown by the technique of CVD pure and contaminated with Boron-carbon (B/C) with the intention of characterizing their efficiency like a dosemeter for radiation in a range of 0 - 3000 Gy. For the case of the films without impurities, the Tl curve presents four main peaks, two of them in an interval of temperatures of 150-200 C and other two additional around of 250-400 C. The dependence of the response of integrated Tl and that of OSL always maintained a lineal relationship with the exhibition dose up to 100 Gy. The behavior of the films contaminated with B/C (2000 - 20000 ppm) was established through experiments that involved the signal of OSL and their relationship with the Tl response. It was found that this processes are correlated, since the electrons caught in the traps of low temperature (50 - 250 C) of the Tl they are the electrons that recombining with more probability to provide the signal of OSL. According to these results it is possible to propose the diamond films as a good candidate for dosimetry to, using the traditional technique of Tl so much as well as the but recent of OSL. (Author)

  18. Influence of lead apron shielding on absorbed doses from panoramic radiography.

    Science.gov (United States)

    Rottke, D; Grossekettler, L; Sawada, K; Poxleitner, P; Schulze, D

    2013-01-01

    This study investigated the absorbed doses in a full anthropomorphic body phantom from two different panoramic radiography devices, performing protocols with and without applying a lead apron. A RANDO(®) full body phantom (Alderson Research Laboratories Inc., Stamford, CT) was equipped with 110 thermoluminescent dosemeters at 55 different sites and set up in two different panoramic radiography devices [SCANORA(®) three-dimensional (3D) (SOREDEX, Tuusula, Finland) and ProMax(®) 3D (Planmeca, Helsinki, Finland)] and exposed. Two different protocols were performed in the two devices. The first protocol was performed without any lead shielding, whereas the phantom was equipped with a standard adult lead apron for the second protocol. A two-tailed paired samples t-test for the SCANORA 3D revealed that there is no difference between the protocol using lead apron shielding (m = 87.99, s = 102.98) and the protocol without shielding (m = 87.34, s = 107.49), t(54) = -0.313, p > 0.05. The same test for the ProMax 3D showed that there is also no difference between the protocol using shielding (m = 106.48, s = 117.38) and the protocol without shielding (m = 107.75, s = 114,36), t(54) = 0.938, p > 0.05. In conclusion, the results of this study showed no statistically significant differences between a panoramic radiography with or without the use of lead apron shielding.

  19. Preliminary assessment of the dose to the interventional radiologist in fluoro-CT-guided procedures.

    Science.gov (United States)

    Pereira, M F; Alves, J G; Sarmento, S; Santos, J A M; Sousa, M J; Gouvêa, M; Oliveira, A D; Cardoso, J V; Santos, L M

    2011-03-01

    A preliminary assessment of the occupational dose to the intervention radiologist received in fluoroscopy computerised tomography (CT) used to guide the collection of lung and bone biopsies is presented. The main aim of this work was to evaluate the capability of the reading system as well as of the available whole-body (WB) and extremity dosemeters used in routine monthly monitoring periods to measure per procedure dose values. The intervention radiologist was allocated 10 WB detectors (LiF: Mg, Ti, TLD-100) placed at chest and abdomen levels above and below the lead apron, and at both right and left arms, knees and feet. A special glove was developed with casings for the insertion of 11 extremity detectors (LiF:Mg, Cu, P, TLD-100H) for the identification of the most highly exposed fingers. The H(p)(10) dose values received above the lead apron (ranged 0.20-0.02 mSv) depend mainly on the duration of the examination and on the placement of physician relative to the beam, while values below the apron are relatively low. The left arm seems to receive a higher dose value. H(p)(0.07) values to the hand (ranged 36.30-0.06 mSv) show that the index, middle and ring fingers are the most highly exposed. In this study, the wrist dose was negligible compared with the finger dose. These results are preliminary and further studies are needed to better characterise the dose assessment in CT fluoroscopy.

  20. Efficacy of Lens Protection Systems: Dependency on Different Cranial CT Scans in The Acute Stroke Setting.

    Science.gov (United States)

    Guberina, Nika; Forsting, Michael; Ringelstein, Adrian

    2017-06-15

    To evaluate the dose-reduction potential with different lens protectors for patients undergoing cranial computed tomography (CT) scans. Eye lens dose was assessed in vitro (α-Al2O3:C thermoluminescence dosemeters) using an Alderson-Rando phantom® in cranial CT protocols at different CT scanners (SOMATOM-Definition-AS+®(CT1) and SOMATOM-Definition-Flash® (CT2)) using two different lens-protection systems (Somatex® (SOM) and Medical Imaging Systems® (MIS)). Summarised percentage of the transmitted photons: (1) CT1 (a) unenhanced CT (nCT) with gantry angulation: SOM = 103%, MIS = 111%; (2) CT2 (a) nCT without gantry angulation: SOM = 81%, MIS = 91%; (b) CT angiography (CTA) with automatic dose-modulation technique: SOM = 39%, MIS = 74%; (c) CTA without dose-modulation technique: SOM = 22%, MIS = 48%; (d) CT perfusion: SOM = 44%, MIS = 69%. SOM showed a higher dose-reduction potential than MIS maintaining equal image quality. Lens-protection systems are most effective in CTA protocols without dose-reduction techniques. Lens-protection systems lower the average eye lens dose during CT scans up to 1/3 (MIS) and 2/3 (SOM), respectively, if the eye lens is exposed to the direct beam of radiation. Considering both the CT protocol and the material of lens protectors, they seem to be mandatory for reducing the radiation exposure of the eye lens. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Measurements of long-term external and internal radiation exposure of inhabitants of some villages of the Bryansk region of Russia after the Chernobyl accident.

    Science.gov (United States)

    Bernhardsson, C; Zvonova, I; Rääf, C; Mattsson, S

    2011-10-15

    A Nordic-Soviet programme was initiated in 1990 to evaluate the external and internal radiation exposure of the inhabitants of several villages in the Bryansk region of Russia. This area was one of the number of areas particularly affected by the nuclear accident at the Chernobyl Nuclear Power Plant in 1986. Measurements were carried out yearly until 1998 and after that more irregularly; in 2000, 2006 and 2008 respectively. The effective dose estimates were based on individual thermoluminescent dosemeters and on in vivo measurements of the whole body content of (137)Cs (and (134)Cs during the first years of the programme). The decrease in total effective dose during the almost 2 decade follow-up was due to a continuous decrease in the dominating external exposure and a less decreasing but highly variable exposure from internal irradiation. In 2008, the observed average effective dose (i.e. the sum of external and internal exposure) from Chernobyl (137)Cs to the residents was estimated to be 0.3mSv y(-1). This corresponds to 8% of the estimated annual dose in 1990 and to 1% of the estimated annual dose in 1986. As a mean for the population group and for the period of the present study (2006-2008), the average yearly effective dose from Chernobyl cesium was comparable to the absorbed dose obtained annually from external exposure to cosmic radiation plus internal exposure to naturally occurring radionuclides in the human body. Our data indicate that the effective dose from internal exposure is becoming increasingly important as the body burdens of Chernobyl (137)Cs are decreasing more slowly than the external exposure. However, over the years there have been large individual variations in both the external and internal effective doses, as well as differences between the villages investigated. These variations and differences are presented and discussed in this paper. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Thermoluminescent characteristics (TL) of K{sub 2}F{sub 5}: Y{sub 0.99} Tb{sub 0.01} irradiated with beta particles of {sup 90}Sr/{sup 90} Y; Caracteristicas termoluminiscentes (TL) de K{sub 2}F{sub 5}: Y{sub 0.99} Tb{sub 0.01} irradiado con particulas beta de {sup 90}Sr/{sup 90} Y

    Energy Technology Data Exchange (ETDEWEB)

    Baillet, C.; Azorin, J.; Rivera, T. [Dep. de Fisica, UAM-I, 09340 Mexico D.F. (Mexico)

    2005-07-01

    In this work the results of studying the thermoluminescent characteristics of the K{sub 2}F{sub 5}: Y{sub 0.99} Tb{sub 0.01} are presented. The material was characterized irradiating samples of K{sub 2}F{sub 5}: Y{sub 0.99}Tb{sub 0.01} in powder with beta radiation of {sup 90}Sr/{sup 90}Y. The studied characteristics were TL curve, response reproducibility, TL response in function of the dose and fading of the information. The samples exhibited a thermoluminescent curve (TL) with two very defined peaks centered respectively in 167 and 307 C. The TL response of the samples under the action of the beta radiation after 10 cycles (thermal erased, irradiation and reading of the samples) presented a standard deviation of 3.09%. The TL response of K{sub 2}F{sub 5}: Y{sub 0.99} Tb{sub 0.01} in function of the absorbed dose of beta radiation resulted lineal in the interval of 3 mGy to 1.29 Gy. The fading of the information contained in the samples of K{sub 2}F{sub 5}: Y{sub 0.99} Tb{sub 0.01} was of 40% in the first 10 minutes, which is due to the first peak. The obtained results suggest that the TL material resulted as promissory for its possible use as thermoluminescent dosemeter of beta radiation using the second peak of its TL curve like dosimetric peak. (Author)

  3. Dosimetric evaluation in panoramic and tele-radiography procedures; Avaliacao dosimetrica em procedimentos de radiografia panoramica e teleradiografias

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Georgge Gomes

    2004-07-01

    The present work had as an objective to evaluate the skin surface entrance dose in panoramic and tele radiography procedures in three clinics in Recife - Pernambuco - Brazil, and to contribute with data for the determination of reference levels for super cited extra oral procedures, for this purpose, operational conditions in 3 clinics were evaluated in Recife, aiming to evaluate the existence and integrity of the radioprotection equipment, manner and conditions of image processing; and radiographic equipment parameters such as the dimension of the irradiation filed, the total filtration, the exposure time and the potential applied to the X ray tube. For an estimation of the skin entrance dose of the patient, the phantom Randon Alderson and thermoluminescence dosemeters were used. From these values and the conversion factors determined by the Monte Carlo technique, with the phantom MAX it was possible to estimate the dose absorbed in the organ due to the tele radiography procedures. Regarding panoramic radiography the study showed that the more elevated doses occurred in the parotid gland region which is near rotational venters. In the case of tele radiography the highest dose value occurred in the regions corresponding to the temporal lobe of the brain, followed by linfonodes, ears and parotid glands. The doses absorbed in the eyes and the thyroid gland were, 0.037 mGy and 0.002 mGy in Clinic A and 0.062 mGy and 0.003 mGy in Clinic C, respectively. Regarding equipment test, inadequacy was found in the beam collimation in Clinic A and in the reproducibility of the X ray exposure in Clinic C. The total filtration in both clinics was inadequate.(author)

