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Sample records for biological dosemeters

  1. The effect of radiation on bioluminescent bacteria: possible use of luminescent bacteria as a biological dosemeter

    International Nuclear Information System (INIS)

    The purpose of the study was to investigate the response of the bioluminescent Photobacterium phosphoreum to radiation, and the possible use of the bacteria as a biological radiation dosemeter, i.e. a water-equivalent biological system that will compare beams not merely on the basis of absorbed dose, but also have intrinsic RBE values for different radiation beams. Samples were irradiated by a 12 MeV electron beam at a dose rate of 3.0 Gy min-1, by 60Co gamma rays at 2.85 Gy min-1, and by 100 kVsub(p) x-rays at a dose rate of 2.13 Gy min-1. To study dose-rate dependence, the survival fraction was obtained for a 12 MeV electron beam at 0.50 and 12 Gy min-1 for 20.0 Gy. The survival fraction proved to be independent of dose rate in this range. The results presented in this work indicate that by using bioluminescent bacteria, RBE measurements can be markedly simplified and the results interpreted unequivocally. (U.K.)

  2. Passive neutron dosemeter design

    International Nuclear Information System (INIS)

    A passive neutron dosemeter was designed to be used in mixed radiation fields. The design was carried out using Monte Carlo method. The dosemeter model was a 25.4 cm-diameter polyethylene sphere with a thermoluminescent dosemeter, TLD600, located at the sphere center. This model was irradiated with 50 monoenergetic neutron sources with energies from 10-8 to 20 MeV. A 506.71 cm2-area disk was used to model the source term whose center was located at 100 cm from polyethylene sphere's center. The dosemeter response was compared with the responses of SNOOPY, Harwell 95/0075 and PNR-4. With these responses it was calculated the dosemeter responses for 252Cf, 252Cf/D2O and 239PuBe neutron sources. The passive dosemeter relative response has the same shape of SNOOPY, Harwell 95/0075 and PNR-4 dosemeters. Due to the type of thermal neutron detector used in the passive dosemeter the absolute response per unit fluence, is lower than the absolute response of SNOOPY, Harwell 95/0075 and PNR-4 dosemeters. However the passive dosemeter response in function of the average neutron energy of the 252Cf, 252Cf/D2O and 239PuBe neutron energy was more linear

  3. Acid dip for dosemeter

    International Nuclear Information System (INIS)

    Background signal in a PTFE based dosemeter caused by impurities in the PTFE and in the active component such as lithium fluoride is substantially reduced by treating the dosemeter with acid. The optimum treatment involves use of hydrofluoric acid at room temperature for approximately one minute, followed by thorough washing with methanol, and finally drying. This treatment is best applied after the original manufacture of the dosemeters. It may also be applied to existing dosemeters after they have been in use for some time. The treatment produces a permanent effect in reducing both the light induced signal and the non-light induced signal. The process may be applied to all types of dosemeter manufactured from PTFE or other plastics or resins which are able to resist brief exposure to acid. The treatment works particularly well with dosemeters based on PTFE and lithium fluoride. It is also applicable to dosemeters based on calcium sulphate, lithium borate and magnesium borate. Acids which may be used include hydrofluoric, hydrochloric, nitric, phosphoric and sulphuric. (author)

  4. Personal neutron diode dosemeter

    International Nuclear Information System (INIS)

    The control and management of neutron doses, received by workers in nuclear power or research facilities, requires a knowledge of cumulated dose equivalent or dose equivalent rate in real time. Individual dosemeters so far developed for this purpose are scarce and not very satisfactory. Passive dosemeters such as TLD systems based on the albedo effect, nuclear emulsions or solid track detectors, do not give sufficiently accurate measurements. Furthermore, the increase in the quality factor and the more restrictive new ICRP recommendations diminish the maximum admissible threshold making currently used systems obsolete. Other than bubble dosemeter systems, based on thermodynamic effects of a superheated gel, no simple electronic device is available at the present time. The development of diode based dosimetric gamma badges, having a size similar to that of credit cards, has stimulated us to design and develop a personal neutron dosemeter based on a double diode system. The results obtained are very encouraging and practical models should become available in the near future. (author)

  5. Calibration of farmer dosemeters

    International Nuclear Information System (INIS)

    The Farmer Dosemeters of Atomic Energy Medical Centre (AEMC) Jamshoro were calibrated in the Secondary Standard Dosimetry Laboratory (SSDL) at PINSTECH, using the NPL Secondary Standard Therapy level X-ray exposure meter. The results are presented in this report. (authors)

  6. Principle and use of dosemeters

    International Nuclear Information System (INIS)

    The institute of nuclear physics of Orsay is accepted by the Ministry of Labour to insure the surveillance of workers individual external exposure against the danger of ionizing radiations and to execute monitoring of radiation protection. The dosemeters studied in this report are the photographic film dosemeters ( for x rays, gamma rays and beta - rays), the trace detectors (fast neutrons) and the radio thermo luminescent dosemeters. For each type, the principle and how to use it are given. (N.C.)

  7. European intercomparison of diagnostic dosemeters: calibration of the reference dosemeters

    International Nuclear Information System (INIS)

    The paper describes both the organisational and technical steps taken in the calibration of the reference dosemeters used in the intercomparison of diagnostic dosemeters carried out in Europe in 1990. A brief account is given on the activities by the coordinating centres in the 19 countries and by the calibrating institution to establish the operational framework necessary for carrying out the calibration. The second part describes the calibration of the dosemeters against PTB's primary standards in terms of the equipment used and of the individual steps of measurement taken. An assessment of the uncertainties associated with the calibration is presented

  8. 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.

  9. Response of electret dosemeter to slow neutrons

    International Nuclear Information System (INIS)

    The response of the electret dosemeter to exposition of slow neutrons is studied. Different external coatings are used on the dosemeter (polyethylene, alminium, polyethylene + boron, aluminium + boron) and exposure curves (with and without water) are compared. (M.A.C.)

  10. Acceptance testing of photographic film dosemeters

    International Nuclear Information System (INIS)

    The reports describes a system for acceptance testing of photographic film dosemeters in customary use in personal dosimetry. The system comprises a test of some of the fundamental dosimetric properties of the film. The acceptance test will be performed in connection with the semi-annual purchases of dosemeter film to the National Institute of Radiation Hygiene. The test program comprises both constancy tests and absolute requirements. The latter refer mainly to ISO 1757 - Personal photographic dosemeters. 2 refs

  11. History of development of electronic personal dosemeters

    International Nuclear Information System (INIS)

    The nuclear and accelerator facilities are now increasingly used, especially high-energy accelerators for various purposes such as nuclear physics, medical science, and engineering research. It is very important to monitor the personal dose equivalent of workers in such facilities by using a real-time personal dosemeter. As real-time personal dosemeter, the silicon semiconductor detectors are world-widely used in nuclear and accelerator facilities. We have developed the real-time personal dosemeters using GM-tube and silicon semiconductor detector from about 40 years before. This report describes the history of development of electronic personal dosemeters using at atomic power plants in Japan. (author)

  12. A smart electronic personal dosemeter

    International Nuclear Information System (INIS)

    A compact, smart electronic personal dosemeter for X and gamma radiation in the range of 60 keV to 1.3 MeV has been developed using a silicon diode semiconductor detector. The dosemeter is based on Atmel's 89C2051 micro-controller. It gives a 70dB audio alarm, when the accumulated radiation dose exceeds a preset value. A serial 4K byte serial EEPROM in the dosemeter holds the identification details of the person. Using a built-in real time clock, the accumulated dose is also stored along with date and time every half an hour in the EEPROM to provide information of high dose levels if and when they occur. A serial communication interface RS232C, at 1200 baud, is provided for entering user ID and the alarm value into the EEPROM and also for downloading stored dose data to a PC. The accumulated dose is displayed on a 6-digit LCD display and the unit covers a range of 1μSv to 999999μSv. The details of the hardware and software implementation are discussed. (author)

  13. Colour dosemeters for high level radiation dosimetry

    DEFF Research Database (Denmark)

    Schönbacher, H.; Coninckx, F.; Miller, A.; Kruska, G.; Wulf, I.

    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 i...

  14. Electronic personal dosemeters - current position and trends

    International Nuclear Information System (INIS)

    The electronic personnel dosemeter has an arrangement of silicon photodiodes using two detectors of different sizes, connected in a simple circuit with single pre-amplifier and amplifier. An excellent relationship in energy and angle is obtained. The advantage of this dosemeter is the immediate availability of the dose information. (DG)

  15. Problems at the Development of personal Beta-particle dosemeters-Beta Particle dosemeters-

    International Nuclear Information System (INIS)

    Workplaces at which beta radiation might significantly contribute to the doses to the extremities are increasingly found in radiation therapy, radiation source production and nuclear plants. for the measurement of the individual beta-particle dose, personal dosemeters for fingers, arms and legs are needed. Intercomparison measurements organised from 1996 by the PTB have shown that some dosemeter types based on TLD are suitable for this purpose and can be used as legal dosemeters for both photon and beta radiation. Also, some electronic personal photon dosemeters are investigated in beta radiation fields. it turned out that a few types are also sensitive to beta radiation and measure the personal dose equivalent rate to the skin with a low energy dependence. Only their wearing position is by far not optimal foe extremity dosimetry because they are worn on the chest. Advantages and disadvantages are discussed. The characterisation of workplaces is carried out by measuring dose profiles using area dosemeters. Investigations performed with several commercial types of these dosemeters furnish information about the selection of the suitable measuring device and its correct practical use. the development of improved dosemeters has to towards smaller detectors and higher sensitivity. Personal dosemeters have to be robust and acceptable to the user, which generally is not achieved for beta extremity dosemeters. It is an additional problem that even such dosemeters cannot always be worn in the appropriate place. (Author)

  16. Dosemeters for centralized personnel monitoring in the GDR

    International Nuclear Information System (INIS)

    Dosemeters used in the German Democratic Republic for centralized personnel monitoring are described in case of normal operation and accidents at NPP. Such dosemeters are as follows: photographic film dosemeters for the measurement of X and gamma radiation, and also for a rough evaluation of beta radiation; thermoluminescent dosemeters for measuring emergency doses of X and gamma radiation; thermoluminescent dosemeters for measuring arm irradiation by beta, gamma and X radiation; activation dosemeters for neutron emergency dosimetry, and also some special dosemeters. Their design, measuring ranges and measurement error are briefly discussed

  17. New generation of ''legal'' dosemeters

    International Nuclear Information System (INIS)

    In the early 1980s research at the National Radiological Protection Board in the UK proved the feasibility of using solid state electronics in an entirely new dosimetry technology - capable of reaching right down into the low energy photon ranges, and able to detect beta radiation. In 1988 the NRPB undertook a joint venture with Siemens Plessey Controls to develop a marketable personal dosemeter meeting full Health and Safety Executive approval as a ''legal'' instrument. The Electronic Personal Dosemeter (EPD) was thus conceived, and will reach the pre-production stage early this year. The EPD makes use of state-of-the-art silicon integrated circuit technology, with a custom amplifier and microprocessor system. The liquid crystal display continuously shows the accumulated short-term penetrating dose in terms of the Hp (10) unit, and can also show superficial dose and dose rates. Because the EPD must be continuously powered, the custom lithium battery was commissioned to ensure a minimum service interval of 12 months. The EPD is the size and weight of a small pocket pager. Although dose data can be read directly from the EPD, a comprehensive data management system is needed to effect real-life use in industry. The EPD thus communicates by infra-red link to a reader unit which interfaces an IBM-compatible PC, allowing authorized personnel to read the dose memories and perform dose alarm threshold settings. (author)

  18. The development of an electronic dosemeter

    International Nuclear Information System (INIS)

    The National Radiological Protection Board (NRPB) and Siemens Plessey Controls Ltd are in the process of developing an electronic dosemeter suitable for use by an approved dosimetry service for classified workers. Pre-production dosemeters and readers have now been produced and trials in conjunction with the Health and Safety Executive will commence shortly with the aim of setting up an approved dosimetry service at NRPB based on the use of the dosemeter. The way it is proposed to organise the service will be discussed. (Author)

  19. 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)