  4. The thermoluminescence as tool in the reconstruction of volcanic events; La termoluminiscencia como herramienta en la reconstruccion de eventos volcanicos

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez L, A.; Schaaf, P.; Martin del Pozzo, A.L.; Gonzalez M, P. [Instituto de Geofisica, UNAM, C.P. 04500, Mexico D.F. (Mexico)

    2000-07-01

    Within the Mexican land a great number of volcanoes are situated which a considerable part of them are still active. The relevance of dating pomex deposits, ash or lava of these poly genetic volcanoes is to determine the periodicity and magnitude of the volcanic events happened. In this work is presented the preliminary result of the dating by thermoluminescence in a pomex of a pyroclastic flux coming from a volcano in the state of Puebla with the purpose of providing elements to the knowledge which describe the eruptive history of the explosive volcanism at center of Mexico. For the sample dating the volcanic glasses of pomex were separated and it was applied the fine grain technique with a grain size between 4-11 {mu} m. In order to calculate the rate of annual dose it was carried out the following: in the determination of {sup 238} U and {sup 232} Th radioisotope concentration was used the neutron activation technique in a nuclear reactor, in the determination of the K 40 radioisotope was used a scanning electron microscope, the rate of environmental and cosmic dose was measured arranging Tl dosemeters of CaSO{sub 4}: Dy in the sampling place. In order to calculate the paleodoses it was carried out the following: the equivalent dose (Q) was determined starting form the additive method and the supra linearity factor (I) starting from regenerative method and in both methods the irradiated process was realized with a {sup 90} Sr beta source. With the above determinations it was calculated a paleodoses of 231 Gy and a rate of annual dose of 6.074 x 10{sup -3} Gy/year, estimating an age of: Age{sub pomez} = 231 Gy / 6.074 Gy x 10{sup -3} Gy /year = 38030 {+-} 4000 years. (Author)

  5. Absorbed organ and effective doses from digital intra-oral and panoramic radiography applying the ICRP 103 recommendations for effective dose estimations

    Science.gov (United States)

    Thilander-Klang, Anne; Ylhan, Betȕl; Lofthag-Hansen, Sara; Ekestubbe, Annika

    2016-01-01

    Objective: During dental radiography, the salivary and thyroid glands are at radiation risk. In 2007, the International Commission on Radiological Protection (ICRP) updated the methodology for determining the effective dose, and the salivary glands were assigned tissue-specific weighting factors for the first time. The aims of this study were to determine the absorbed dose to the organs and to calculate, applying the ICRP publication 103 tissue-weighting factors, the effective doses delivered during digital intraoral and panoramic radiography. Methods: Thermoluminescent dosemeter measurements were performed on an anthropomorphic head and neck phantom. The organ-absorbed doses were measured at 30 locations, representing different radiosensitive organs in the head and neck, and the effective dose was calculated according to the ICRP recommendations. Results: The salivary glands and the oral mucosa received the highest absorbed doses from both intraoral and panoramic radiography. The effective dose from a full-mouth intraoral examination was 15 μSv and for panoramic radiography, the effective dose was in the range of 19–75 μSv, depending on the panoramic equipment used. Conclusion: The effective dose from a full-mouth intraoral examination is lower and that from panoramic radiography is higher than previously reported. Clinicians should be aware of the higher effective dose delivered during panoramic radiography and the risk–benefit profile of this technique must be assessed for the individual patient. Advances in knowledge: The effective dose of radiation from panoramic radiography is higher than previously reported and there is large variability in the delivered radiation dosage among the different types of equipment used. PMID:27452261

  6. Measurements of long-term external and internal radiation exposure of inhabitants of some villages of the Bryansk region of Russia after the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Bernhardsson, C., E-mail: christian.bernhardsson@med.lu.se [Department of Clinical Sciences Malmoe, Medical Radiation Physics, Lund University, Skane University Hospital Malmoe, 205 02, Malmoe (Sweden); Zvonova, I. [Research Institute of Radiation Hygiene, ul. Mira, 8, 197101, St. Petersburg (Russian Federation); Raeaef, C.; Mattsson, S. [Department of Clinical Sciences Malmoe, Medical Radiation Physics, Lund University, Skane University Hospital Malmoe, 205 02, Malmoe (Sweden)

    2011-10-15

    A Nordic-Soviet programme was initiated in 1990 to evaluate the external and internal radiation exposure of the inhabitants of several villages in the Bryansk region of Russia. This area was one of the number of areas particularly affected by the nuclear accident at the Chernobyl Nuclear Power Plant in 1986. Measurements were carried out yearly until 1998 and after that more irregularly; in 2000, 2006 and 2008 respectively. The effective dose estimates were based on individual thermoluminescent dosemeters and on in vivo measurements of the whole body content of {sup 137}Cs (and {sup 134}Cs during the first years of the programme). The decrease in total effective dose during the almost 2 decade follow-up was due to a continuous decrease in the dominating external exposure and a less decreasing but highly variable exposure from internal irradiation. In 2008, the observed average effective dose (i.e. the sum of external and internal exposure) from Chernobyl {sup 137}Cs to the residents was estimated to be 0.3 mSv y{sup -1}. This corresponds to 8% of the estimated annual dose in 1990 and to 1% of the estimated annual dose in 1986. As a mean for the population group and for the period of the present study (2006-2008), the average yearly effective dose from Chernobyl cesium was comparable to the absorbed dose obtained annually from external exposure to cosmic radiation plus internal exposure to naturally occurring radionuclides in the human body. Our data indicate that the effective dose from internal exposure is becoming increasingly important as the body burdens of Chernobyl {sup 137}Cs are decreasing more slowly than the external exposure. However, over the years there have been large individual variations in both the external and internal effective doses, as well as differences between the villages investigated. These variations and differences are presented and discussed in this paper.

  7. TLD Intercomparison in accelerators for radiotherapy in three Latin american countries; Intercomparacion TLD en aceleradores para radioterapia en tres paises latinoamericanos

    Energy Technology Data Exchange (ETDEWEB)

    Gaona, E.; Azorin N, J.; Perez, M.A.; Picon, C.; Castellanos, E.; Plazas, M.C.; Murcia, G.; Archundia, L. [Depto. El Hombre y su Ambiente. Universidad Autonoma Metropolitana, Calz. Del Hueso 1100, 04960 Mexico D.F. (Mexico)

    1998-12-31

    In Radiotherapy one of the objectives is to establish and to give follow up to quality assurance programs which make sure that the doses administered to the patients with cancer are a high probability of a success in external radiation. Likewise, one of the present preoccupations of the United Nations Agencies as well as the International Atomic Energy Agency and the Pan-American Health Organization is the optimal employment of the radiations in the treatment of cancer patients since the administered dose in Radiotherapy suffers considerable variations by the lack of quality assurance programs. The use of Electron linear accelerators requires a program of quality assurance that includes expert personnel, equipment and adequate facilities. The more used methodology for the dosimetry calibration and characterization of X-ray beams and high energy electrons for radiotherapy use is using a ionization chamber dosemeter calibrated in a regional secondary standardization laboratory. However, to establish and give follow up to the quality assurance programs it is necessary the dosimetric intercomparison through TLD. In this study it was designed plastic phantoms with TLD crystals and it was made its characterization to realize an absorbed dose analysis in the crystals exposed at X-ray beams 6 MV and high energy electrons 10 and 12 MeV to standardize the dosimetric procedures and proceeding to realize an International Pilot intercomparison of absorbed doses in TLD crystals in three Latin American countries: Mexico, Peru and Colombia with the participation of accelerators of five different institutions. The found results show that the majority of the measured doses with TLD in the different accelerators were in the 0.95-1.05 range though it had two cases outside of this range. The use of the phantoms with TLD crystals shows that they are of excellent aid to make analysis of the doses administered to the patients and an intercomparison of results to standardize procedures at

  8. Pre-clinical evaluation of a diode-based In vivo dosimetry system

    Energy Technology Data Exchange (ETDEWEB)

    Trujillo, G. [National Oncology Institute, Havana (Cuba)

    1998-12-31

    Diode detector systems are routinely used in a number of departments for the quality assurance of the delivered dose in radiation oncology (1,2,3,4,5). The main advantage of diode detectors for in vivo dosimetry (over TLDs, film dosimetry, ionization chambers) is that results are immediately available in real time, do not need external bias voltage and are more sensitive for the same detection volume than ionization chambers thereby allowing a direct and immediate check of the treatment accuracy. Also, is important to mention that is possible to obtain different accuracy levels. For example, in the case of the measurements designed for evaluating the dosimetric accuracy of a new treatment technique for dose escalation studies the action level should be tighter (the order of 2 % to 4 %, 2 standard deviations) than for routine measurements aiming to discover and correct for errors in the treatment of individual patients ({+-} 5 % - 10 % or to avoid mis administrations (10 % - 15 %). This work describes the calibration method adopted and the evaluation of the accuracy and precision of in vivo dosimetry at Co 60 and 23 MV photon energies. Extensive phantoms measurements were made to determine the influence of physical conditions on the diode response. Parameters investigated included diode linearity, leakage, and measurement reproducibility, as well as the field size, SSD, and angular dependence. the practical consequences of these measurements are reported. There is still some controversy as to whether in vivo (diode) dosemeters are required for routine quality assurance purposes. Our work has shown that while care must be taken in choosing and handling diode detector systems they are able to provide an efficient and effective method of ensuring the dose delivered to the patient during treatment is within acceptable limits. (Author)

  9. SU-E-I-04: A Mammography Phantom to Measure Mean Glandular Dose and Image Quality

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Pineda, E; Ruiz-Trejo, C; E, Brandan M [Instituto de Fisica UNAM, Mexico City, DF (Mexico)

    2014-06-01

    Purpose: To evaluate mean glandular dose (MGD) and image quality in a selection of mammography systems using a novel phantom based on thermoluminescent dosemeters and the ACR wax insert. Methods: The phantom consists of two acrylic, 19 cm diameter, 4.5 cm thick, semicircular modules, used in sequence. The image quality module contains the ACR insert and is used to obtain a quality control image under automatic exposure conditions. The dosimetric module carries 15 TLD-100 chips, some under Al foils, to determine air kerma and half-value-layer. TL readings take place at our laboratory under controlled conditions. Calibration was performed using an ionization chamber and a Senographe 2000D unit for a variety of beam qualities, from 24 to 40 kV, Mo and Rh anodes and filters. Phantom MGD values agree, on the average, within 3% with ionization chamber data, and their precision is better than 10% (k=1). Results: MGD and image quality have been evaluated in a selection of mammography units currently used in Mexican health services. The sample includes analogic (screen/film), flexible digital (CR), and full-field digital image receptors. The highest MDG are associated to the CR technology. The most common image quality failure is due to artifacts (dust, intensifying screen scratches, and processor marks for film/screen, laser reader defects for CR). Conclusion: The developed phantom permits the MGD measurement without the need of a calibrated ionization chamber at the mammography site and can be used by a technician without the presence of a medical physicist. The results indicate the urgent need to establish quality control programs for mammography.

  10. Exposure to power-frequency electromagnetic fields in Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Skotte, J.H.

    1994-01-01

    The purpose of the study was to assess exposure to power-frequency electromagnetic fields in various groups with normal or high exposure in occupational and residential environments. Exposure to power-frequency (50 Hz) electric and magnetic fields was measured for 301 volunteers (396 measurements) in periods of 24 h in both occupational and residential environments. The study included electrical utility workers (generation, transmission, distribution, substation), office and industrial workers, and people living near high-power transmission lines. Electric and magnetic fields were measured with personal dosemeters, and the mean values were calculated for work and nonwork periods. The work-period magnetic field exposure, as the geometric mean of the distribution of the work-period means. for a group of selected industrial workers with high exposure was 6 [geometric standard deviation (GSD) 4.6] [mu]T. The exposure level was 0.10 (GSD 2.4) [mu]T for 'normal' industrial workers and 0.09 (GSD 1.8) [mu]T for office workers. For electrical utility workers the corresponding values were 0.72 (GSD 2.5) [mu]T for substation workers. 0.52 (GSD 4.2) [mu]T for generation workers. 0.36 (GSD 3.5) [mu]T for transmission workers, and 0.15 (GSD 2.9) [mu]T for distribution workers. The magnetic field exposure in normal residences was 0.04 (GSD 2.1) [mu]T, and in residences near high-power lines it was 0.29 (GSD 2.8) [mu]T. Corresponding results on exposure to electric fields are given in the study. All of the measurements of exposure to electric and magnetic fields were below the values normally used as guidelines

  11. Exposure to power-frequency electromagnetic fields in Denmark.

    Science.gov (United States)

    Skotte, J H

    1994-04-01

    The purpose of the study was to assess exposure to power-frequency electromagnetic fields in various groups with normal or high exposure in occupational and residential environments. Exposure to power-frequency (50 Hz) electric and magnetic fields was measured for 301 volunteers (396 measurements) in periods of 24 h in both occupational and residential environments. The study included electrical utility workers (generation, transmission, distribution, substation), office and industrial workers, and people living near high-power transmission lines. Electric and magnetic fields were measured with personal dosemeters, and the mean values were calculated for work and nonwork periods. The work-period magnetic field exposure, as the geometric mean of the distribution of the work-period means, for a group of selected industrial workers with high exposure was 6 [geometric standard deviation (GSD) 4.6] muT. The exposure level was 0.10 (GSD 2.4) muT for "normal" industrial workers and 0.09 (GSD 1.8) muT for office workers. For electrical utility workers the corresponding values were 0.72 (GSD 2.5) muT for substation workers, 0.52 (GSD 4.2) muT for generation workers, 0.36 (GSD 3.5) muT for transmission workers, and 0.15 (GSD 2.9) muT for distribution workers. The magnetic field exposure in normal residences was 0.04 (GSD 2.1) muT, and in residences near high-power lines it was 0.29 (GSD 2.8)muT. Corresponding results on exposure to electric fields are given in the study. All of the measurements of exposure to electric and magnetic fields were below the values normally used as guidelines.

  12. Peripheral photon and neutron doses from prostate cancer external beam irradiation.

    Science.gov (United States)

    Bezak, Eva; Takam, Rundgham; Marcu, Loredana G

    2015-12-01

    Peripheral photon and neutron doses from external beam radiotherapy (EBRT) are associated with increased risk of carcinogenesis in the out-of-field organs; thus, dose estimations of secondary radiation are imperative. Peripheral photon and neutron doses from EBRT of prostate carcinoma were measured in Rando phantom. (6)LiF:Mg,Cu,P and (7)LiF:Mg,Cu,P glass-rod thermoluminescence dosemeters (TLDs) were inserted in slices of a Rando phantom followed by exposure to 80 Gy with 18-MV photon four-field 3D-CRT technique. The TLDs were calibrated using 6- and 18-MV X-ray beam. Neutron dose equivalents measured with CR-39 etch-track detectors were used to derive readout-to-neutron dose conversion factor for (6)LiF:Mg,Cu,P TLDs. Average neutron dose equivalents per 1 Gy of isocentre dose were 3.8±0.9 mSv Gy(-1) for thyroid and 7.0±5.4 mSv Gy(-1) for colon. For photons, the average dose equivalents per 1 Gy of isocentre dose were 0.2±0.1 mSv Gy(-1) for thyroid and 8.1±9.7 mSv Gy(-1) for colon. Paired (6)LiF:Mg,Cu,P and (7)LiF:Mg,Cu,P TLDs can be used to measure photon and neutron doses simultaneously. Organs in close proximity to target received larger doses from photons than those from neutrons whereas distally located organs received higher neutron versus photon dose. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Individual dosimetry of workers and patients: implementation and perspectives; La dosimetrie individuelle des travailleurs et de patients: mise en oeuvre et perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Rannou, A.; Aubert, B.; Lahaye, Th.; Scaff, P.; Casanova, Ph.; Van Bladel, L.; Queinnec, F.; Valendru, N.; Jehanno, J.; Grude, E.; Berard, Ph.; Desbree, A.; Kafrouni, H.; Paquet, F.; Vanhavere, F.; Bridier, A.; Ginestet, Ch.; Magne, S.; Donadille, L.; Bordy, J.M.; Bottollier-Depois, J.F.; Barrere, J.L.; Ferragut, A.; Metivier, H.; Gaillard-Lecanu, E

    2008-07-01

    These days organised by the section of the technical protection of the S.F.R.P. review the different techniques of dosimetry used in France and Europe, and present the future orientations.The different interventions are as follow: Individual exposures of the workers: historic assessment and perspectives; medical exposure: where are the doses; legal obligations in individual dosimetry: which are the objective and the need on the subject; the dosimetry follow-up of workers by the S.I.S.E.R.I. system: assessment and perspectives; impact of the norm ISO 20553 on the follow-up of internal exposure; the implementation of the patient dose measurement in Belgium; techniques of passive dosimetry used in Europe; Supervision radiation protection at EDF: long term and short term approach; Comparison active and passive dosimetry at Melox; methodology for the choice of new neutron dosemeters; the working group M.E.D.O.R.: guide of internal dosimetry for the use of practitioners; O.E.D.I.P.E.: tool of modeling for the personalized internal dosimetry; the use of the Monte-Carlo method for the planning of the cancer treatment by radiotherapy becomes a reality; the works of the committee 2 of the ICRP; passive dosimetry versus operational dosimetry: situation in Europe; Implementation of the in vivo dosimetry in a radiotherapy department: experience of the Gustave Roussy institute; experience feedback on the in vivo measures in radiotherapy, based on the use of O.S.L. pellets; multi points O.S.L. instrumentation for the radiation dose monitoring in radiotherapy; dosimetry for extremities for medical applications: principle results of the European contract C.O.N.R.A.D.; references and perspectives in dosimetry; what perspectives for numerical dosimetry, an example: Sievert; system of dose management: how to answer to needs; the last technical evolutions in terms of electronic dosimetry in nuclear power plant; the fourth generation type reactors: what dosimetry. (N.C.)

  14. The influence of operator position, height and body orientation on eye lens dose in interventional radiology and cardiology: Monte Carlo simulations versus realistic clinical measurements.