  20. Study about the feasibility of using an electret dosemeter as a personal dosemeter

    International Nuclear Information System (INIS)

    A feasibility study of the electret dosemeters as a personnel dosemeter was carried out. Preliminary tests were applied, in order to assess the dosemeter response to radiation, linearity, stability, reproductibility, direcional dependence and energy dependence in energy range from 33 to 1250 KeV. In general the results are in agreement with the recommendations of the Commision of the European Communities (CEC) for the use of this device as a personnel dosemeter with the exception of the energy dependence and the stability at medium term. (Author)

  1. The need for comparison of diagnostic dosemeters

    International Nuclear Information System (INIS)

    One precondition for successfully implementing quality control in diagnostic radiology is that the measuring instruments used are of adequate quality. Among the measuring instruments used for quality control, dosemeters play a predominant role. Therefore it is essential to know the performance characteristics of a suitable dosemeter and to have information on the uncertainties and measurement errors found during acceptance testing. An outline will be given of the requirements on the accuracy of dosemeters. Such requirements have to address the task of the dosemeter and also take into account their technical feasibility. In order to gather information on the performance characteristics of field instruments, a programme for a European intercomparison has been developed which was carried out in 1988. The programme, together with its underlying ideas and its objectives, is presented in this paper. (author)

  2. Glass as a gamma ray dosemeter

    International Nuclear Information System (INIS)

    The advantages of glass as a γ-rays dosemeter are studied. Experiments have shown that ordinary microscope object glass can be used as a dosemeter, which dose range for linear response extends from about 104-106 rads. Heat treatment of the irradiated samples accelerates the initial fading of coloration and stabilizes the residual optical density. On the other side cooling of them retards the initial fading. (author)

  3. New dose quantities for personnel dosemeters

    International Nuclear Information System (INIS)

    In 1985, the Workshop External Dosimetry (AKD) of the German-Swiss 'Fachverband fuer Strahlenschutz' and the Physikalisch-Technische Bundesanstalt (PTB) organized an intercomparison experiment in order to find out whether commonly used personal dosemeters are able to indicate the new ICRU dose quantities (ICRU 39) Hs (0,07) and Hp(10) recommended for personal dosimetry. A total number of 30 representative dosimetry systems participated at the interlaboratory test. These systems make use mainly of L and RPL dosemeters, but also film dosemeters and direct reading dosemeters have been chosen. The irradiations have been performed over the energy range 25-662 keV using irradiations free in air as well as on the ICRU sphere phantom. Under an angle of 00, 450 and on the rotating phantom. The effect of phantom type has been investigated using the ICRU sphere and the Alderson human phantom. With respect to the ICRU quantities, three categories of personal dosemeters have been found dosemeter systems which simultaneously indicate the exposure X as well as H'(0,07) and H'(10) without any change of the evaluation technique or energy compensation filter, dosemeter systems which must be improved either in the evaluation procedure or by using additional detector readings, and dosemeter systems which must be changed in the energy compensation filters. In different papers the participants discuss their own results. Additional contributions of the seminar are presented, which discuss general subjects of introducing new dose quantities and other concepts of calibration quantities for external dosimetry. (orig./HP)

  4. Personnel monitoring of radiations with thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    The basics of personnel dosimetry technics, used by the Radiologic Protetion and Assessorie Service (SAPRA) are presented, consisting on use of thermoluminescent and CaSO4:Dy monitors in aggregated pellets by Teflon. The characteristics of this dosemeters, relating to the sensitivity, energetic dependence, spike temperature, characteristic emission curve, decay and light effect are shown. The thermoluminescent dosemeter measure system and the personnel monitoring system are also described. (C.G.C.)

  5. Self-indicating radiation alert dosemeter (SIRAD)

    International Nuclear Information System (INIS)

    In an event of a nuclear or dirty bomb explosion and a radiological accident, there is a need for self-indicating instant radiation dosemeter for monitoring radiation exposure. The self-indicating instant radiation alert dosemeter (SIRAD) is a credit card size radiation dosemeter for monitoring ionising radiation from a few hundredths of a Gray to a few Gray. It is always active and is ready to use. It needs no battery. The dosemeter develops colour instantly upon exposure, and the colour intensifies with dose. It has a colour chart so that the dose on the active element may be read by matching its colour with the chart that is printed next to it on the card. However, in this work, the dose is measured by the optical density of the element. The dosemeter cannot be reset. The response changes by 3 y at room temperature. It contains no hazardous materials. The dosemeter would meet the requirements of instantly monitoring high dose in an event of a nuclear or dirty bomb explosion or a radiation accident. (authors)

  6. Photodiode based dosemeter for patient dose monitoring

    International Nuclear Information System (INIS)

    This work describes the performance of a dosemeter, based on a photodiode device, compared to an ionization chamber for on-line dose monitoring applied to the patient during radiotherapy procedures. The dosemeter is constituted by two photodiodes, connected without polarisation to a digital current integrator. The dosemeter was tested in a water phantom and 60Co gamma ray. The depth dose distribution and the variation response with depth of the dosemeter were obtained. The results were compared to those obtained with a secondary standard, take as reference dosemeter. The response of this dosemeter had a deviation of 0,7 % from the ion chamber performance in water phantom measurement. The response variation with depth was less than 1 %. This is better than 8 % of diodes, determined by other authors. The developed device can substitute ion chambers in some routine absorbed dose to water measurements, with advantage of low cost and robust form. It has better performance than diodes, for given dose for patient. (author)

  7. Thermoluminescent lithium fluorides dosemeters in personnel monitoring in the GDR

    International Nuclear Information System (INIS)

    Described are thermoluminescent (TL) dosemeters of lithium fluoride used in centralized personnel monitoring in the GDR. Results of large-scale experiment are presented to compare the accuracy of readings of lithium fluoride or teflon dosemeter and that of film dosemeters. 332 persons were controlled for the experiment. A phantom was irradiated simultaneously by X and gamma radiation. The experience in application of thermoluminescent dosemeters to personnel monitoring of radiation load of a whole body and body parts using rings is described. Two Types of TL ring dosemeters for measuring X, gamma and deta radiations are presented. Advantage and shortcomings of TL dosemeters are noted

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

    DEFF Research Database (Denmark)

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

  9. Active neutron/photon personal dosemeters

    International Nuclear Information System (INIS)

    Though active personal dosemeters for photon fields reflect already a high level of development, there is still a need to advance the design of dosemeters for use in mixed neutron/photon fields and especially for monitoring the staff of nuclear power plants and the personnel accompanying transports of spent fuel flasks. The measurement of the neutron component is usually associated with problems. After a short description of the complex mixed fields in the nuclear fuel cycle, the commercially available active dosemeters and those under development will be listed and problems arising from their use in these fields will be discussed. Two new developments, the Siemens EPD-N2 and the PTB DOS-2002, which both are capable of indicating neutron and photon doses, will be described and discussed in detail. New response functions with respect to personal dose equivalent Hp(10) will be presented for neutrons. They have been determined by measurements in the quasi-monoenergetic reference fields at PTB in the energy range from 24 keV to 14.8 MeV and in fields with broad spectral distributions using the radionuclide sources 252Cf(bare), 252Cf(D2O,mod) - with and without cadmium shielding - 241Am-Be as well as a thermal neutron beam. The spectral distributions of all fields and the readings of the dosemeters in these fields were taken as inputs for an unfolding procedure to determine the dosemeter response in the overall energy region from thermal to 15 MeV. The procedure was tested by folding the dosemeter response with the broad neutron spectra and comparing with the readings of the dosemeters. Another problem in practical workplace fields is linked with high energy photons. Photons with energies from 6 MeV to 7 MeV from the 16O(n,pγ) reaction contribute to dose, particularly at reactors, and have to be taken into account when dosemeters are processed. Measurements with high energy photons were therefore performed with both devices and will be discussed. Finally, practical

  10. Angular and energetic dependence of photographic dosemeters for beta radiation

    International Nuclear Information System (INIS)

    Photographic dosemeters (Agfa-Gevaert) used in personal monitoring at IPEN/CNEN-SP (Brazil) are studied. The angular (between O and 1800) and energetic dependence in beta radiation exposures are discussed. The dosemeters are analysed with and without dosemeter - holder and retroscatter material. (M.A.C.)

  11. Colour dosemeters for high level radiation dosimetry

    DEFF Research Database (Denmark)

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

    1990-01-01

    interpretation or a dose measurement with a simple instrument such as a portable reflecting densitometer in the range of 10(3) to 10(6) Gy. Two projects were investigated: (1) a thin plastic film with a self adhesive tape containing a radiochromic dye which induces a colour change when exposed to ionising...... 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...

  12. Neutron dosimetry with TL albedo dosemeters at high energy accelerators

    International Nuclear Information System (INIS)

    The GSF-Personal Monitoring Service uses the TLD albedo dosemeter as standard neutron personal dosemeter. Due to its low sensitivity for fast neutrons however, it is generally not recommended for workplaces at high-energy accelerators. Test measurements with the albedo dosemeter were performed at the accelerator laboratories of GSI in Darmstadt and DESY in Hamburg to reconsider this hypothesis. It revealed that the albedo dosemeter can also be used as personal dosemeter at these workplaces, because at all measurement locations a significant part of neutrons with lower energies could be found, which were produced by scattering at walls or the ground. (authors)

  13. Calibrations of pocket dosemeters using a comparison method

    International Nuclear Information System (INIS)

    This monograph is dedicated mainly to the calibration of pocket dosemeters. Various types of radiation sources used in hospitals and different radiation detectors with emphasis on ionization chambers are briefly presented. Calibration methods based on the use of a reference dosemeter were developed to calibrate all pocket dosemeters existing at the Radiation Physics and Metrology Laboratory. Some of these dosemeters were used in personnel dosimetry at hospitals. Moreover, a study was realized about factors that affect the measurements with pocket dosemeters in the long term, such as discharges due to cosmic radiation. A DBASE IV program was developed to store the information included in the hospital's registry

  14. Intercomparison of secondary standard dosemeters in Latin America

    International Nuclear Information System (INIS)

    The National Laboratory for Ionizing Radiation Metrology/IRD has promoted an intercomparison among secondary and tertiary dosemeters which have been used as national standards in Latin America. Thirteen therapy level and five protection level dosemeters were brought by representatives, of eight countries and were compared against two reference dosemeters brought by an IAEA staff member. As far as the stablished limits for discrepancies are concerned it was possible to detect that therapy level secondary standard dosemeters failed in 4 conditions when 46 were used; therapy tertiary dosemeters failed in 5 of the 15 test conditions and the protection level secondary dosemeters showed 4 discrepancies during the 21 test conditions. The exercise emphasized the importance of intercomparisons as part of a quality control programme to garantee the metrological quality and the coherency of standard dosemeters with international metrological system. (author)

  15. Requirements of dosemeters for radiation protection

    International Nuclear Information System (INIS)

    This paper is intended to be as a guide for users in choosing the most suitable radiation detecting instrument for a specific use. The dosimetric characteristics and characteristics related to conditions of use for a dosemeter shall be considered before a choice can be made. All given information are strictly based on recommendations of ISO 4071-1978(E). (author)

  16. Unbiased metal oxide semiconductor ionising radiation dosemeter

    International Nuclear Information System (INIS)

    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.)

  17. Automatic exploitation system for photographic dosemeters

    International Nuclear Information System (INIS)

    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.)

  18. Implementing new recommendations for calibrating personal dosemeters

    International Nuclear Information System (INIS)

    This paper analyses the differences between the calibration procedures for personal dosemeters recommended by ICRU 47 and ISO 4037-3. The tissue equivalence of the PMMA and the ISO water slab phantoms are analysed by means of the Penelope Monte Carlo code for monoenergetic and filtered X ray photon beams and compared with the results of two other independent codes. The influence of the calibration method is also verified experimentally, both on a thermoluminescence and an electronic personal dosemeter. Good consistency between both calibration procedures is shown provided that a correction factor for backscatter differences between the PMMA and the ICRU phantom is introduced. The Monte Carlo simulation is used to determine this correction to a greater accuracy. (author)

  19. Principle and use of dosemeters; Principe et utilisation des dosimetres

    Energy Technology Data Exchange (ETDEWEB)

    Genet, S.; Ribaud, I.