    Science.gov (United States)

    Principi, S; Farah, J; Ferrari, P; Carinou, E; Clairand, I; Ginjaume, M

    2016-09-01

    This paper aims to provide some practical recommendations to reduce eye lens dose for workers exposed to X-rays in interventional cardiology and radiology and also to propose an eye lens correction factor when lead glasses are used. Monte Carlo simulations are used to study the variation of eye lens exposure with operator position, height and body orientation with respect to the patient and the X-ray tube. The paper also looks into the efficiency of wraparound lead glasses using simulations. Computation results are compared with experimental measurements performed in Spanish hospitals using eye lens dosemeters as well as with data from available literature. Simulations showed that left eye exposure is generally higher than the right eye, when the operator stands on the right side of the patient. Operator height can induce a strong dose decrease by up to a factor of 2 for the left eye for 10-cm-taller operators. Body rotation of the operator away from the tube by 45°-60° reduces eye exposure by a factor of 2. The calculation-based correction factor of 0.3 for wraparound type lead glasses was found to agree reasonably well with experimental data. Simple precautions, such as the positioning of the image screen away from the X-ray source, lead to a significant reduction of the eye lens dose. Measurements and simulations performed in this work also show that a general eye lens correction factor of 0.5 can be used when lead glasses are worn regardless of operator position, height and body orientation. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  15. X-Rays spectrum and air kerma during a mammography study;Espectro de los rayos X y kerma en aire durante un estudio mamografico

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez G, J. [Instituto Nacional de Estadistica Geografia e Informatica, Direccion General de Innovacion y Tecnologia de Informacion, Av. Heroes de Nacozari Sur No. 2301, Fracc. Jardines del Parque, 20276 Aguascalientes (Mexico); Hernandez V, R.; Chacon R, A.; Vega C, H. R., E-mail: ramirezgonzalezjaime@yahoo.com.m [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2009-10-15

    The X-rays spectrum produced in a mammography has been calculated by means of Monte Carlo methods. In this calculation series it is modeled the electrons source, the target and the filter. The spectra were calculated for an energy of the electrons of 28 keV and for targets of W, Mo and Rh. The calculations extended to analyze the effect that produces the filters inclusion in the spectra; the spectra of W-A1, Rh-Rh, Mo-Mo, Mo-Rh and Mo-Be were calculated this way. Using thermoluminescent dosemeters of ZrO{sub 2}+PTFE the air kerma was measured in five points located on a phantom made with acrylic and water when it is was exposed to a X-rays beam produced by electrons of 24 keV and 10 m A of current that it produces a mammography. The values of the air kerma on the entrance surface of the phantom were compared with the calculated values by means of Monte Carlo methods. The calculated spectra present a continuous component and another discreet and its form is similar to the reported spectra in the literature. The filters inclusion allows the elimination of the low energy photons that do not have utility in the obtaining of the mammography image and only they contribute to deposit a dose in the mamma. The values of the measured air kerma indicate that the five points receive the same air kerma approximately, what means that the beam is homogeneous, of the Monte Carlo calculations we find that the center receives a bigger dose which implies that the beam is not uniform, the explanation on this fact it is attributed to that a simple model was used in the calculations, nevertheless, the average of the air kerma measured on the entrance surface of the phantom was of 0.96 +- 0.03 m G, while the obtained by means of the calculations was of 0.96 +- 0.06 mGy, when comparing both significant differences do not exist. (Author)

  16. Study on the thermoluminescent properties of K{sub 2}YF{sub 5} and K{sub 2}GdF{sub 5} crystals doped with optically active trivalent ions for gamma and neutrons dosimetry; Estudo das propriedades termoluminescentes de cristais de K{sub 2}YF{sub 5} e K{sub 2}GdF{sub 5} dopados com ions trivalentes opticamente ativos para dosimetria gama e de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Edna Carla da

    2008-07-01

    In this work, the thermoluminescent (TL) properties of both double potassium yttrium fluoride (K{sub 2}YF{sub 5}) and double potassium gadolinium fluoride (K{sub 2}GdF{sub 5}) crystals doped with optically active rare earth ions were investigated from the point of view of gamma and neutron dosimetry. Crystalline platelets with thickness of about 1 mm, synthesized under hydrothermal conditions, were irradiated in order to study TL sensitivity, as well as dose and energy response, reproducibility and fading, in terms of Ce{sup 3+}, Tb{sup 3+}, Dy{sup 3+}, e Pr{sup 3+} concentrations. The K{sub 2}YF{sub 5} crystals doped with 1.0 at por cent Dy{sup 3+} have been found to have an excellent linear TL response to X and gamma photons, in the range of 0.01 to 10 mGy. The TL output is comparable to that of CaS0{sub 4}:Mn dosemeters. The main peak at 130 deg C has been found to have a TL response for 41.1 keV X-ray energy 32 times higher than that for 662 keV gamma rays. This fact points out that the K{sub 2}Y{sub 0.99}Dy{sub 0.01}F{sub 5} crystals have great potential for X-rays diagnostic and/or industrial radiography. On the other hand, the K{sub 2}GdF{sub 5} crystals doped with 5.0 at por cent Dy{sup 3+} have been found to have the better TL response for gamma and fast neutron radiation, among the dopants studied. For gamma fields the TL response was linear for doses ranging from 0.1 to 200 mGy. The TL peak around 200 deg C can be deconvoluted into four individual peaks, all of them with linear behavior. For fast neutron radiation produced by an {sup 241}Am{sub B}e source, the TL responses for doses ranging from 0.6 to 12 mSv were also linear and comparable to that of commercial TLD-600, irradiated at same conditions. The TL emission due to neutrons was in the high temperature range, above 200 deg C. These results points out that K{sub 2}Gd{sub 0.95}Dy{sub 0.05}F{sub 5} crystals are good candidates for use in neutron dosimetry applications. (author)

  17. Skin dose measurements using radiochromic films, TLDS and ionisation chamber and comparison with Monte Carlo simulation.

    Science.gov (United States)

    Alashrah, Saleh; Kandaiya, Sivamany; Maalej, Nabil; El-Taher, A

    2014-12-01

    Estimation of the surface dose is very important for patients undergoing radiation therapy. The purpose of this study is to investigate the dose at the surface of a water phantom at a depth of 0.007 cm as recommended by the International Commission on Radiological Protection and International Commission on Radiation Units and Measurement with radiochromic films (RFs), thermoluminescent dosemeters and an ionisation chamber in a 6-MV photon beam. The results were compared with the theoretical calculation using Monte Carlo (MC) simulation software (MCNP5, BEAMnrc and DOSXYZnrc). The RF was calibrated by placing the films at a depth of maximum dose (d(max)) in a solid water phantom and exposing it to doses from 0 to 500 cGy. The films were scanned using a transmission high-resolution HP scanner. The optical density of the film was obtained from the red component of the RGB images using ImageJ software. The per cent surface dose (PSD) and percentage depth dose (PDD) curve were obtained by placing film pieces at the surface and at different depths in the solid water phantom. TLDs were placed at a depth of 10 cm in a solid water phantom for calibration. Then the TLDs were placed at different depths in the water phantom and were exposed to obtain the PDD. The obtained PSD and PDD values were compared with those obtained using a cylindrical ionisation chamber. The PSD was also determined using Monte Carlo simulation of a LINAC 6-MV photon beam. The extrapolation method was used to determine the PSD for all measurements. The PSD was 15.0±3.6% for RF. The TLD measurement of the PSD was 16.0±5.0%. The (0.6 cm(3)) cylindrical ionisation chamber measurement of the PSD was 50.0±3.0%. The theoretical calculation using MCNP5 and DOSXYZnrc yielded a PSD of 15.0±2.0% and 15.7±2.2%. In this study, good agreement between PSD measurements was observed using RF and TLDs with the Monte Carlo calculation. However, the cylindrical chamber measurement yielded an overestimate of the PSD

  18. Energy dependent response of plastic scintillation detectors to photon radiation of low to medium energy.

    Science.gov (United States)

    Ebenau, Melanie; Radeck, Désirée; Bambynek, Markus; Sommer, Holger; Flühs, Dirk; Spaan, Bernhard; Eichmann, Marion

    2016-08-01

    Plastic scintillation detectors are promising candidates for the dosimetry of low- to medium-energy photons but quantitative knowledge of their energy response is a prerequisite for their correct use. The purpose of this study was to characterize the energy dependent response of small scintillation detectors (active volume radiation qualities ranging from 10 to 280 kV and at a (60)Co beam. All calibrations were performed at the Physikalisch-Technische Bundesanstalt, the National Metrology Institute of Germany. The energy response in terms of air kerma, dose to water, and dose to the scintillator was determined. Conversion factors from air kerma to dose to water and to dose to the scintillator were derived from Monte Carlo simulations. In order to quantitatively describe the energy dependence, a semiempirical model known as unimolecular quenching or Birks' formula was fitted to the data and from this the response to secondary electrons generated within the scintillator material BC400 was derived. The detector energy response in terms of air kerma differs for different scintillator sizes and different detector casings. It is therefore necessary to take attenuation within the scintillator and in the casing into account when deriving the response in terms of dose to water from a calibration in terms of air kerma. The measured energy response in terms of dose to water for BC400 cannot be reproduced by the ratio of mean mass energy-absorption coefficients for polyvinyl toluene to water but shows evidence of quenching. The quenching parameter kB in Birks' formula was determined to be kB = (12.3 ± 0.9) mg MeV(-1) cm(-2). The energy response was quantified relative to the response to (60)Co which is the common radiation quality for the calibration of therapy dosemeters. The observed energy dependence could be well explained with the assumption of ionization quenching as described by Birks' formula. Plastic scintillation detectors should be calibrated at the same radiation

  19. Development of optically stimulated luminescence techniques using natural minerals and ceramics, and their application to retrospective dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Boetter-Jensen, L

    2000-09-01

    This thesis summarises research and development of optically stimulated luminescence (OSL) and its applications by the author at Risoe National Laboratory, up to 1999. These developments have been directed primarily at retrospective accident dosimetry and luminescence dating. Experimental investigations include the studies of OSL properties of the natural minerals quartz and feldspars and the artificial materials porcelain and aluminium oxide (Al{sub 2}O{sub 3}). Blue light emitting diodes and infrared laser diodes are shown to provide simple and practical alternatives to broad-band light and visible laser stimulation. The development of OSL apparatus designed for the rapid measurement of single grains of phosphors also opens up a new area of luminescence measurement, allowing the detailed examination of dose distributions within a multiple-grain sample. This is of particular importance to the studies of incompletely reset geological sediments, and to accident dosimetry measurements using unheated materials. Al{sub 2}O{sub 3}:C single crystals are tested as environmental OSL dosemeters for assessing both the natural background photon radiation dose rates in the field and the natural dose rates inside bricks collected for accident dose evaluation. Environmental doses of the order of few {mu}Gy are measured with high precision. UV photo-stimulated luminescence spectra obtained from porcelain samples are used to confirm that the main component responsible for the OSL signal from porcelain is Al{sub 2}O{sub 3}. OSL single-aliquot regenerative-dose (SAR) techniques are used with quartz extracted from Chernobyl bricks to determine the accrued dose after the accident. This has improved the measurement precision significantly, from about 5-6 % using traditional methods to now less than 2 %. Depth-dose profiles measured in Chernobyl bricks are compared with those obtained in the laboratory using different gamma sources and these comparisons show that the average energy of

  20. Effects of the material composition in the TL curves of alkaline halides with Eu{sup 2+} exposed to {beta} radiation; Efectos de la composicion del material en las curvas de TL de halogenuros alcalinos con Eu{sup 2+} expuestos a radiacion {beta}

    Energy Technology Data Exchange (ETDEWEB)

    Perez S, R.; Piters, T.; Aceves, R.; Rodriguez M, R. [Dpto. de Investigacion en Fisica, Universidad de Sonora, 83190 Hermosillo, Sonora (Mexico)

    2006-07-01

    The solid state dosemeters plays a very important paper in the growing use of the ionizing radiation. When being increased the use of the radioactive isotopes in the medicine and in the industry, the necessity to have materials but adapted in each case it has increased. To synthesize such materials, it is necessary to enlarge the knowledge on the paper that its play the physical characteristics of the crystals such as the crystalline structure, the lattice constant, imbibed nano structures, dislocations, ions size, electronic states of the ions, etc., on the effects of the ionizing radiation. In the past its have been carried out many studies approaching these problems in some materials, but we consider that its are insufficient before the challenges of the applications. To contribute to the understanding of these effects, we present a study focused to alkaline halide crystals impurified with Eu{sup 2+} ions, making an analysis on the paper that its play a) the ions concentration of Eu{sup 2+} in KBr: Eu{sup 2+}, b) the different sites of trapping of electrons and holes in KBr: Eu{sup 2+}, KCl: Eu{sup 2+}, RbBr:Eu{sup 2+}, RbCl: Eu{sup 2+} and c) the composition of the crystalline solid solutions KCl{sub x}Br{sub 1-X}: Eu{sup 2+} and RbCI{sub x}KBr{sub 1-x}: Eu{sup 2+} on the thermoluminescence curve when these materials are exposed to small dose of {beta} irradiation. The increase in the concentration of Eu{sup 2+} ions produces a smaller relative intensity of the emissions of high temperature for a given dose and it is found that in a RbCl{sub x}KBr{sub 1-x}: Eu{sup 2+} with the greater/smaller concentration of Cl{sup -} ions, the temperature of the characteristic emission is near to the 453/373 K. The composition x of halogenous ions and not the one of alkaline in the crystalline solid solution dominates the landslide of the temperature of the emission. (Author)

  1. Radioactive contamination in monitors received for calibration; Contaminacao em monitores de radiacao recebidos para calibracao

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Paulo S.; Santos, Gilvan C. dos; Brunelo, Maria Antonieta G.; Paula, Tiago C. de; Pires, Marina A.; Borges, Jose C. [MRA Comercio de Instrumentos Eletronicos Ltda., Jardinopolis, SP (Brazil). Centro de Ensaios e Pesquisas em Metrologia (METROBRAS)

    2013-10-01

    The Calibration Laboratory - LABCAL, from the Research Center for Metrology and Testing - METROBRAS, MRA Comercio de Instrumentos Eletronicos Ltda., began activities in October 2008 and, in August 2009, decided to establish a procedure for monitoring tests, external and internal, of all packages received from customers, containing instruments for calibration. The aim was to investigate possible contamination radioactive on these instruments. On July 2011, this procedure was extended to packagings of personal thermoluminescent dosemeters - TLD, received by the newly created Laboratory Laboratorio de Dosimetria Pessoal - LDP . In the monitoring procedure were used monitors with external probe, type pancake, MRA brand, models GP - 500 and MIR 7028. During the 37 months in which this investigation was conducted, were detected 42 cases of radioactive contamination, with the following characteristics: 1) just one case was personal dosimeter, TLD type; 2) just one case was not from a packing from nuclear medicine service - was from a mining company; 3) contamination occurred on packs and instruments, located and/or widespread; 4) contamination values ranged from slightly above the level of background radiation to about a thousand fold. Although METROBRAS has facilities for decontamination, in most cases, especially those of higher contamination, the procedure followed was to store the contaminated material in a room used for storage of radioactive sources. Periodically, each package and/or instrument was monitored, being released when the radiation level matched the background radiation. Every contamination detected, the client and/or owner of the instrument was informed. The Brazilian National Energy Commission - CNEN, was informed, during your public consultation for reviewing the standard for nuclear medicine services, held in mid-2012, having received from METROBRAS the statistical data available at the time. The high frequency of contamination detected and the high

  2. Radiation Protection Studies for Medical Particle Accelerators using Fluka Monte Carlo Code.

    Science.gov (United States)

    Infantino, Angelo; Cicoria, Gianfranco; Lucconi, Giulia; Pancaldi, Davide; Vichi, Sara; Zagni, Federico; Mostacci, Domiziano; Marengo, Mario

    2017-04-01

    Radiation protection (RP) in the use of medical cyclotrons involves many aspects both in the routine use and for the decommissioning of a site. Guidelines for site planning and installation, as well as for RP assessment, are given in international documents; however, the latter typically offer analytic methods of calculation of shielding and materials activation, in approximate or idealised geometry set-ups. The availability of Monte Carlo (MC) codes with accurate up-to-date libraries for transport and interaction of neutrons and charged particles at energies below 250 MeV, together with the continuously increasing power of modern computers, makes the systematic use of simulations with realistic geometries possible, yielding equipment and site-specific evaluation of the source terms, shielding requirements and all quantities relevant to RP at the same time. In this work, the well-known FLUKA MC code was used to simulate different aspects of RP in the use of biomedical accelerators, particularly for the production of medical radioisotopes. In the context of the Young Professionals Award, held at the IRPA 14 conference, only a part of the complete work is presented. In particular, the simulation of the GE PETtrace cyclotron (16.5 MeV) installed at S. Orsola-Malpighi University Hospital evaluated the effective dose distribution around the equipment; the effective number of neutrons produced per incident proton and their spectral distribution; the activation of the structure of the cyclotron and the vault walls; the activation of the ambient air, in particular the production of 41Ar. The simulations were validated, in terms of physical and transport parameters to be used at the energy range of interest, through an extensive measurement campaign of the neutron environmental dose equivalent using a rem-counter and TLD dosemeters. The validated model was then used in the design and the licensing request of a new Positron Emission Tomography facility. © The Author 2016

  3. Overview of the atmospheric ionizing radiation environment monitoring by Bulgarian build instruments

    Science.gov (United States)

    Dachev, Tsvetan; Tomov, Borislav; Matviichuk, Yury; Dimitrov, Plamen; Spurny, Frantisek; Ploc, Ondrej; Uchihori, Yukio; Flueckiger, Erwin; Kudela, Karel; Benton, Eric

    2012-10-01

    Humans are exposed to ionizing radiation all the time, and it is known that it can induce a variety of harmful biological effects. Consequently, it is necessary to quantitatively assess the level of exposure to this radiation as the basis for estimating risks for their health. Spacecraft and aircraft crews are exposed to elevated levels of cosmic radiation of galactic and solar origin and to secondary radiation produced in the atmosphere, the vehicle structure and its contents. The aircraft crew monitoring is required by the following recommendations of the International Commission on Radiological Protection (ICRP) (ICRP 1990), the European Union (EU) introduced a revised Basic Safety Standards Directive (EC 1997) which, inter alia, included the exposure to cosmic radiation. This approach has been also adopted in other official documents (NCRP 2002). In this overview we present the results of ground based, mountain peaks, aircraft, balloon and rocket radiation environment monitoring by means of a Si-diode energy deposition spectrometer Liulin type developed first in Bulgarian Academy of Sciences (BAS) for the purposes of the space radiation monitoring at MIR and International Space Station (ISS). These spectrometers-dosemeters are further developed, calibrated and used by scientific groups in different countries. Calibration procedures of them are performed at different accelerators including runs in the CERN high-energy reference field, simulating the radiation field at 10 km altitude in the atmosphere and with heavy ions in Chiba, Japan HIMAC accelerator were performed also. The long term aircraft data base were accumulated using specially developed battery operated instrument in 2001-2009 years onboard of A310-300 aircrafts of Czech Air Lines, during 24 about 2 months runs with more than 2000 flights and 13500 flight hours on routes over the Atlantic Ocean mainly. The obtained experimental data are compared with computational models like CARI and EPCARD. The

  4. Neutron fluence in a 18 MeV Electron Accelerator for Therapy; Fluencia de neutrones en un Acelerador de Electrones de 18 MeV para terapia

    Energy Technology Data Exchange (ETDEWEB)

    Paredes G, L.C. [Instituto Nacional de Investigaciones Nucleares, Direccion de Innovacion Tecnologica, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2001-07-01

    An investigation was made on the theoretical fundamentals for the determination of the neutron fluence in a linear electron accelerator for radiotherapy applications and the limit values of leakage neutron radiation established by guidelines and standards in radiation protection for these type of accelerators. This investigation includes the following parts: a) Exhaustive bibliographical review on the topics mentioned above, in order to combine and to update the necessary basic information to facilitate the understanding of this subject; b) Analysis of the accelerator operation and identification of its main components, specially in the accelerator head; c) Study of different types of targets and its materials for the Bremsstrahlung production which is based on the electron initial energy, the thickness of the target, and its angular distribution and energy, which influences in the neutron generation by means of the photonuclear and electro disintegration reactions; d) Analysis of the neutron yield based on the target type and its thickness, the energy of electrons and photons; e) Analysis of the neutron energy spectra generated in the accelerator head, inside and outside the treatment room; f) Study of the dosimetry fundamentals for neutron and photon mixed fields, the dosimeter selection criteria and standards applied for these applications, specially the Panasonic U D-809 thermoluminescent dosemeter and C R-39 nuclear track dosimeter; g) Theoretical calculation of the neutron yield using a simplified geometric model for the accelerator head with spherical cell, which considers the target, primary collimator, flattener filter, movable collimators and the head shielding as the main components for radiation production. The cases with W and Pb shielding for closed movable collimators and an irradiation field of 20 x 20 cm{sup 2} were analyzed and, h) Experimental evaluation of the leakage neutron radiation from the patient and head planes, observing that the

  5. Evaluation of absorbed dose and image quality in mammography

    Energy Technology Data Exchange (ETDEWEB)