    1997-12-31

    The institute of nuclear physics of Orsay is accepted by the Ministry of Labour to insure the surveillance of workers individual external exposure against the danger of ionizing radiations and to execute monitoring of radiation protection. The dosemeters studied in this report are the photographic film dosemeters ( for x rays, gamma rays and beta {sup -} rays), the trace detectors (fast neutrons) and the radio thermo luminescent dosemeters. For each type, the principle and how to use it are given. (N.C.).

  20. Passive neutron dosemeter-spectrometer for high-energy accelerators

    International Nuclear Information System (INIS)

    A passive neutron dosemeter-spectrometer (PNDS) with fission fragments converters is described. The results obtained show that it is a convenient and reliable instrument for neutron dose equivalent measurement in the calibration performing and response investigations of personnel dosemeters in mixed radiation fields behind accelerator shielding. Because of the possibility of neutron spectrum estimation in a wide energy range PNDS using is promissing in the neutron radiation fields research and also as an accidental neutron dosemeter. 23 refs.; 10 figs.; 4 tabs

  1. Factors affecting polyamide prototypes design of Albedo dosemeters

    International Nuclear Information System (INIS)

    This work studies the most important factors which affect the response of albedo neutron dosemeters containing LiF TLDs with the aim to improve their sensitivity. It includes tests of thickness and shape of the polyamide moderator body prototypes, albedo window diameter and TLD position inside the moderator. Analyzing the results, an albedo neutron dosemeter prototype, B4C covered, was developed. The prototype has a response three times higher than the albedo dosemeter now in use in Brazil. (author)

  2. PTB experience with design qualification testing of radiation dosemeters

    International Nuclear Information System (INIS)

    Radiation dosemeters with ionization chamber, a scintillator or a counting tube, are accepted for official calibration if the specimen has been approved by the PTB. The significance of the nowadays applied procedure, combining design qualification testing with subsequent calibration, is explained by comparing the measured data of the response of a given type A dosemeter, as a function of energy, dating back from periods prior to the introduction of the legal calibration duty, up to the dosemeter's official approval in 1982. (DG)

  3. Two miniature electronic dosemeters Yperwatch - Gamcard

    International Nuclear Information System (INIS)

    Yperwatch and Gamcard were miniature electronic gamma personal dose and dose rate monitors. The Yperwatch is mounted in a wristwatch and the Gamcard in a case of the size of a standard credit card. The technology provides users with all the performance of a standard professional electronic dosemeter (integrated dose, dose rate, audible alarms, time in use). Yperwatch and Gamcard are based on well-proven electronic dosimetry technology, but with a greater ease of use. (author)

  4. Personal radiation monitoring with thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    The technique of personal dosimetry used by SAPRA (Servico de Assessoria e Protecao Radiologica S/C Ltda., Brazil) is presented. Thermoluminescent monitors and CaSO4: Dy are used in pastilles united by teflon. Characteristics of the dosemeters are briefly reported. The system of thermoluminescent measurement, designed and constructed by SAPRA, and the system of personal monitoring are described. (M.A.C.)

  5. An extremity (wrist) dosemeter based on the Landauer InLight whole body dosemeter

    International Nuclear Information System (INIS)

    A number of Landauer's clients use wrist badges to monitor extremity doses surrounding the hand. In the past, in France, we have supplied clients with standard issue InLight (registered) whole body dosemeters, enclosed within a soft plastic pouch. A strap was used to secure the dosemeter around the wrist. The standard algorithm for whole body dosimetry was used to determine the dose-equivalent (Hp(0.07)). Clients requested a smaller and more comfortable design. Therefore, a new design was proposed in which only the InLight case and slide are contained within a smaller plastic pouch. This design is substantially smaller than the previous wrist badge and gives the client greater comfort while allowing the badges themselves to be read out using the same readers and procedures as our standard whole body dosemeters. A neutron dosemeter can also be included in this badge. This paper gives an overview of the new design and reports on type testing of the proposed wrist badge on an ICRU pillar (wrist) phantom, in terms of the energy and angular response. It was found that, while the standard algorithm for the InLight dosemeters performed well for photons and was correctly identifying the quality of the radiation exposure (low or high energy photons, low or high energy beta particles), there was a significant under response for beta particle exposures. Minor modifications to the algorithm were adopted. Finally, the recalculated results using the modified algorithm are compared to the requirements of the international standard for extremity dosemeters (ISO 12794:2000). (author)

  6. EURADOS intercomparison 2012 for neutron dosemeters

    International Nuclear Information System (INIS)

    EURADOS, within the work performed by Working Group 2 - Harmonization of Individual Monitoring in Europe, has started a self-sustained programme of regular intercomparisons and has successfully executed three intercomparisons for whole body photon dosemeters (IC2008, IC2010, IC2012) and one intercomparison for extremity dosemeters for photon and beta fields (IC2009). In 2012, the EURADOS intercomparison IC2012n was launched for personal neutron dosemeters routinely used to measure personal dose equivalent, Hp(10), in individual monitoring. No systems under development were allowed to participate. IC2012n was carried out by a EURADOS nominated Organization Group (OG) consisting of: Marie- Anne Chevallier (IRSN, F), Rodolfo Cruz-Suarez (IAEA, UN-Vienna), Marlies Luszik-Bhadra (PTB, D), Sabine Mayer (PSI, CH), David J. Thomas (NPL, UK), Rick Tanner (PHE, UK), Filip Vanhavere (SCK-CEN, B) led by a Coordinator, Elena Fantuzzi (ENEA, I). 31 participants registered for the comparison, with 34 dosimetry systems. In total 816 dosemeters were irradiated in selected neutron fields on an ISO slab phantom. The irradiations were performed at 2 European accredited laboratories which are both National Primary Metrology Laboratories for ionizing radiation: NPL (National Physical Laboratory, UK) and PTB (Physikalisch-Technische Bundesanstalt, D). All irradiations were carried out according to the irradiation plan developed by the OG. The overall results show that most, although not all, dosimetric systems perform acceptably well (within a factor of 2) for irradiations with a bare radionuclide source (252Cf at 0 ), whilst more than half of the systems underestimate the reference value for irradiations from non-normal angles of incidence irradiations (252Cf at 45 ) or for simulated workplace fields (252Cf(D2O) or 252Cf source behind a shadow cone). The performance for 250 keV mono-energetic neutron irradiations varies mainly reflecting the detection principle on which the dosimetric

  7. EURADOS intercomparison 2012 for neutron dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Fantuzzi, E. [ENEA-Radiation Protection Institute, Bologna (Italy); Chevallier, M.A. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France); Cruz-Suarez, R. [International Atomic Energy Agency, Vienna (Austria); Luszik-Bhadra, M. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Mayer, S. [Paul Scherrer Institute (PSI), Villigen (Switzerland); Thomas, D.J. [National Physical Laboratory (NPL), Teddington (United Kingdom); Tanner, R. [Public Health England, Oxon (United Kingdom); Vanhavere, F. [SCK-CEN, Belgian Nuclear Research Centre, Mol (Belgium)

    2014-11-15

    EURADOS, within the work performed by Working Group 2 - Harmonization of Individual Monitoring in Europe, has started a self-sustained programme of regular intercomparisons and has successfully executed three intercomparisons for whole body photon dosemeters (IC2008, IC2010, IC2012) and one intercomparison for extremity dosemeters for photon and beta fields (IC2009). In 2012, the EURADOS intercomparison IC2012n was launched for personal neutron dosemeters routinely used to measure personal dose equivalent, Hp(10), in individual monitoring. No systems under development were allowed to participate. IC2012n was carried out by a EURADOS nominated Organization Group (OG) consisting of: Marie- Anne Chevallier (IRSN, F), Rodolfo Cruz-Suarez (IAEA, UN-Vienna), Marlies Luszik-Bhadra (PTB, D), Sabine Mayer (PSI, CH), David J. Thomas (NPL, UK), Rick Tanner (PHE, UK), Filip Vanhavere (SCK-CEN, B) led by a Coordinator, Elena Fantuzzi (ENEA, I). 31 participants registered for the comparison, with 34 dosimetry systems. In total 816 dosemeters were irradiated in selected neutron fields on an ISO slab phantom. The irradiations were performed at 2 European accredited laboratories which are both National Primary Metrology Laboratories for ionizing radiation: NPL (National Physical Laboratory, UK) and PTB (Physikalisch-Technische Bundesanstalt, D). All irradiations were carried out according to the irradiation plan developed by the OG. The overall results show that most, although not all, dosimetric systems perform acceptably well (within a factor of 2) for irradiations with a bare radionuclide source ({sup 252}Cf at 0 ), whilst more than half of the systems underestimate the reference value for irradiations from non-normal angles of incidence irradiations ({sup 252}Cf at 45 ) or for simulated workplace fields ({sup 252}Cf(D{sub 2}O) or {sup 252}Cf source behind a shadow cone). The performance for 250 keV mono-energetic neutron irradiations varies mainly reflecting the detection

  8. 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. PMID:23528326

  9. Comparison of main thermoluminescent properties of some TL dosemeters

    DEFF Research Database (Denmark)

    Prokic, M.; Bøtter-Jensen, L.

    Different types of TL dosemeters that are attractive for dosimetry practice were investigated and compared. The aim of this study was to evaluate the TL characteristics of different TL dosemeters using two basically different types of commercially available TL readers. The findings demonstrate that...

  10. The performance of the NRPB radon personal dosemeter

    International Nuclear Information System (INIS)

    The NRPB has developed a radon personal dosemeter for use in mines. The dosemeter is being introduced into operational service subject to approval by the appropriate authorities. The principle of operation of the dosemeter is established both experimentally and theoretically. The dosemeter acts as a radon diffusion chamber, excluding radon progeny and detritus, limiting access of moisture but allowing relatively free access of radon gas. The alpha particles from the decay of radon and its progeny are recorded in a piece of polyallyl diglycol carbonate (PADC). The net density of the electrochemically etched pits is proportional to the time integral of the radon gas concentration external to the dosemeter. Prior to its introduction, trials of the dosemeter have been carried out in various mines in the United Kingdom. These trials were in addition to laboratory investigations of the performance of the dosemeter under simulated miners' conditions. The performance of the dosemeter is reported in terms of its ability to measure the time integral of the radon gas concentration unaffected by the environmental condition. (author)

  11. Performance of the Harshaw DXT-RAD (TLD-100) dosemeter

    Energy Technology Data Exchange (ETDEWEB)

    Moor, D.M. [Defence Science and Technology Laboratory, Environmental Sciences Department, Alverstoke, Gosport, Hants PO12 2DL (United Kingdom)], E-mail: dmoor@dstl.gov.uk; Horspool, B.; Stokes, R.P. [Defence Science and Technology Laboratory, Environmental Sciences Department, Alverstoke, Gosport, Hants PO12 2DL (United Kingdom)

    2008-02-15

    The Defence Science and Technology Laboratory (Dstl) has type-tested the Harshaw DXT-RAD dosemeter against the International Standard ISO 12794:2000(E) 'Individual thermoluminescence dosemeters for extremities and eyes' [International Organization for Standardization, 2000. International Standard ISO 12794:2000(E). Nuclear energy-radiation protection-individual thermoluminescence dosemeters for extremities and eyes]. The tests carried out included batch homogeneity, reproducibility, linearity, detection threshold, environmental stability (temperature, humidity and light), self irradiation, isotropy, energy response, dose-rate response and neutron response. The DXT-RAD dosemeter satisfied all the requirements of ISO 12794:2000(E), with the exception of its response at low photon energies and intermediate beta energies. However, it should be noted that other forms of the DXT-RAD dosemeter with a thinner entrance window are available to give an improved response to low-energy radiations.