    Hemdal, Bengt

    2009-07-01

    the dosemeters did not disturb the reading of the mammograms. A Monte Carlo study showed that the energy dependence could be reduced, primarily by reducing the diameter of the crystal. It is proposed that radiation scattered forward towards the breast from the compression paddle, a scanning device etc, should be considered with greater clarity in the breast dosimetry protocols, and be described with a forward-scatter factor, FSF, for the various geometries and conditions proposed. Low contrast-detail (CD) phantoms of simulated glandularity 30, 50 or 70%, and thickness 3, 5 or 7 cm, were used to compare three different mammography systems. The same number of perceivable objects was visible for the full-field DM system at 20-60% of the AGD necessary for the screen-film (SFM) system, with the largest dose reduction potential for the thickest phantoms with the highest glandularity. However, more recent research shows that CD phantoms with a homogeneous background, as used here, must be used with care due to the presence of 'anatomical noise' in the real clinical situation. Image quality criteria (IQC) recommended in a European Guideline 1996 for SFM were adjusted to be relevant also for DM images. The new set of IQC was tested in two different studies using clinical images from DM and SFM, respectively. The results indicate that the new set of IQC has a higher discriminative power than the old set. The results also suggest that AGD for the DM system used may be reduced

  6. Absorbed doses received by patients submitted to chest radiographs in hospitals of the city of Sao Paulo, Brazil; Doses absorvidas pelos pacientes submetidos a radiografias toracicas em hospitais do municipio de Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Marcelo Baptista de

    2000-07-01

    Medical irradiation contributes with a significant amount to the dose received by the population. Here, this contribution was evaluated in a survey of absorbed doses received by patients submitted to chest radiological examinations (postero-anterior (PA) and lateral (LAT) projections) in hospitals of the city of Sao Paulo. Due to the variety of equipment and procedures used in radiological examinations, a selection of hospitals was made (12, totalizing 27 X-ray facilities), taking into account their representativeness as medical institutions in the city, in terms of characteristics and number of radiographs carried out. An anthropomorphic phantom, provided with thermoluminescent dosemeters (TLD-1 00), was irradiated simulating the patient, and the radiographic image quality was evaluated. Absorbed doses were determined to the thoracic region (entrance and exit skin and lung doses), and to some important organs from the radiation protection point of view (lens of the eye, thyroid and gonads). The great variation on the exposure parameters (kV, mA.s, beam size) leads to a large interval of entrance skin doses-ESD (coefficients of variation, CV, of 60% and 76%, for PA and LAT projections, respectively, were found) and of organ doses (CV of 60% and 46%. for thyroid and lung respectively). Mean values of ESD for LAT and PA projections were 0.22 and 0.98 mGy, respectively. The average absorbed doses per exam (PA and LAT) to thyroid and lung, 0.15 and 0.24 mGy respectively,showed that the thyroid was irradiated by the primary beam in many cases. Values of lens of the eye and gonad absorbed doses were below 30 {mu}Gy. Comparison of the lung doses obtained in this study with values in the literature, calculated by Monte Carlo simulation, showed good agreement. On the other hand, the comparison shows significant differences in the dose values to organs outside the chest region (thyroid, lens of eye and gonads). The effective dose calculated for a chest examination, PA and

  7. Biological dosimetry of patients with differenced carcinoma of thyroid treated with Iodine-131; Dosimetria biologica de pacientes con carcinoma diferenciado de tiroides tratados con Iodo-131

    Energy Technology Data Exchange (ETDEWEB)

    Vallerga, M. B.; Rojo, A.M.; Taja, M.R.; Deluca, G.; Di Giorgio, M. [Autoridad Regulatoria Nuclear Av. Del Libertador 8250 (C1429BNP). Buenos Aires (Argentina); Fadel, A. [Hospital General de Agudos Dr. Carlos Durand Av. Diaz Velez 5044. Buenos Aires (Argentina); Cabrejas, M.; Valdivieso, C. [Hospital de Clfnicas Jose de San Martin Av. Cordoba 2351 (CP1120). Buenos Aires (Argentina)]. e-mail: mvallerg@cae.arn.gov.ar

    2006-07-01

    aberrations it was considered absorbed dose to whole body. The obtained doses were compared by the different biological methods used. The evaluation by internal dosimetry of the data obtained tracer post-activity allowed to personalize the activity of I-131 to administer, starting from physical-mathematical models that consider the particular biokinetics of each patient (MIRD methodology). The doses estimated by the used biological dosemeters were consistent among them. It was discussed its scopes and limitations to be applied in the validation of the dosimetric estimation based on models, in order to administer a therapeutic dose protecting the patient of the adverse effects of the internal radiotherapy in organs that are not target of the same one. The acquired experience is considered of utility to give answer in cases of radioiodine incorporation in occupationally exposed personnel. (Author)

  8. Contribution to the planning and dosimetry of photon beams applied to radiosurgery and stereotactic radiotherapy; Contribuicao ao planejamento e a dosimetria de feixes de fotons aplicados a radiocirurgia e a radioterapia estereotaxica

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Walter Menezes

    2003-08-15

    Radiosurgery and stereotactic radiotherapy are irradiation techniques that use small diameter photon beams for treating intracranial lesions such as pituitary adenomas, acoustic tumors and arterio-venous malformations which are inaccessible for surgery. These treatment techniques are characterized by the use of very small radiation beams which deliver a precisely measured dose to the target volume, while sparing the surrounding healthy tissue. Treatment can be performed by using multiple {sup 60}Co gamma-ray sources (in the so-called 'Gamma Knife'), charged particles or X-ray beams produced by linear accelerators. The prescribed dose can be given in a single session or in multiple fractions, as in conventional radiotherapy. The success of the treatment depends, among other factors, of the accurate determination of the parameters that characterize the radiation beam produced by the equipment, as well as, of a well designed quality assurance program. In this study, the dosimetric parameters of a set of collimating cones of a Radionics{sup TM} treatment system applied to two 6 MV- photon beams (Clinac 600C - Varian{sup TM}, and Mevatron MD2 - Siemens{sup TM}) were evaluated by using a water filled PMMA simulator. Measurements were carried out for photon beam diameters ranging from 12.5 to 40.0 mm for the Clinac-600C and from 5.0 to 50.0 mm for the Mevatron MD2. The parameters were evaluated by using a parallel plate ionization chamber (Markus), Kodak X-Omat V dosimetric films, thermoluminescent dosemeters (Harschaw, TLD-100) and photodiodes. The maximum tissue-ratio, the off-axis profile and the output factors were determined and the results were compared to those reported elsewhere. A study of the dosimetric characteristics of some commercially available phototransistors was also carried out. The results showed that these electronic components can be successfully used for measuring the dosimetric parameters of small diameter photon beans used in

  9. Determination of the radon concentration in soil and ground water and its association with the seismicity; Determinacion de la concentracion del radon en suelo y agua subterranea y su asociacion con la sismicidad

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Segovia, N. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Azorin, J. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    The coast of the Mexican Pacific is one of the seismic areas more active of the world due to the subduction of the badges of Coconuts and Rivera under the badge of North America. The earthquakes that happen in this part of Mexico they are of great magnitude and they affect to the central plateau of the country where finds the biggest population density. On the other hand the coast of the Gulf of Mexico presents one relatively low seismic activity. It is in this region where it is the nuclear plant of Laguna Verde (PNLV) and the studies of seismicity of the area should be carried out for questions of nuclear security. One carries out a study of fluctuations of the concentration of the radon in floor and it dilutes underground in the mentioned areas using accustomed to detectors of nuclear appearances (LR-115). Possibly they were also used detecting automatic (Clipperton sounds out). In some cases it was analysed the gamma radiation in soil using thermoluminescent dosemeters (CaSO{sub 4}: Dy + Ptfe). The mineralogical composition of rock samples was obtained, by means of technical conventional and Electron scanning microscopy and an X-ray diffractometer. The study one carries out along the coast of Guerrero, from Guacamayas, Mich. until Marquelia, Gro., of 1993 at 1998 and in the coast of the Gulf of Mexico, in the PNLV and their surroundings, of 1994 at 1996. The fluctuations of the radon concentration and of the gamma radiation, were analysed in function of the local seismic activity, the meteorological parameters and those characteristic geologic. In the area of the PNLV, the results showed that in general the averages of those value of the radon concentration, as much in floor as in water, they were low. A station located in a flaw area (New Ranch) the one that I present the values was but high of radon concentration, corresponding those but first floor to the PNLV. The seismic activity during the one period of sampling was sporadic and of low intensity and alone

  10. Scientific days on electromagnetic fields: from dosimetry to human health - Conference proceedings; Journees scientifiques - Champs electromagnetiques: de la dosimetrie a la sante humaine - Recueil des resumes et presentations

    Energy Technology Data Exchange (ETDEWEB)

    Wiart, J.; Ghanmi, A.; Picon, O.; Conil, E.; Varsier, N.; Hadjem, A.; Sudret, B.; Magne, I.; Souques, M.; Gaudaire, F.; De Seze, R.; Jawad, O.; Lautru, D.; Dricot, J.M.; Horlin, F.; De Doncker, P.; Drissaoui, A.; Musy, F.; Nicolas, L.; Perrussel, R.; Scorretti, R.; Voyer, D.; Jala, M.; Moulines, E.; Levy-Leduc, C.; Mahfouz, Z.; Gati, A.; Fouad Hanna, V.; Leveque, P.; Arnaud-Cormos, D.; Zhadobov, M.; Jarrige, P.; Gaborit, G.; Kohler, S.; Ticaud, N.; Duvillaret, L.; Guelilia, Z.; Loison, R.; Gillard, R.; Laisne, A.; Favet, D.; Benadhira, R.; Mir, L.; Nadi, M.; Kourtiche, D.; Gazeau, F.; Wilhelm, C.; Delemotte, L.; Breton, M.; Tarek, M.; Marc-Vergnes, J.P.; Yardin, C.; Perrin, A.; Le Drean, Y.; Sauleau, R.; Lambrozo, J.; Selmaoui, B.; Ghosn, R.; Thuroczy, G.; Villegier, A.S.; Loos, N.; Brenet-Dufour, V.; Liabeuf, S.; Bach, V.; Moretti, D.; Lewis, N.; Garenne, A.; Poulletier De Gannes, F.; Haro, E.; Lagroye, I.; Bornat, Y.; Boutaib, Y.; Saighi, S.; Renaud, S.; Veyre, B.; Schuz, J.; Deltour, I.; Van Deventer, E.; Vecchia, P.; Merckel, O.; Bellaouel, A.; Demaret, P.; Donati, P.; Jovanovic, D.; Chauvin, S.; Desreumaux, J.P.; Fouquet, L.; Picard, D.; Massardier-Pilonchery, A.; Hours, M.; Bergeret, A.; Person, C.; Toutain, Y.; Butet, R.; Berrahma, K.; Balderelli, I.; Stelmaszyk, V.; Cretallaz, C.; Lamproglou, I.; Amourette, C.; Diserbo, M.; Fauquette, W.; Martigne, P.; Collin, A.; Lagroye, I.; Ait Aissa, S.; Hurtier, A.; Taxile, M.; Le Montagner, L.; Athane, A.; Duleu, S.; Percherancier, Y.; Geffard, M.; Ruffie, G.; Billaudel, B.; Veyret, B.; Pelletier, A.; Delanaud, S.; Libert, J.P.; Schunck, T.; Bieth, F.; Soubere Mahamoud, Y.; Le Quement, C.; Ferrand, G.; Le Guevel, R.; Carton, P.H.; Luong, M.; Tanvir, S.; Selmaoui, B.; Silva Pires-Antonietti, V.; Sonnet, P.; Pulvin, S.; Kuster, O.; Tetelin, C.

    2012-04-15

    - Electromagnetic interferences and cardiac implants; 24 - RF effects on central nervous system: sleep, cognition, Electro-encephalography, vascularisation; 25 - Specific effects of an exposure to mobile phone RF waves on the autonomous nervous control of the cutaneous vasomotor tone; 26 - The ERNAM project: exposure of neuronal networks to the GSM-1800 signal; 27 - Mobile phones, power lines and cancer: the epidemiological evidence leading to classification as possible carcinogens; 28 - EMF Risk Assessment and Management: A WHO Perspective; 29 - Evolution of ICNIRP guidelines; 30 - Assessment of RF-linked risks at the Anses: from dialogue management recommendations; 31 - Characterization of mobile phone-absorbing medium interactions for non-invasive dosimetry; 32 - Status of electromagnetic radiation exposures and evaluation of prevention means; 33 - General public exposure to RF in France; 34 - Power emitted by a mobile phone in voice communication: from 2G to 3G VoIP; 35 - Digital dosimetry in HF/VHF range; 36 - Professional exposure of mobile phone maintenance technicians; 37 - Robot-less multi-sensors dosimetry for real time SAR measurement; 38 - High performance SAR meter for the characterization of 3G mobile phones exposure; 39 - RF dosemeters and user's body diffraction; 40 - RF waves and health: summary of 2007-2011 scientific publications; 41 - Behaviour of adult male wistar rats during high power pulsed electromagnetic waves (3 GHz); 42 - Wi-Fi effects: results of IMS Lab studies; 43 - Effects on the energy fluxes of young rats homeostasis during a chronic exposure to RF fields; 44 - Biological effects of very-high power and ultra-large range radiations: ISL's research programme; 45 - Study of cell-scale biological effects of pulsed RF fields used in high-resolution NMR-imaging; 46 - Effects of cell phone radiofrequency exposure on the human cytochrome P450 reductase; 47 - CEA's 'electromagnetic safety' working group; 48 - In situ evaluation of

  11. Control letters and uncertainties of the kerma patterns in air, dose absorbed in water and dose absorbed in air of the LSCD; Cartas de control e incertidumbres de los patrones de kerma en aire, dosis absorbida en agua y dosis absorbida en aire del LSCD

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, M.T.; Tovar M, V.M.; Cejudo A, J. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2005-12-15

    determinations of the temperature to diminish their influence in the U. c. The percentage difference of the magnitudes dosemeters carried out by it patterns are consistent with U certain. However, it is necessary to diminish the uncertainty in the physical factors different to {kappa}{sub {tau}} and {sigma}{sub {beta}} for the one case of the primary patterns; because these they should be those of smaller value of U. d. In the case of the secondary patterns and tertiary for the realization of the{kappa}{sub {alpha}}{sub {center_dot}} is necessary to determine the corrections explicitly for recombination and polarization; and to analyze their contribution in the U. e. It is necessary to recover the tracking for the mensurations of the humidity. f. It is recommended to continue the control mensurations for each pattern, taking it{sup s} the least a measure every fifteen days, that it corresponds at two measured for month and 24 at the year. g. The operation of the air conditioned perturb the measurement for such as it recommends not to use it, and alone to leave in balance the chamber with the air of the engine room. (Author)

  12. Optimización Interdisciplinaria de Protocolos en Tomografía Computada a partir de la modificación del mA y del control del ruido en la imagen Interdisciplinary optimization of CT Protocols by modificating mAand controlling image noise

    Directory of Open Access Journals (Sweden)

    D. Andisco

    2010-12-01

    Full Text Available Objetivo: A partir de la determinación de las dosis en los protocolos habitualmente utilizados en estudios de tomografía computada en una institución, se modificaron la menor cantidad de parámetros radiológicos posibles para bajar las dosis impartidas, sin perder la calidad de la imagen. Materiales y métodos: Para la determinación de las dosis en un tomógrafo General Electric Hi Speed - 120kV Helicoidal, se realizaron mediciones utilizando una cámara de ionización tipo lápiz, un dosímetro, fantomas craneal y abdominal de PMMAde 16 cm y 32 cm de diámetro respectivamente, y un fantoma de agua. Con estos elementos se midieron las dosis habitualmente utilizadas y el ruido correspondiente en cada uno de los estudios. Se trabajó con el grupo de técnicos ymédicos de la institución con el objetivo de disminuir la dosis de cada uno de los protocolos utilizados, manteniendo imágenes con calidad diagnóstica. Resultados: Si bien las dosis de los protocolos utilizados por la institución antes de realizado este estudio se encontraban dentro de los rangos reconocidos internacionalmente, se establecieron nuevos protocolos y se pudieron reducir las dosis entre un 20% a un 30%, sin perder calidad ni presentar inconvenientes para el diagnóstico al grupo médico que trabaja en la institución. Conclusiones: Es fundamental realizar actividades de optimización de protocolos en tomografía computada con el objetivo de disminuir la dosis que reciben los pacientes, modificando apropiadamente los parámetros de los protocolos sin perder calidad diagnóstica ni afectar la actividad médica. Esta tarea debe llevarse a cabo en forma interdisciplinaria.Purpose: To determine the dose frequently used in computed tomography and to modify radiological parameters in order to optimize each protocol according to the dose administered. Materials and Methods: To determine the dose, measurements were made using a pencil ionization chamber, a dosemeter, a 16 cm

  13. Neutron-photon mixed field dosimetry by TLD-700 glow curve analysis and its implementation in dose monitoring for Boron Neutron Capture Therapy (BNCT) treatments

    Energy Technology Data Exchange (ETDEWEB)

    Boggio, E. F.; Longhino, J. M. [Centro Atomico Bariloche, Departamento de Fisica de Reactores y Radiaciones / CNEA, Av. E. Bustillo Km 9.5, R8402AGP San Carlos de Bariloche (Argentina); Andres, P. A., E-mail: efboggio@cab.cnea.gov.ar [Centro Atomico Bariloche, Division Proteccion Radiologica / CNEA, Av. E. Bustillo Km 9.5, R8402AGP San Carlos de Bariloche (Argentina)

    2015-10-15

    BNCT is a cancerous cells selective, non-conventional radiotherapy modality to treat malignant tumors such as glioblastoma, melanoma and recurrent head and neck cancer. It consists of a two-step procedure: first, the patient is injected with a tumor localizing drug containing a non-radioactive isotope (Boron-10) with high slow neutron capture cross-section. In a second step, the patient is irradiated with neutrons, which are absorbed by the Boron-10 agent with the subsequently nuclear reaction B- 10(n,a)Li-7, thereby resulting in dose at cellular level due to the high-Let particles. The neutron fields suitable for BNCT are characterized by high neutron fluxes and low gamma dose. Determination of each component is not an easy task, especially when the volume of measurement is quite small or inaccessible for a miniature ionization chamber, for example. A method of measuring the photon and slow neutron dose(mainly by N-14 and B-10) from the glow curve (GC) analysis of a single {sup 7}LiF thermoluminescence detector is evaluated. This method was suggested by the group headed by Dr. Grazia Gambarini. The dosemeters used were TLD-600 ({sup 6}LiF:Mg,Ti with 95.6% {sup 6}Li) and TLD-700 ({sup 7}LiF:Mg,Ti with 99.9% {sup 7}LiF) from Harshaw. Photon dose measurement using the GC analysis method with TLD-700 in mixed fields requires the relation of the two main peaks of a TLD-600 GC shape obtained from an exposition to the same neutron field, and a photon calibrated GC with TLD-700. The requirements for slow neutron dose measurements are similar. In order to properly apply the GC analysis method at the Ra-6 Research Reactor BNCT facility, measurements were carried out in a standard water phantom, fully characterized on the BNCT beam by conventional techniques (activation detectors and paired ionization chambers technique). Next, the method was implemented in whole body dose monitoring of a patient undergoing a BNCT treatment, using a Bo MAb (Bottle Manikin Absorption) phantom

  14. Irradiation of members of the general public from radioactive caesium following the Chernobyl reactor accident. Field studies in a highly contaminated area in the Bryansk region, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Thornberg, C