  12. A new, passive dosemeter for gamma, beta and neutron radiations

    International Nuclear Information System (INIS)

    The Defence Science and Technology Laboratory (Dstl) provides personal radiation dosimetry to the UK Ministry of Defence. Dstl has recently developed a dosemeter that is based on a combination of thermoluminescent and etched-track detectors. The Dstl Combined Dosemeter is capable of assessing doses due to photons, beta particles and neutrons. This paper presents the laboratory type testing results for the Combined Dosemeter, and also describes the procedure for calibrating the dosemeter for use in workplace neutron fields. The Combined Dosemeter meets the type test requirements that are relevant to its intended applications, and gives neutron doses that are within 50% of the true dose in the workplaces in which it is used, even when the wearer has the potential to be exposed to a variety of neutron spectra (e.g. on board nuclear-powered submarines).

  13. A new, passive dosemeter for gamma, beta and neutron radiations.

    Science.gov (United States)

    Jones, L A; Stokes, R P

    2011-03-01

    The Defence Science and Technology Laboratory (Dstl) provides personal radiation dosimetry to the UK Ministry of Defence. Dstl has recently developed a dosemeter that is based on a combination of thermoluminescent and etched-track detectors. The Dstl Combined Dosemeter is capable of assessing doses due to photons, beta particles and neutrons. This paper presents the laboratory type testing results for the Combined Dosemeter, and also describes the procedure for calibrating the dosemeter for use in workplace neutron fields. The Combined Dosemeter meets the type test requirements that are relevant to its intended applications, and gives neutron doses that are within 50% of the true dose in the workplaces in which it is used, even when the wearer has the potential to be exposed to a variety of neutron spectra (e.g. on board nuclear-powered submarines). PMID:21346288

  14. Calibration and characterization of the extremities dosemeters

    International Nuclear Information System (INIS)

    The increase of the use of diagnostic techniques and therapy in the medical sector by using radiation sources, as in the nuclear medicine and interventionist radiology, is providing a great progress for the health improvement. However, these used techniques can generate an exposure workers increase. These expositions occur mainly on specific parts of the body such as the hands; these can stay in direct contact or very near to the radiation source due to the used technique during medical procedures. In both cases it is necessary a dosimetry of the specific parts of the body according to the national regulation on radiological protection; the Comissao Nacional de Energia Nuclear - CNEN responsible for the nuclear medicine through the CNEN-NN-3.01 standard and Agencia Nacional de Vigilancia Sanitaria - ANVISA responsible for the X ray diagnostic equipment through Portaria 453/98 standard of the Health department. In both cases the extremities dosimetry is necessary for these professionals checking the of application principles of radiological protection through the comparison of the found values of dose with the limits allowed for the current law. For this dosimetric verification it is necessary the characterization with the type tests and calibration of the extremities dosemeters, assuring the trustworthiness of the joined results. This work had as objective the calibration and characterization of the extremities dosemeters made at CDTN in the 'Personal Dose Equivalent for Extremities - Hp(0,07)', using a finger simulator in gamma radiation fields (60Co and 137Cs) and X rays; having the process of the system calibration accomplished based on international ISO/DIS 12794-1 standard, which establishes the performance criteria and tests for determining the performance of the thermoluminescence dosemeters to be used for measuring the radiation doses to the extremities due to photons. (author)

  15. Comparing different error-conditions in film dosemeter evaluation

    International Nuclear Information System (INIS)

    In the evaluation of a film used as a personal dosemeter it may be necessary to mark the dosemeters when possible error-conditions are recognised, such as errors that have an influence on the ability to make a correct evaluation of the dose value. In this project a comparison has been carried out to examine how two individual monitoring services, IMS [National Inst. of Radiation Hygiene (Denmark) (NIRH) and National Research Centre for Environment and Health (Germany) (GSF)], from two different EU countries mark their dosemeters. The IMS are different in size, type of customers and issuing period, but both use films as their primary dosemeters. The error-conditions examined are dosemeters exposed to moisture or light, contaminated dosemeters, films exposed outside the badge, missing filters in the badge, films inserted incorrectly in the badge and dosemeters not returned or returned too late to the IMS. The data are collected for the year 2003 where NIRH evaluated ∼50,000 and GSF ∼1.4 million film dosemeters. The percentage of film dosemeters is calculated for each error-condition as well as the distribution among eight different employee categories, i.e. medicine, nuclear medicine, nuclear industry, industry, radiography, laboratories, veterinary and others. It turned out, that incorrect insertion of the film in the badge was the most common error-condition observed at both IMS and that veterinarians, as the employee category, generally have the highest number of errors. NIRH has a significantly higher relative number of dosemeters in most error-conditions than GSF, which perhaps reflects that a comparison is difficult due to different systemic and methodical differences between the IMS and countries, e.g. regulations and monitoring programs etc. Also the non-existence of a common categorisation method for employee categories contributes to make a comparison like this difficult. (authors)

  16. PC based film badge dosemeter reader

    International Nuclear Information System (INIS)

    A dedicated stand alone film badge dosemeter reader based on a PC is designed for existing personnel monitoring films, kept in a multifilter cassette. The system is designed using a conventional, in use, single beam densitometer, with a little change in its hardware as an input device and all the features of the system are incorporated through PC software. The output of densitometer is fed to PC through an interface which controls the entire operation of the system. Details of the design and its performance are described. (author). 6 refs

  17. Area monitoring using neutron albedo thermoluminescence dosemeters

    International Nuclear Information System (INIS)

    Thermoluminescence dosemeters (TLD) were used for area monitoring around neutron sources applying the moderating sphere technique and the albedo technique in which LiF, 6LiF, 7LiF as well TLD-200 were used as TLD. Experimental results indicated that the thermoluminescence (TL) output for moderating sphere system is five times the TL output of the albedo system. In order to increase the TL output for the albedo system a paraffin slab was placed close to the albedo system. (author)

  18. Barium dithionate as an EPR dosemeter.

    Science.gov (United States)

    Baran, M P; Bugay, O A; Kolesnik, S P; Maksimenko, V M; Teslenko, V V; Petrenko, T L; Desrosiers, M F

    2006-01-01

    Electron paramagnetic resonance (EPR) dosimetry is growing in popularity and this success has encouraged the search for other dosimetric materials. Previous studies of gamma-irradiated barium dithionate (BaS(2)O(6) x 2H(2)O) have shown promise for its use as a radiation dosemeter. This work studies in greater detail several essential attributes of the system. Special attention has been directed to the study of EPR response dependences on microwave power, irradiation temperature, minimum detectable dose and post-irradiation stability. PMID:16565205

  19. Thermal neutron dosimetry using MOSFET dosemeters

    Energy Technology Data Exchange (ETDEWEB)

    Fragopoulou, M., E-mail: fragom@auth.g [Aristotle University of Thessaloniki, Physics Department, 54124 Thessaloniki (Greece); Siskos, S.; Manolopoulou, M.; Zamani, M. [Aristotle University of Thessaloniki, Physics Department, 54124 Thessaloniki (Greece); Sarrabayrouse, G. [LAAS du CNRS, University of Toulouse, 7 Av. Du Colonel Roche, 31077 Toulouse (France)

    2009-10-15

    Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) with a LiF powder placed on their surface were used as neutron dosemeter. The effect of thermal neutron irradiation on the threshold voltage of the transistor was studied in order to determine the sensitivity of these detectors. Irradiations were performed at the thermal column of the reactor in IPTA, Demokritos, Athens and at the subcritical reactor of Nuclear Physics Laboratory, Thessaloniki. The sensitivity of the MOSFETs as a function of thermal neutron dose was found to be practically linear up to 100 mSv. The lower detectable dose appears to be depended on the dose rate.

  20. Improvement of personal dosimetry - Digital pocket dosemeter

    International Nuclear Information System (INIS)

    Physical dosimetric surveillance of professional groups working with various radiation sources is a regular procedure in Croatia, established almost 40 years ago. Data available point out that the majority of professionals under surveillance are those employed in medical facilities, most of them working with X-ray sources. Depending on the nature of professional activities, personnel occupationally exposed to radiation sources are obliged to wear either film badge, TLD or film+TLD badge. Unfortunately, due to the line of data processing, all standard dosemeters have the same disadvantage i.e. up to 40 days delay in dose reporting, regarding the time of actual exposure. The significance of such a delay raises in cases when radiation dose was received within the short time or when technical failure on the operating unit(s) is suspected. Bearing this in mind, the additional dosimetric monitoring becomes an imperative. Therefore, we decided to introduce a palette of digital pocket dosemeters, meant to be used in different workplaces in the radiation zone, each of them being adjusted to the specificities of a particular workplace

  1. A prototype personal neutron dosemeter with one silicon diode

    International Nuclear Information System (INIS)

    The performance of a personal neutron dosemeter with a single silicon diode using a linear combination of its pulse height information was studied. Its dosimetric behaviour in fields with neutrons of different energy and directional distribution is shown for neutron energies ranging from thermal to 100 MeV and for directions of incidence ranging from frontal to lateral. The dosemeter is photon-insensitive and its dose detection threshold is at about 20 μSv. The dosimetric characteristics are compared with those of commercial dosemeters based on silicon detectors. (author)

  2. Dosimetric characteristics of a TLD dosemeter with extremities

    International Nuclear Information System (INIS)

    It was designed a TLD dosemeter for the monitoring of the extremities. This one consists in a metallic ring with a circular orifice where is arranged a T L detector of LiF: Mg,Ti (Model JR1152C) 5 x 5 x 0.8 mm3 covered by a polyethylene fine layer. In this work were studied the dosimetric properties of the dosemeter for its application in the dosimetry of extremities for photonic radiation. the results obtained allow conclude that the designed dosemeter can be used for the extremities monitoring. (Author)

  3. Response of Alanine Dosemeter to Heavy Ions

    Institute of Scientific and Technical Information of China (English)

    LiWenjian; SuXu; YangYingjie; YuanJianlei; DangBingrong; WangXiao; MaQiufeng; ZhouLibin; HaoJifang; MaoShuhong

    2003-01-01

    The amino acid L-α-alanine has been investigated for use as a radiation detector in low and high LET radiation fields[1]. The radiatioa detector is cheap and easy to handle. The radiation inducing free radicals are stable at normal laboratory conditions for doses below 104 Gy over a long period of time, which makes the detector useful for intercomparison and documentation purposes. The dosimetric features of alanine-based electron spin resonance (ESR) detectors in high energy electron beams used in radiotherapy were considered[2]. The 5 mm long alanine detectors were found to be the most suitable for carrying out in vivo dosimetry on patients undergoing electron beam radiotherapy. However, data concerning dosimetry of the alanine dosemeter to heavy charged particles are lacking, especially in China.

  4. Active electronic personal dosemeter in interventional radiology

    International Nuclear Information System (INIS)

    A recently developed active electronic personal dosemeter (AEPD) was utilised in order to measure the levels and the structure of occupational exposure to scattered X-ray radiation of medical staff who performed percutaneous revascularisation therapy that involves interventional radiology (IR) on the pelvis and upper leg arteries. The AEPDs, placed on the operators' and assistants' chests, that is, above the protective apron, continuously measured and recorded the received doses and, as a novelty, dose rates as a function of time, thus yielding a unique record of occupational doses and dose rates pattern at the working place. This paper presents and discusses one typical daily pattern in which seven percutaneous interventions were performed. (authors)

  5. Measurement analysis using the Fricke dosemeter

    International Nuclear Information System (INIS)

    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

  6. European intercomparison of diagnostic dosemeters: performance of the programme

    International Nuclear Information System (INIS)

    This paper reports on participants, organisation and measuring conditions of the European-wide intercomparison programme of dosemeters used in diagnostic radiology, in a programme carried out in 1990 on protectorate of the CEC. (author)

  7. European intercomparison of diagnostic dosemeters: performance of the programme

    International Nuclear Information System (INIS)

    This paper reports on participants, organisation and measuring conditions of the European-Wide intercomparison programme of dosemeters used in diagnostic radiology in a programme carried out in 1990 on protectorate of the CEC

  8. Household and workplace chemicals as retrospective luminescence dosemeters

    DEFF Research Database (Denmark)

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

    2002-01-01

    , there are Other potential unheated crystalline materials found in the domestic and industrial environment which may also act as retrospective dosemeters, and may be considerably more sensitive. We have Surveyed the thermoluminescent and optically stimulated luminescent (OSL) characteristics of several...

  9. A CR-39 track dosemeter for routine individual neutron monitoring

    International Nuclear Information System (INIS)

    A personal neutron dosemeter for routine individual monitoring is proposed. It is based on a CR-39 track detector covered on three separate areas by converters with different boron contents and inserted into a commercial TLD albedo dosemeter capsule. The dose readings from three areas of the electrochemically etched CR-39 detector are combined to yield a dose equivalent response which is almost independent of the incident neutron energy in the range from thermal neutrons up to 20 MeV. In addition, the dose contributions of thermal, intermediate and fast neutrons can be determined separately. Unlike the TLD albedo dosemeter, which in general requires prior in-field calibration and whose use is then restricted to that field, this dosemeter can be used in neutron fields without any knowledge of the spectral distribution with the same calibration factor. The angular dependence of the dosemeter's response has been measured and compared with that of the directional dose equivalent H'(10). The lower limit of detection is 0.15 mSv. It is possible to obtain an independent, second dose reading from the same Cr-39 detector for neutron energies above 100 keV. The dosemeter has also been successfully tested for use in accident dosimetry applying chemical etching and an optical density reading of the CR-39 detector. (author)

  10. Characterization of the personal thermoluminescent dosemeter of LiF: Mg, Ti + Ptfe

    International Nuclear Information System (INIS)

    The objective of this work is to characterize the thermoluminescent dosemeters taken place in the laboratory in form of pellets of LiF: Mg, Ti + Ptfe like personal dosemeters, subjecting them to the operation tests proposed by the international standards and comparing them with the TLD-100, the Tl dosemeter more used at the moment for personal dosimetry

  11. Testing of a TLD and a direct ion storage (DIS) dosemeter for use as a personal dosemeter

    International Nuclear Information System (INIS)

    The dosimetric performance characteristics of a TLD system (Harshaw Model 6600 with TLD-100 LiF-pellets) installed at the Personal Dosimetry Laboratory of the Finnish Centre for Radiation and Nuclear Safety have been tested. Tests performed are based on the IEC Standard 1066. Along with the TLD system some novel direct ion storage (DIS) dosemeters (Rados Technology Oy) were also included in some of the tests and the results for DIS dosemeters were also compared with the performance criteria of IEC 1066. Direct comparison of the results between TLDs and DIS dosemeters is not made, as only a few of early stage design DIS dosemeters were available. The tests were made of photon radiation using the personal dose equivalent at 10 mm depth, i.e. Hp(10), as a testing quantity. Based on the recommendations of ICRU and ICRP and the results obtained the applicability of both types of dosemeters for use in an official personal dose monitoring system is assessed. (Author)

  12. Conversion from dosemeter readings to effective dose in individual dosimetric monitoring: effect of anisotropy of photon fields and dosemeter design

    International Nuclear Information System (INIS)

    Monte Carlo simulation (MCNP-4B code, ADAM phantom) was employed in order to estimate organ doses and doses to personal dosemeters of particular commercial design (one type of Harshaw dosemeter and two designs of RADOS dosemeters) in situations of irradiation of a person in photon radiation fields. For each photon energy and beam direction the partial conversion coefficients were calculated providing thus raw data for modeling of effective conversion coefficient in any photon radiation field. In practical situations, when specific orientation of a body in radiation field is not known or a person is changing his position and orientation, the most robust parameter representing geometry of exposure is anisotropy of radiation field. In order to assess effective conversion coefficients for variety of workplace conditions, both anisotropic field configuration and orientation of a person in radiation field were stochastically simulated and 95% percentile of stochastic distribution was taken as a value of effective conversion coefficient for given conditions of exposure. The value of effective conversion coefficient depends on anisotropy of radiation field and can be quantitatively derived for appropriate classes of anisotropy. For quasi-isotropic and moderately anisotropic fields effective conversion coefficient does not exceed unity (e.g. Hp(10) maintains conservatism) for all considered dosemeter types, while in strongly anisotropic fields Hp(10) is not conservative anymore and can underestimate effective dose. The described approach is illustrated by examples of appropriate effective conversion coefficients for several commonly used dosemeter types. (author)

  13. Official dosimetry with personal electronic dosemeters - The framework in Germany

    International Nuclear Information System (INIS)

    In Germany, personal electronic dosemeters (AEPDs) are presently applied mainly for operational radiation protection monitoring particularly in nuclear power engineering companies, large hospitals and research centres. This is done in addition to the official dosimetry of record. Therefore, frequently, double monitoring occurs - officially and operationally. A crucial advantage of AEPDs compared with passive dosemeters is the ability to adapt the monitoring period to the working time in controlled areas and to allow an immediate readout of the dose after leaving the controlled area, e.g. a job-related monitoring is possible by correlating the readout dose with the job performed. Germany started a general research project, consisting of two parts, for an optimised implementation of personal electronic dosemeters into official dosimetry. The use of AEPDs as official dosemeters depends on an approval by Federal and Federal State ('Laender') authorities as an official dosimetry system, which has to comply with special requirements ensuring that the legal requirements are fulfilled. The formulation of these special requirements is in the focus of part one of the research project, supervised by the Federal Office for Radiation Protection (BfS) and performed by the Gesellschaft fuer Anlagen-und Reaktorsicherheit (GRS) mbH. As a result of part one, a framework was developed which is the basis for a future technical implementation project. Part one is described in the paper, while part two is still to be initiated and will deal with the implementation and testing phase of the introduction of personal electronic dosemeters as official dosemeters. (authors)

  14. 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...... during 1994. The intercomparison was organised by the Physikalisch Technische Bundesanstalt (PTB), Braunschweig, Germany, and by the Riso National Laboratory, Roskilde, Denmark. This paper describes the intercomparison experiments performed at the newly established Riso Natural Environmental Radiation...... 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...

  15. The influence of the energy distribution of workplace fields on neutron personal dosemeter reading

    International Nuclear Information System (INIS)

    Variations in the energy dependence of response of neutron personal dosemeters cause systematic errors in the readings obtained in workplace fields. The magnitude of these errors has been determined theoretically by folding measured and calculated workplace energy distributions with dosemeter response functions, to determine the response of a given personal dosemeter in that field. These results have been analysed with consideration of the dosemeter response to various calibration spectra, and with reference to different workplaces. The dosemeters in the study are discussed in terms of the workplaces for which they can be suitably calibrated. Deficiencies in the published neutron energy distributions are identified

  16. Comparison on characteristics of radio-photoluminescent glass dosemeters and thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    The radio-photoluminescent glass dosemeter (RPLGD) system is applicable for measurement of radiation dose of X-rays and gamma rays by using radio-photoluminescent glass (silver-activated phosphate glass). When the radio-photoluminescent glass is exposed to ionizing radiation, stable luminescent centres are created. During pulsed ultraviolet laser excitation (337.1 nm) in the reader, the centres emit a radiation induced orange fluorescent light (600-700 nm). This phenomenon is called radio-photoluminescence. This study compared the RPLGD system with lithium fluoride (LiF) thermoluminescence dosimetry system and the results of the study revealed that the RPLGD had not only good basic characteristics for reproducibility of readout value, dose linearity, energy dependence and fading, but also infinite repeatable measurements and could be one of the most important radiation dose measurement instruments. (authors)

  17. EURADOS intercomparisons on whole body and extremity dosemeters (2008–2009) – Results and comparison of different dosemeter designs

    International Nuclear Information System (INIS)

    The EURADOS (European Radiation Dosimetry Group) working group (WG2) on Harmonisation of Individual Monitoring in Europe has shown that intercomparisons are fundamental for harmonisation of individual monitoring. As a result of these considerations, EURADOS started to prepare a series of continuous intercomparisons for individual monitoring services (IMS) in Europe. EURADOS has now successfully executed two intercomparison exercises, one for whole body dosemeters (2008) and one for extremity dosemeters (2009). Both exercises were performed without external funding, all costs being covered by the participants’ fees. More than 120 (!) different – mainly passive – dosimetry systems were tested from all over Europe until now and the results were analysed and compared. Although scientific studies were not the primary objective of these exercises specific additional information about the tested systems supplied by the participants for statistical analysis allows a detailed analysis of these results with respect to different parameters like dosemeter type, detector material, filter thickness or others design parameters. The influence of such parameters on the response values of the dosemeters is analysed and discussed in this paper. Both energy response as well as directional response for beta and photon radiation are considered. The influence of different design parameters e.g. detector material, is analysed by comparing the frequency distribution of the response values for different dosemeter groups. Pronounced differences for different detector materials (LiF:Mg,Ti, LiF:Mg,Cu,P and Li2B4O7/CaSO4) were found. The paper gives a comprehensive overview on the performance of various European dosimetry services and the influence of the dosemeter design on the resulting response values.

  18. Electronic personal neutron dosemeters for high energies: Measurements, new developments and further needs

    International Nuclear Information System (INIS)

    The results of measurements with neutron energies up to 60 MeV are shown for the personal neutron dosemeters Thermo Electron EPD-N2, ALOKA PDM-313 and the PTB prototype dosemeter DOS-2002. All dosemeters show dose equivalent responses that are about a factor of 10, too high at 60 MeV. A new prototype dosemeter - called DOS-2005 - consisting of a detector with a thin effective layer of 6 μm has been set up at PTB. The dose equivalent response of this dosemeter and that of the newly developed dosemeter SAPHYDOSE-N was measured up to 19 MeV. Both dosemeters indicate a more flat response at high neutron energies. Further needs - optimisations, measurements and calculations - for use at high-energy accelerators and in space are discussed. (authors)

  19. Some characteristics of the AEOI Neutriran Albedo Neutron Personnel Dosemeter

    International Nuclear Information System (INIS)

    The Neutriran Albedo Personnel Neutron Dosemeter (NAPND) is based on the combination of a sensitive polymer such as polycarbonate (PC) in contact with 6LiF or 10B pellets in a cadmium cover. By adding a 10B pellet in front, the design of the dosemeter can be such that when worn on the body, direct thermal neutron induced alpha tracks (TNIAT), albedo neutron induced alpha tracks (ANIAT) and fast neutron induced recoil tracks (FNIRT) can be simultaneously detected in a single electrochemically etched PC foil. To establish a national personnel neutron dosimetry service in Iran, different parameters such as the effect of 10B(n,α)7Li convertor thickness, Cd thickness and its diameter, dosemeter distance from the phantom, dosemeter angle with phantom and directional response were studied using different phantoms. Under optimised conditions, a sensitivity of 1500 tracks.cm-2.mSv-1 for 252Cf neutrons with a lowest value of 0.05 mSv was measured. The results of these studies are reported and discussed. (author)

  20. About the measurements systems with pen and thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    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)

  1. 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)

  2. 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...

  3. Establishing local workplace field correction factors for neutron personal dosemeters

    International Nuclear Information System (INIS)

    The present personal neutron dosemeters still need local correction factors to be able to provide accuracy comparable with photon dosemeters. Characterisation of the local neutron field is an indispensable part of neutron dosimetry to obtain such correction factors. It is often overlooked that besides characterisation in the neutron energy also the directional distribution of neutrons plays a crucial part in this characterisation. The authors have done such characterisation in the energy and angle for four workplace fields in Paks NPP. For this a relatively simple approximation method was used using the Nprobe for the energy distribution and measurements on the six sides of the slab phantom with personal dosemeters for the directional distribution. This allowed one to estimate a reference neutron Hp(10) rate and to compare it with the response of several neutron personal dosemeters. In October 2011, a measurement campaign was set-up in Paks NPP, which is a VVER reactor type. The measurements were performed to estimate reference values for personal dose equivalent rates dHp(10)/dt and to evaluate the behaviour of several personal dosemeters at different locations inside the plant. Two locations in the pump room and two locations in the reactor hall were chosen. Instead of just assuming that the fluence is unidirectional or that the fluence is isotropic, an attempt was made to estimate the directional distribution of the neutron field using a relatively simple measurement procedure. A number of active and passive personal dosemeters were placed on the six faces of a slab phantom and the results were analysed to obtain partial fluences in several directions of incidence. This method has important limitations, but is relatively simple to perform. The results show that it is very important to include the directional distribution in the Hp(10) evaluation. When comparing Hp(10)/dt and H*(10)/dt, H*(10) can be considered a conservative value for Hp(10). In the pump room H

  4. On the use of albedo dosemeters at the Dukovany nuclear power plant

    International Nuclear Information System (INIS)

    The response of the albedo dosemeter which is used as a personnel neutron dosemeter at the Dukovany nuclear power plant was studied. The design of the dosemeter was modified against the original version, whereby its dimensions were reduced and the dosemeter was augmented with a Cd shield to protect it against incident thermal neutrons. The study showed that the neutron spectrum inside the nuclear power plant varies over a wide range, and a correct interpretation of the albedo dosemeter data requires the use of a factor whose values can differ by as much as an order of magnitude. The results of the study allowed a procedure to be recommended for determining the Hp(10) value of the plant personnel using this device as an individual neutron dosemeter. (author)

  5. 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...