    2000-11-01

    From 1990 to 1999, estimations of the effective dose from external as well as internal irradiation from {sup 137}Cs and {sup 134}Cs were carried out for inhabitants in rural villages in the Bryansk region, Russia, highly contaminated due to the Chernobyl accident in 1986. The villages were situated about 180 km from the Chernobyl power plant and the deposition of {sup 137}Cs was in the range 0.9-2.7 MBq/m{sup 2}. Yearly expeditions were conducted in autumn by members of the Departments of Radiation Physics in Malmoe and Goeteborg, Institute of Radiation Hygiene, St. Petersburg and the the first 5 years also by the Norwegian Radiation Protection Authority. The dose levels and their change in time were estimated for various groups of the general public. The body burden of {sup 134,137}Cs and hence, the effective dose, was estimated from measurements of the urinary concentration of cesium radionuclides, together with direct measurements of the body content using a portable detector. The effective dose from external irradiation was estimated from measurements with thermoluminescent dosemeters worn by the participants during one month each year. In a special case study, the changes in biokinetics of {sup 137}Cs during pregnancy was investigated in a woman with an unintended intake of {sup 137}Cs via mushrooms from a highly contaminated forest in the area. During pregnancy there is an increased excretion of cesium resulting in a biological half-time of cesium which was 54% of the half-time before pregnancy. The ratio of the {sup 137}Cs concentration in breast milk (Bq/l) to that in the mother's body (Bq/kg) was 15% one month after the child was born. The body burden of {sup 137}Cs in the Russian individuals calculated from the concentration of {sup 137}Cs in urine showed a good agreement with the body burden estimated from in vivo measurements in the same individuals. Normalisation of the cesium concentration in the urine samples by the use of potassium or

  15. Individual monitoring of external exposure in terms of personal dose equivalent, H{sub p}(d); Dosimetria personale esterna in termini di equivalente di dose personale, H{sub p}(d). Atti. Giornata di studio, Bologna, 28 febbraio 2001

    Energy Technology Data Exchange (ETDEWEB)

    Fantuzzi, E. [ENEA, Div. Protezione dell' Uomo e degli Ecosistemi, Centro Ricerche Ezio Clementel, Bologna (Italy)

    2001-07-01

    The institute for Radiation Protection of ENEA - Bologna has organised a one day-workshop on the subject: Individual monitoring of external exposure in terms of personal dose equivalent, H{sub p}(d). The aim of the workshop was the discussion of the new implications and modifications to be expected in the routine individual monitoring of external radiation, due to the issue of the Decree 241/00 (G.U. 31/8/2000) in charge since 01/01/2001. The decree set up in Italian law the standards contained in the European Directive EURATOM 96/29-Basic Standards for the Protection of Health of Workers and the General Public against Dangers arising from Ionizing Radiation. Among others, the definition of the operational quantities for external radiation for personal and environmental monitoring, H{sub p}(d) e H{sup *}(d) respectively as defined by ICRU (International Commission for Radiation Units and Measurements), requires to update the methods of measurements and calibration of the personal dosemeters and environmental monitors. This report collects the papers presented at the workshop dealing with the Personal Dose Equivalent, H{sub p}(d), the conversion coefficients, H{sub p}(d)/K{sub a} e H{sub p}(d)/{sub ,} obtained through Monte Carlo calculations published by ICRU and ICRP (International Commission for Radiation Protection), the new calibration procedures and the practical implication in the routine of individual monitoring in terms of H{sub p}(d). Eventually, in the last chapter, the answers to Frequently Asked Questions (FAQ) are briefly reported. [Italian] L'Istituto per la Radioprotezione dell'ENEA di Bologna ha organizzato una giornata di studio Dosimetria personale esterna in termini di equivalente di dose personale, H{sub p}(d). Lo scopo della giornata e' stato quello di discutere le novita' e le modifiche da apportare alle pratiche di monitoraggio dell'esposizione esterna alle radiazioni ionizzanti, a seguito dell'entrata in vigore

  16. 8. national congress of radiation protection 'SFRP 2011' - Proceedings; Huitieme congres national de radioprotection 'SFRP 2011' - Recueil des presentations

    Energy Technology Data Exchange (ETDEWEB)

    Souques, M.; Lambrozo, J.; Perrin, A.; Magne, I.; Bedja, M.; Fleury, G.; Le Brusquet, L.; Barbe, R.; Lahaye, T.; Laurier, D.; Tomasek, L.; Tirmarche, M.; Guseva Canu, I.; Garsi, J.P.; Caer-Lorho, S.; Jacob, S.; Acker, A.; Fernandez, F.; Bertho, J.M.; Synhaeve, N.; Stefani, J.; Desbree, A.; Blanchardon, E.; Dublineau, I.; Petitot, F.; Lestaevel, P.; Tourlonias, E.; Mazzucco, C.; Jacquinot, S.; Dhieux, B.; Delissen, O.; Tournier, B.; Gensdarmes, F.; Godet, J.L.; Perrin, M.L.; Saad, N.; Bardelay, C.; Voytchev, M.; Doursout, T.; Chapalain, E.; Dandrieux, G.; Cazala, C.; Gay, D.; Chabanis, O.; Palut-Laurent, O.; Ringeard, C.; Thomassin, A.; Roxin, A.M.; Gschwind, R.; Makovicka, L.; Roxin, I.; Henriet, J.; Martin, E.; Klopfenstein, J.F.; Lochard, J.; Guillaumont, R.; Marignac, Y.; Petitfrere, M.; Catelinois, O.; Devin, P.; Sene, M.; Barbey, P.; Reaud, C.; Schneider, T.; Achikian, S.; Le Clerc, A.; Rochereau, S.; Schneider, C.; Vigneron, H.; Charron, S.; Delattre, A.; Luccioni, C.; Monti, P.; Bernaud, J.Y.; Michielsen, N.; Bondiguel, S.; Bordy, J.M.; Daures, J.; Denoziere, M.; Gualdrini, G.; Mariotti, F.; Barre, A.; Beauval, A.; Davi, J.N.; Dupic, S.; Grincourt, D.; Kandil, A.; Marteel, C.; Vrammout, D.; Saintamon, F.; Aberkane, J.; Paquet, F.; Barbey, P.; Bardies, M.; Biau, A.; Blanchardon, E.; Chetioui, A.; Lebaron-Jacobs, L.; Pasquier, J.L.; Broggio, D.; Beurrier, J.; Farah, J.; Franck, D.; Sauget, M.; Bertrand, A.; Boveda, S.; Bar, O.; Brezin, A.; Maccia, C.; Bernier, M.O.; Struelens, L.; Carinou, E.; Dominiek, J.; Brodecki, M.; Donadille, L.; Ferrari, P.; Koukorava, C.; Krim, S.; Nikodemova, D.; Ruiz-Lopez, N.; Sans Merce, M.; Vanhavere, F.; Clairand, I.; Bordy, J.M.; Debroas, J.; Ginjaume, M.; Itie, C.; Krim, S.; Lebacq, A.L.; Martin, P.; Struelens, L.; Sans-Merce, M.; Vanhavere, F.; Gauron, C.; Wild, P.; Grzebyk, M.; Derock, C.; Champion, K.; Cohen, P.; Menez, C.; Tellart, A.S.; Thiel, H.; Pennarola, R.; Choudat, D.; Dillenseger, P.; Rehel, J.L. [and others

    2011-06-15

    -learning techniques in radiation protection and related domains; 22 - O'CLOC study - cataracts in interventional cardiologists; 23 - Doses received in extremities and eye lens by medical personnel: results of the ORAMED European project; 24 - Use of operational dosemeters in interventional radiology/cardiology: results of the ORAMED European project; 25 - Sub-ungual multi-parametric capillaroscopy of occupational chronic exposure in interventional radiology; 26 - Example of workplace and zoning analysis in interventional neuro-radiology; 27 - Dosimetric study of various work places in prostate brachytherapy; 28 - Contribution to radiation protection of the partial redesigning of a nuclear medicine service; 29 - Committed effective doses evaluated by the IRSN after internal contamination of nuclear medicine personnel - 2006-2010 status; 30 - Why and how developing a quality approach in radiation protection?; 31 - 2011 status and perspectives of radiation protection in medical environment. The ASN's viewpoint; 32 - Doses in scanography: results of a multi-centric inquiry; 33 - Status of the optimization approach of patients dosimetry in interventional radiology at Clermont Ferrand univ. health centre; 34 - Can we define reference levels in interventional neuro-radiology with diagnostic and therapeutic purposes?; 35 - EMAN: implementation of an ALARA european network in the medical domain; 36 - In-vivo surface and intra-cavitary dosimetry in patient's radiotherapy using multi-channel OSL/FO technique; 37 - Estimation of secondary cancers after robotized stereotactic radiotherapy of lung cancer; 38 - Medical-surgical management of an injured person after radio-contamination by plutonium or americium (Percy area); 39 - Industrial radiography incident at Flamanville nuclear site; 40 - Incorporated activity mapping using Monte-Carlo simulations in case of complex contaminations; 41 - IRSN's metrology teams preparedness for crisis; 42 - Alpha irradiation problem following

  17. Cosmic Radiation and Aircrew Exposure: Implementation of European Requirements in Civil Aviation, Dublin, 1-3 July 1998

    Science.gov (United States)

    Talbot, Lee

    1999-03-01

    -year period. Professor O'Sullivan said that the NRPB used TLDs for low and high LET radiations and PADC for neutrons. The investigation of dosemeter response was carried out using Monte Carlo codes. The active instruments used for measurements were the tissue equivalent proportional counter (TEPC) and a Bonnersphere spectrometer using eight spheres. The instrumentation used was calibrated in the CERN-CEC reference field. In summary, it was found that the shape of the neutron spectrum does not change with altitudes and that the maximum dose rate was found to be under the seats of the aircraft. Dr Lindbourg of the Swedish Radiation Protection Institute gave a short talk on the importance of using the TEPC for cosmic ray measurements, as it is the only means of reading directly absorbed dose to tissue and the radiation quality (in terms of lineal energy). Dr Schewe from PTB, Germany, gave the next talk on reference fields and calibration procedures. The speaker highlighted the difficulties in measuring radiation fields onboard aircraft, as the calibration fields used are often vastly different to the radiation field the instrumentation is being exposed to. The speaker said that this could lead to errors in the measurements in excess of 50%. One way around this is to use realistic reference fields, which produce similar particle compositions and particle fluences as those present in the cosmic radiation at aircraft altitudes. For this work the reference field facility in one of the secondary beams lines of the CERN Super Proton Synchrotron was used. In summary it was shown that the TEPC could be used as a reference instrument for evaluating ambient dose equivalent in aircraft. The next speaker was Dr Tommasino of the ANPA, Rome, who talked about in-flight measurement of radiation fields and doses. He stated that the problem of radiation dose assessment has been developed within the multinational research programmes of the Commission of the European Communities. The speaker talked