  6. The use of extremity dosemeters in a hospital environment

    International Nuclear Information System (INIS)

    A general overview is given on the use of extremity dosemeters, their calibration, the units and phantoms to be used. One of the major applications of extremity dosemeters is to monitor the personnel in a hospital environment. In nuclear medicine, brachytherapy and interventional radiology (IR) skin doses to hands and legs can be substantial. Here, we report on two studies that are presently being undertaken in Belgium. The first one tries to map the dose distribution on the hands, in function of the manipulation in nuclear medicine. Some preliminary results are also given from a nationwide survey study for patient and personnel doses during IR and cardiology. The radiologists' hands, legs and forehead are monitored during a whole range of procedures in different hospitals. (authors)

  7. Photon personal dosemeter calibration based on ISO 4037-3

    International Nuclear Information System (INIS)

    The aim of this paper is to present the results of the influence of this new standard compared with the previously approved calibration protocol. The former calibration protocol used a 30 cm x 30 cm x 15 cm PMMA phantom and included back-scatter correction factors estimated from Monte Carlo calculations. Previous studies (Ginjaume et al., 2001) had shown, for a specific type of dosemeter, that the differences between both calibrations were very small, within 2%. This work planned, within the framework of the 2001 national intercomparison, to enlarge the preliminary conclusions by studying the influence of the calibration procedure on a larger set of dosemeters, which would be representative of the different Spanish Dosimetry Services. We were also interested in confirming that the new calibration procedure would not influence the general performance of the services and the corresponding registered doses

  8. Household and workplace chemicals as retrospective luminescence dosemeters

    International Nuclear Information System (INIS)

    In the development of techniques for the retrospective assessment of the dose 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 found in household earthenware and almost all types of bricks and concrete. Their main disadvantages are variable and often low sensitivity, and the possibility of a comparatively large natural dose prior to the accident, depending on the age of the building and the type of building material. However, there are other potential unheated crystalline materials found in the domestic and industrial environment which may also act as retrospective dosemeters, and may be considerably more sensitive. We have surveyed the thermoluminescent and optically stimulated luminescent (OSL) characteristics of several such chemicals and this paper reports on the OSL sensitivity, the size of the residual dose immediately after manufacture, stability and derived minimum detection limits. (author)

  9. Performance and approval procedures for active personal dosemeters

    International Nuclear Information System (INIS)

    Active personal dosemeters (APDs) are well accepted as useful and reliable instruments for individual dosimetry measurements. The increasing concern about studying the behaviour of APDs in pulsed fields is illustrated through revision of the results of the most representative studies on the performance of APDs in the last 5 y. The deficiencies of APDs in pulsed fields are discussed together with proposals to overcome them. Although there are no legal constraints or technical limitations for recognising APDs for legal dosimetry in facilities with continuous radiation fields, APDs continue to be mainly used as operational dosemeters. The approval procedures applicable to APDs, especially the approach undertaken by Germany, are presented. Finally, some trends in the developments and use of APDs are summarised. (authors)

  10. Test and optimization of two routine dosemeters for the dose quantity Hp(3)

    International Nuclear Information System (INIS)

    The individual monitoring service Seibersdorf uses two different passive dosemeter types based on thermo luminescence (TL) detectors for monitoring occupationally exposed persons in Austria. Whole body personal dosemeters for the personal dose equivalent quantities Hp(10) and Hp(0.07) worn on the trunk and dosemeters for the extremities for Hp(0.07) worn on a finger or wrist. Both routine dosemeters were calibrated and tested in terms of the personal dose equivalent Hp(3) assuming that the whole body dosemeter is worn on the chest (without or above a lead apron) and the modified ring/wrist dosemeter using a special strap worn on the forehead near the eyes (head band dosemeter). The test results show that it is possible to measure the dose quantity Hp(3) with these dosemeters that were originally not designed for this dose quantity. Only changes in the dose calculation algorithm and in the choice of the reference radiation quality were necessary to fulfil the requirements given in international standards for passive dosemeters in a wide energy (20 keV–1.3 MeV) and angular range (0°–60°). - Highlights: • Whole body dosemeter for Hp(10) and Hp(0.07) can also be used for Hp(3). • The dose algorithm for whole body dosemeter can be changed for Hp(3). • Extremity dosemeter for Hp(0.07) can also be used for Hp(3) on the forehead. • The reference energy has to be changed for Hp(3)

  11. Development of an universal personal dosemeter using semiconductor sensors for mixed radiation fields

    International Nuclear Information System (INIS)

    The objective of the project is to develop a pocket sized personal dosemeter using semiconductor materials. This dosemeter will be able to give a reading as close as possible to the dose equivalence in radiation fields existing around reactors, accelerators, X and gamma sources. Furthermore, the pocket dosemeter will give a flat energy response according to the most recent ICRP recommendations. (R.P.) 2 figs

  12. Thermoluminescence sensitivity variations in LiF PTFE dosemeters incurred by improper handling procedures

    CERN Document Server

    Mason, E W; MacKinlay, Alistair F; Saunders, D

    1975-01-01

    A systematic study of some anomalous darkening effects and thermoluminescence sensitivity variations observed in LiF:PTFE thermoluminescent dosemeters is described. Various likely causes of such effects have been investigated. The manufacturer's recommended cleaning procedures have been found to be inadequate and, in some cases, have been found to actually promote discolouration of the dosemeters. Recommendations are given for the successful use of LiF:PTFE thermoluminescent dosemeters in personal dosimetry.

  13. Aluminium nitrate ceramics: A potential UV dosemeter material

    DEFF Research Database (Denmark)

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

    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...... Al2O3:C; and (4) a large dynamic range TL signal (5 orders of magnitude). Although there is relatively high fading, it is demonstrated that AIN is a feasible material for UVR dosimetry using short integration times....

  14. Achievable precision and accuracy of dose determinations from routine dosemeters

    International Nuclear Information System (INIS)

    The concepts of accuracy and precision as associated with dose determinations from routine dosemeters are analyzed. The factors which are most important when considering the accuracy of such measurements are then discussed. These include environmental conditions such as humidity, temperature, dose rate and time since irradiation. Some examples are presented. It is concluded that precision under identical irradiation conditions for reproducibility can be ± 2% at the 95% confidence level. The corresponding accuracy should not be more than ± 5%. (U.K.)

  15. Dose equivalent conversion coefficients, instrument and dosemeter responses for a set of neutron radiation fields

    International Nuclear Information System (INIS)

    The results are presented of calculations of spectrum (energy and angle) weighted conversion coefficients from fluence to the quantities effective dose equivalent, ambient dose equivalent (H*(10)), directional dose equivalent at 10 mm (H'(10)) and MADE; and of the responses per unit fluence of a spherical rem meter, a nuclear emulsion dosemeter, an albedo dosemeter and a PADC (CR39) dosemeter, for a set of neutron spectra. Calculations have been performed for both unidirectional fields and for rotational symmetry. The values of conversion coefficients and instrument and dosemeter responses are compared. (author)

  16. Development of active environmental and personal neutron dosemeters

    International Nuclear Information System (INIS)

    For neutron dosimetry in the radiation environment surrounding nuclear facilities, two types of environmental neutron dosemeters, the high-sensitivity rem counter and the high-sensitivity multi-moderator, the so-called Bonner ball, have been developed and the former is commercially available from Fuji Electric Co. By using these detectors, the cosmic ray neutrons at sea level have been sequentially measured for about 3 y to investigate the time variation of neutron spectrum and ambient dose equivalent influenced by cosmic and terrestrial effects. Our Bonner ball has also been selected as the neutron detector in the International Space Station and has already been used to measure neutrons in the US experimental module. The real time wide-range personal neutron dosemeter which uses two silicon semiconductor detectors has been developed for personal dosimetry and is commercially available from Fuji Electric Co. This dosemeter has good characteristics, fitted to the fluence-to-dose conversion factor in the energy range from thermal energies to several tens of mega-electron-volts and is now widely used in various nuclear facilities. (authors)

  17. Improved characterization of the NRPB PADC neutron personal dosemeter

    International Nuclear Information System (INIS)

    Full text: The NRPB PADC neutron personal dosimetry service has been operating routinely since 1986. During its years of operation, many changes have been introduced, notably to the etch process, detector material, read system and the holder. The fast-neutron energy dependence of response of the dosemeter, 100 keV to 15 MeV, has been characterized using a set of monoenergetic neutron fields. Below 100 keV, the response determination has been restricted to a thermal calibration supported by MCNP calculations. New data from the SIGMA field at Cadarache, France and GKSS in Germany, allied to improved MCNP calculations have been used to enhance the understanding of the response to thermal and intermediate-energy neutrons. Additionally, a new set of monoenergetic irradiations up to 19 MeV performed at the Physikalisch-Technische Bundesanstalt has augmented the existing data for the fast-neutron response. These show great consistency with data previously obtained at the National Physical Laboratory in the UK. The response between the measured and calculated energies has been evaluated using measurements in fields with broad energy distributions. The new response characteristics of the field have been folded with workplace fields representative of those in which the dosemeter is worn, so that the optimum calibration for the dosemeter can be obtained. (author)

  18. Official dosimetry with individual electronic dosemeters - the concept in Germany

    International Nuclear Information System (INIS)

    Full text: Presently, in Germany passive dosemeters (film batches, RPL, TLD) are used for the official individual monitoring of occupational exposed personal. The application of electronic individual dosemeters (EPD) is carried out mainly for the operative radiation protection control particularly in nuclear power engineering companies, big hospitals und research centres. This means in such institutions double monitoring exists - legally and operatively. A crucial advantage of EPD compared to passive dosemeter is the possibility to adapt the monitoring period to the working time in the control area, e.g. a job related monitoring is available. Germany started a project for an optimized implementation of EPD into the official dosimetry. Objective of the project whose results will be described in the paper is the harmonization of radiation protection of companies workers and outside workers concerning the record of individual and job related exposures. The approval of the EPD by the Federal and Laender authorities as an official dosimetric system demands the implementation of special requirements concerning the data acquisition, data transfer and data evaluation. These issues are focuses of the Federal research project, supervised by the Federal Office for Radiation Protection (BfS) and performed by the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS), Cologne to develop a concept in the first stage. (author)

  19. New operational quantities and the angular response of personal dosemeters

    International Nuclear Information System (INIS)

    New quantities, especially the ambient dose equivalent H* and the personal dose equivalent Hp at a specified point within the body have been defined by international rules. Practically, the measurement instrument cannot be placed at this point, but at the nearest point at the surface of the body. Such a difference in position results in errors varying with the incident radiation. The definition of these new quantities raises (1) the problem of the appropriateness of the present instruments and (2) the comparison with the legal film dosemeter, which is practically isotropic. The use of new instruments, especially in nuclear power plants (NPPs), results in measurement discrepancies between photographic and operational dosemeters and thus required further work on the angular response of operational dosemeters. The angular variations of the operational quantity Hp were considered in order to supplement the tables of an IEC draft for angle values ranging between 75 deg and 180 deg by means of simple calculations not contradictory with more thorough studies. (authors). 13 refs., 15 figs., 1 tab., 1 appendix

  20. Micro-dosemeter instrument (MIDN) for assessing risk in space

    International Nuclear Information System (INIS)

    Radiation in space generally produces higher dose rates than that on the Earth's surface, and contributions from primary galactic and solar events increase with altitude within the magnetosphere. Presently, no personnel monitor is available to astronauts for real-time monitoring of dose, radiation quality and regulatory risk. This group is developing a prototypic instrument for use in an unknown, time-varying radiation field. This micro-dosemeter-dosemeter nucleon instrument is for use in a space-suit, spacecraft, remote rover and other applications. It provides absorbed dose, dose rate and dose equivalent in real time so that action can be taken to reduce exposure. Such a system has applications in health physics, anti-terrorism and radiation-hardening of electronics as well. The space system is described and results of ground-based studies are presented and compared with predictions of transport codes. An early prototype in 2007 was successfully launched, the only solid-state micro-dosemeter to have flown in space. Published by Oxford Univ. Press on behalf of the US Government 2011. (authors)

  1. On the calibration of radiotherapy dosemeters in Australia

    International Nuclear Information System (INIS)

    Full text: Dosemeters for external beam radiotherapy are calibrated in Australia by ARPANSA, against the national primary standards of exposure and absorbed dose. The primary standards are free air chambers for exposure at low and medium energy X-rays, a graphite cavity chamber for exposure at 60Co, and a graphite calorimeter for absorbed dose at 60Co and high energy (MV) X -rays. Radiotherapy dosemeters are calibrated against these standards using a well documented formalism to provide calibration factors suitable for use with dosimetry protocols. A dosemeter usually comprises an ionization chamber connected to an independent electrometer. These are calibrated separately if possible. A combined calibration factor is reported together with the electrometer calibration factor (sensitivity). The dosimetry protocol used in radiotherapy centres in Australia and New Zealand is currently the simplified version of the IAEA TRS277 protocol, published by the New Zealand NRL and recommended by the ACPSEM. This protocol requires the use of an exposure or air kerma calibration factor at 60Co (Nx or Nk) to evaluate the absorbed dose to air calibration factor ND. The chamber is then placed in a water phantom with its centre displaced from the reference point by peff. ARPANSA can also supply calibration factors in absorbed dose to water (ND,w), as required as input to the new IAEA CoP. If an absorbed dose to water calibration factor is used by the radiotherapy centre, the chamber should be placed with its centre at the reference point in the water phantom. ARPANSA has for some years coordinated the participation of Australian radiotherapy centres in the IAEA TLD Quality Audit service. Note that this service does not represent a calibration and should not be referred to as such. The only calibration is that provided by ARPANSA for a reference dosemeter at each radiotherapy centre. As soon as the ANSTO SSDL is operational, calibrations of reference dosemeters will also be available

  2. Results of an inquiry concerning experience gained in the use of thermoluminescent and phosphate glass dosemeters

    International Nuclear Information System (INIS)

    The report summarizes the results of an inquiry among users of thermoluminescent and phosphate glass dosemeters, carried out within the framework of the working group for 'external radiation dose measurement' of the Fachverband fuer Strahlenschutz eV. The data presented came in from 24 laboratories, showing their experience in the use of 38 different dosemeters. (orig.)

  3. Studying the sensitivity of personnel neutron dosemeter PDM-303 to high-energy neutron radiation

    International Nuclear Information System (INIS)

    The sensitivity of the PDM-303 personnel neutron dosemeter to high-energy radiation behind the U-70 accelerator shield and neutron calibration fields of IHEP is investigated. It is found that this dosemeter has high sensitivity to high-energy neutrons. The fact requires introduction of correcting calibration coefficients in the case of its application in conditions of the U-70 accelerator radiation

  4. Development of Two-Dosemeter Algorithm for Better Estimation of Effective Dose Equivalent and Effective Dose

    International Nuclear Information System (INIS)

    An optimal algorithm, which suitably combines two dosemeter readings, one dosemeter on the chest and the other on the back, for better estimation of effective dose equivalent (HE) and effective dose (E), was developed by utilising hundreds of broad parallel photon beam irradiation geometries. The developed algorithm, weighting front (chest) and back dosemeter readings by 0.58 and 0.42, respectively, was found to be superior to other currently available algorithms, neither underestimating HE or E by more than 14%, nor overestimating by more than a few tens of a per cent for a broad range of frontal and dorsal incident beams. Like other algorithms, however, this algorithm tends to overestimate HE and E significantly for the lateral, overhead and underfoot beam directions. This study also suggests that this overestimation problem significantly decreases when one uses typical commercial dosemeters instead of isotropic-responding dosemeters. (author)

  5. Performance of several active personal dosemeters in interventional radiology and cardiology

    International Nuclear Information System (INIS)

    Active personal dosemeters (APDs) are very useful instruments for optimizing radiation protection of workers and for increasing worker’s awareness of unexpected exposures. The challenge of monitoring personal equivalent doses with APDs in interventional fluoroscopy is that they must be sensitive to low energy photon beams and be able to record high dose rates. The aim of this work is to verify both the performance and the reliability of four active personal dosemeters (APDs) and one direct ion storage (DIS) dosemeter in typical X-ray radiation fields used during interventional radiology and cardiology (IR/IC) procedures. The values of the personal dose equivalent at a depth of 10 mm measured by the APDs are compared with the response of a whole body thermoluminescence dosemeter (TLD) as a reference dosemeter. The response is found to be satisfactory in the tested situations.

  6. Electron scattering effects on absorbed dose measurements with LiF-dosemeters

    International Nuclear Information System (INIS)

    The investigation deals with absorbed dose measurements with solid wall-less dosemeters. Electron scattering complicates both measurement of absorbed dose and its theoretical interpretation. The introduction of the dosemeter in a medium causes perturbations of the radiation field. This perturbation and its effect on the distribution of the absorbed dose inside the dosemeter is studied. Plane-parallel LiF-teflon dosemeters (0.005 - 0.1 g.cm-2) are irradiated by a photon beam (137Cs) in different media. The investigation shows that corrections must be made for perturbations caused by electron scattering phenomena. Correction factors are given for use in accurate absorbed dose determinations with thermoluminescent dosemeters. (Auth.)

  7. A Method for evaluating personal dosemeters in workplace with neutron fields

    International Nuclear Information System (INIS)

    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. (authors)

  8. 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. PMID:21565843

  9. Results of the IAEA/RCA personal dosemeter intercomparison

    International Nuclear Information System (INIS)

    The intercomparison of personal dosemeters for photon was carried out between 1990 and 1996 as part of the IAEA/RCA 'strengthening of radiation protection infrastructure' project. Japan Nuclear Cycle Development Institute participated in the intercomparison as one of the in-house personal dosimetry service organizations in Japan and also served the host irradiating laboratory. This report summarizes the dose evaluation results obtained from the JNC-TLD badges in the past four intercomparison programs. In the latest intercomparison the evaluated doses agreed to the reference doses with an accuracy of 10%. (author)

  10. Active personal dosemeters for individual monitoring and other new developments

    International Nuclear Information System (INIS)

    In this paper, we will present a first (but not complete) status description of active personal dosemeters (APDs) and their implementation in European countries. In modern radiation protection practices, APDs are becoming absolutely necessary operational tools for satisfying the ALARA principle. Despite their success, they are relatively new for individual monitoring of workers. Regulation, legal requirements and calibration procedures are different in European member states. A catalogue of commercially available and prototype devices is presented. Improvement on devices and in implementation of calibration method are expected in the forthcoming years. End-user feedback experience and requirements are reported. (authors)

  11. Method of making isodose curve using thermoluminescence dosemeter

    International Nuclear Information System (INIS)

    Line source of 60Co in the form of needles and tubes are extensively used in radiotherapy in moulds, implants, and intracavitary techniques for the treatment of malignant lesions. It is important to have isodose distributions in tissue for those source for purposes of treatment planning. The isodose distributions have been obtained experimentally by using tinny lithium-fluoride (Lsub(i)F) thermoluminescent dosemeters (TLD) and they are compared to the theoretical results. The distinct advantages of Lsub(i)F (TLD) in such measurements are briefly discussed. (author)

  12. Calibration, performance and type testing of personal dosemeters used in ionising-radiation applications in Greece.

    Science.gov (United States)

    Boziari, A; Hourdakis, C J

    2007-01-01

    Active Personal Dosemeters (APDs) are widely used in real-time personal dosimetry. Their performance, operational characteristics and limitations, as well as their calibration should be routinely checked to assure satisfactory operation and safe use. This study summarises the results of such type tests and calibrations performed in almost 4750 dosemeters at Ionising Radiation Calibration Laboratory (HIRCL) of Greek Atomic Energy Commission (GAEC). About 13.8% of the pencil type and 4.3% of the electronic dosemeters were found to be out of limits of acceptable performance. For the pencil type dosemeters, the mean calibration factor (CF+/-SD) for high- and low-dose categories was found to be 1.014+/-0.102 (range 0.793-1.458) and 0.995+/-0.059 (range 0.794-1.311), respectively. Of these >85% of them had reproducibility better than 90%, while <1% showed remarkable non-linearity and approximately 10% of them failed to retain the dose reading within the limits after 24 h. For the electronic dosemeters, the mean CF was 1.034+/-0.046 (range 0.967-1.238). The majority of them showed good reproducibility and linearity results while, after irradiation, the dose readings were not shifted through time. The energy response varies with the dosemeter type, reaching in one dosemeter type down to 50%. Both electronic and pencil did not showed electronic equilibrium problems. PMID:17185312

  13. A study of the irradiation temperature coefficient for L-alanine and DL-alanine dosemeters

    International Nuclear Information System (INIS)

    Alanine dosimetry is now well established both as a reference and routine dosemeter for industrial irradiation processing. Accurate dosimetry under the relatively harsh conditions of industrial processing requires a characterisation of the parameters that influence the dosemeter response. The temperature of the dosemeter during irradiation is a difficult quantity to measure so that the accuracy of the temperature coefficient that governs the dosemeter response becomes a critical factor. Numerous publications have reported temperature coefficients for several types of alanine dosemeters. The observed differences in the measured values were commonly attributed to the differences in the polymer binder or the experimental design of the measurement. However, the data demonstrated a consistent difference in the temperature coefficients between L-alanine and DL-alanine. Since there were no commonalities in the dosemeter composition or the measurement methods applied, a clear conclusion is not possible. To resolve this issue, the two isomeric forms of alanine dosemeters were prepared and irradiated in an identical manner. The results indicated that the DL-alanine temperature coefficient is more than 50% higher than the L-alanine temperature coefficient. (authors)

  14. Dosimetric characteristics of a TLD dosemeter with extremities; Caracteristicas dosimetricas de un dosimetro TLD de extremidades

    Energy Technology Data Exchange (ETDEWEB)

    Molina P, D.; Diaz B, E.; Lien V, R. [Centro de Proteccion e Higiene de las Radiaciones, CPHR, Apdo.Postal 6195, Habana 6, CP 10600, Ciudad Habana (Cuba)

    1999-07-01

    It was designed a TLD dosemeter for the monitoring of the extremities. This one consists in a metallic ring with a circular orifice where is arranged a T L detector of LiF: Mg,Ti (Model JR1152C) 5 x 5 x 0.8 mm{sup 3} covered by a polyethylene fine layer. In this work were studied the dosimetric properties of the dosemeter for its application in the dosimetry of extremities for photonic radiation. the results obtained allow conclude that the designed dosemeter can be used for the extremities monitoring. (Author)

  15. A digital interface for preset time or voltage measurements using an ionising radiation dosemeter

    International Nuclear Information System (INIS)

    A digital interface circuit has been built to terminate charge collection measurements made with an ionising radiation dosemeter. A compact portable measurement system has been assembled, comprising a digital voltmeter, a period timer and the digital interface module. Digital signals from both the voltmeter and the timer are compared with separate preset limits, and the dosemeter measurement is terminated when one of these limits is reached. The operation of the dosemeter is outlined, and the interface circuit is described in detail. Modifications to the voltmeter and timer are described, and comprehensive users' instructions are given

  16. A new type active personal dosemeter with a solid state detector

    International Nuclear Information System (INIS)

    We have developed a new type personal dosemeter by using a B-10 doped silicon p-n junction detector with a polyethylene radiator and a polyethylene moderator. The purpose of this study was to develop a real time neutron dosemeter with a nearly flat response in the energy range from thermal to 15 MeV and low angular dependence to the incident neutron direction. The neutron response of the dosemeter was obtained with the Monte Carlo calculation and the monoenergetic neutron experiment in a free air field and also under a condition attached on a phantom

  17. Thermoluminescent dosemeter in a X-ray diffractometer

    International Nuclear Information System (INIS)

    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)

  18. 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.

  19. Characterisation of an electronic radon gas personal dosemeter

    International Nuclear Information System (INIS)

    The monitoring of radon exposure at workplaces is of great importance. Up to now passive measurement systems have been used for the registration of radon gas. Recently an electronic radon gas personal dosemeter came onto the market as an active measurement system for the registration of radon exposure (DOSEman; Sarad GmbH, Dresden, Germany). In this personal monitor, the radon gas diffuses through a membrane into a measurement chamber. A silicon detector system records spectroscopically the alpha decays of the radon gas and of the short-lived progeny 218Po and 214Po gathered onto the detector by an electrical field. In this work the calibration was tested and a proficiency test of this equipment was made. The diffusion behaviour of the radon gas into the measurement chamber, susceptibility to thoron, influence of humidity, accuracy and the detection limit were checked. (author)

  20. Digital Dosemeters - 'ALARA OD' - Personal and Environmental Monitoring Assembly

    International Nuclear Information System (INIS)

    Full text: The importance of prompt dose reporting rises when dose is received within short-time interval or when the radiation source suffers technical failures. New dosimetry concept, where radiation exposure is recognized as a private /or/ group hazard of each person involved in occupational ionizing sources handling, taking into account actual radiation quality of the source, based among other principles, on the principle of establishing the well defined controlled area is introduced. New digital dosemeter device, produced by ALARA Instruments Ltd., measures small occupational doses, including the background. Device is based on ionizing GM tube, a set of modern EEPROM memory chips and Li compound battery set. It operates in two modes and the measurements are continuously performed no matter which mode is on. First mode integrates the dose (including background). If user or dosemeter device enter the higher radiation field area second mode will separately start to measure the dose which is at least two times higher than the surrounding background. The level above which the higher field is considered has to be preprogrammed during the calibration of device. Level depends on the workplace type /or/ environmental conditions where the device will be used. Device is suitable as well for the low level measurements and for the high radiation outputs. When used in the stronger fields, several devices can form a field monitoring system. Device is suitable for the various non-occupational purposes. With some telecommunication electronics and technical improvement, this device is usable as a point (Ort) environmental measuring station. Probe is sensitive to the background radiation and it is fast enough to record any change in normal environmental radiation field, send the data to the central station and raise alarm if necessary. We have built a prototype for environmental monitoring connectable to any kind of telecommunication net. (author)

  1. 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.

  2. 1983 ORNL intercomparison of personnel neutron and gamma dosemeters

    International Nuclear Information System (INIS)

    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

  3. Study of performance of a dosemeter based on thermoluminescent materials for external personnel monitoring

    International Nuclear Information System (INIS)

    The performance of a dosemeter based on thermoluminescent materials, 7 LiF and 6 LiF, was investigated. The verification if the dosemeter response complies with tests recommended by national and international regulatory organizations was performed. Tests of angular and energy dependence, reproducibility, detectability threshold, batch homogeneity and others were carried out and the obtained response is herein presented. Dosemeter response was evaluated in terms of Hp(10). The tests were carried out taking into account the IRD-RT No 001.01/95 and IEC 1066 reporters that gave the guidelines for this evaluation. The obtained response showed that the studied dosemeter complies with the tests and can be employed for individual monitoring. (author)

  4. The calibration of personal dosemeters used for evaluating exposure to solar UV in the workplace.

    Science.gov (United States)

    Sisto, R; Lega, D; Militello, A

    2001-01-01

    In the framework of an epidemiological study regarding the correlation between solar UV radiation exposure and skin pathologies in a population of outdoor workers, the possibility of using polysulphone film personal dosemeters to quantify the Subjects UVB exposure has been evaluated. An original experimental set-up is presented. in a preliminary version, which ill be used both for solar irradiance spectroradiometric measurements and for the reading of personal dosemeters. The polysulphone absorption is similar to the CIE erythemal response curve. Due to UVB radiation exposure, the polysulphone film dosemeters photodegrade with a measrable absorbance change. The absorbance variation after the dosemeter exposure to UV radiation has been correlated to the UVB effective dose. The calibration curve obtained by this method may be particularly useful for the evaluation of small closes. The method will be used to quantify the personal exposure of workers whose exposure conditions are characterised by high variability. PMID:11878432

  5. Development of electronic personal neutron dosemeters: A european co-operation

    International Nuclear Information System (INIS)

    The European Commission recently sponsored an international research and development project, in which three 'active' personal neutron dosemeters were developed. Comparative irradiation experiments showed good results with respect to sensitivity and energy dependence of the response. (author)

  6. The calibration of personal dosemeters used for evaluating exposure to solar UV in the workplace

    International Nuclear Information System (INIS)

    In the framework of an epidemiological study regarding the correlation between solar UV radiation exposure and skin pathologies in a population of outdoor workers, the possibility of using polysulphone film personal dosemeters to quantify the subjects UVB exposure has been evaluated. An original experimental set-up is presented, in a preliminary version, which will be used both for solar irradiance spectroradiometric measurements and for the reading of personal dosemeters. The polysulphone absorption is similar to the CIE erythemal response curve. Due to UVB radiation exposure, the polysulphone film dosemeters photodegrade with a measurable absorbance change. The absorbance variation after the dosemeter exposure to UV radiation has been correlated to the UVB effective dose. The calibration curve obtained by this method may be particularly useful for the evaluation of small doses. The method will be used to quantify the personal exposure of workers whose exposure conditions are characterised by high variability. (author)

  7. The role of phantom parameters on the response of the AEOI Neutriran Albedo Neutron Personnel Dosemeter

    International Nuclear Information System (INIS)

    The response of the AEOI Neutriran Albedo Neutron Personnel Dosemeter (NANPD) which can also be used for other albedo dosemeter types was determined on 18 different phantom configurations. The effects of type, geometry, material, thickness, dosemeter-to-phantom angle in particular with the presence of legs were investigated using a Pu-Be neutron source. It was concluded that the slab phantoms (single or double) and circular and elliptical cylinder phantoms seemed to provide a better response, whereas the ICRU sphere geometry does not seem to be appropriate for the calibration of albedo dosemeters. It is interesting to note that the presence of legs maintains the constancy of the response in a situation when a radiation worker bends down during work. (author)

  8. TL response of LiF: Mg, Cu, P dosemeters in function of the photon energy

    International Nuclear Information System (INIS)

    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 (137 Cs) and 1252 keV (60 Co). The results are presented in function of the sensitivity that the dosemeters showed normalized to gamma radiation of 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. Determination of relevant parameters for the use of electronic dosemeters in pulsed fields of ionising radiation

    International Nuclear Information System (INIS)

    Active electronic dosemeters using counting techniques are used for radioprotection purposes in pulsed radiation fields in X-ray diagnostics or therapy. The disadvantage of the limited maximum measurable dose rate becomes significant in these radiation fields and leads to some negative effects. In this study, a set of relevant parameters for a dosemeter is described, which can be used to decide whether it is applicable in a given radiation field or not. The determination of these relevant parameters-maximum measurable dose rate in the radiation pulse, dead time of the dosemeter, indication per counting event and measurement cycle time-is specified. The results of the first measurements on the determination of these parameters for an electronic personal dosemeter of the type Thermo Fisher Scientific EPD Mk2 are shown. (authors)

  10. The outlook for the application of electronic dosemeters as legal dosimetry

    International Nuclear Information System (INIS)

    This study analyses new trends of a set of 12 electronic personal dosemeters in order to gain an overview of their main advantages and limitations. Physical characteristics and radiological, mechanical and environmental performance were tested according to IEC-61526 Standard requirements. The study highlights the different behaviour of the selected dosemeters. In particular, it is demonstrated that three of the tested devices fulfilled most of the established requirements, whereas another three of them presented important faults. The parameters that need more development are, in general, the response at low energy photon and beta radiation, and the dose rate alarm features. In some cases, mechanical problems as well as interference in the response due to external electromagnetic fields were also found. However, the results of the study foresee a promising future for the application of the newest personal electronic dosemeters as legal personal dosemeters and show the need for internationally agreed technical requirements within the European countries. (author)

  11. Personal neutron dosemeter of the Czech Republic: Review of basic properties, results of recent tests

    Czech Academy of Sciences Publication Activity Database

    Trousil, J.; Spurný, František; Plichta, J.

    2006-01-01

    Roč. 14, 7/8 (2006), s. 246-253. ISSN 1210-7085 Institutional research plan: CEZ:AV0Z10480505 Keywords : detectors * dosemeters * personal dosimetry Subject RIV: DN - Health Impact of the Environment Quality

  12. Conversion factors for the ICRU dose equivalent quantities for calibrating radiation dosemeters

    International Nuclear Information System (INIS)

    Report describing the application of conversion factors for monoenergetic photon radiation and for X and gamma reference radiation used for dosemeter calibration with the aid of spherical or rectangular phantoms (environmental and individual monitoring). (DG)

  13. Recent developments on the CRS PADC (poly-allyl diglycol carbonate) fast neutron personal dosemeter

    International Nuclear Information System (INIS)

    The Dosimetry Laboratory of the Radiation Protection and Safety Centre in Algiers has developed a fast neutron personal dosemeter using a PADC detector. This dosemeter has been type tested in terms of the ICRU calibration quantity, directional dose equivalent at 10 mm, H'(10). This paper gives the results of type test measurements. In addition, some properties of five different PADC materials were investigated in this study. (author)

  14. Dosimetry. Performance requirements and quality of state of the art dosemeters

    International Nuclear Information System (INIS)

    The quality of dose measurements mainly depends on the correct calibration status of the used measuring equipment. In addition - depending on the measuring task - the measuring uncertainty is influenced by other metrological characteristics like energy- and directional response, linearity etc. defining the used dosemeter. Performance requirements of different dosemeter types, defined in national and international standards are reviewed, compared and discussed in this paper. (orig.)

  15. The legal duty of dosemeter calibration, seen from the users' point of view

    International Nuclear Information System (INIS)

    The procedure of official radiation dosemeter calibration, at least that for personal dosemeters and portable ambient dose rate measuring systems, is an established procedure well accepted by the users. As to the calibration of installed ambient dose rate meters, there are many problems still to be solved. One proposal for instance is to just carry through the design qualification tests, and to dispense of calibration and re-calibration of individual systems. (orig./HP)

  16. Quality assurance of personal beta particle dosemeters used for individual monitoring of occupationally exposed persons

    International Nuclear Information System (INIS)

    As a result of investigations and intercomparison measurements organised from 1996 to 1999 by PTB, several types of personal dosemeters, all based on TLD, were selected by the dosimetry services for the measurement of the personal dose equivalent Hp(0.07) in beta and/or photon radiation fields. These dosemeters have now the status of legal personal beta partial-body dosemeters. Workplaces at which beta radiation might significantly contribute to the doses to the extremities are to be found today with increasing frequency in radiation therapy, radiation source production and nuclear power plants. Quality assurance for beta personal dosemeters is stipulated by guidelines for the official dosimetry service and is carried out by way of the intercomparison measurements organised periodically by the PTB. The results are evaluated based on the recommendations of the German Commission on Radiological Protection (SSK). The procedure of these intercomparison measurements will be explained in detail. The experience gained from three series of comparisons with seven types of fingering dosemeters will be described and the results will be presented. The anonymity of the dosemeter types and of the participants in the intercomparison will be preserved. (authors)

  17. Feasibility study of extremity dosemeter based on polyallyl-diglycol-carbonate (CR-39) for neutron exposure

    International Nuclear Information System (INIS)

    In nuclear facilities, some activities such as reprocessing, recycling and production of bare fuel rods expose the workers to mixed neutron-photon fields. For several workplaces, particularly in glove boxes, some workers expose their hands to mixed fields. The mastery of the photon extremity dosimetry is relatively good, whereas the neutron dosimetry still raises difficulties. In this context, the Inst. for Radiological Protection and Nuclear Safety (IRSN) has proposed a study on a passive neutron extremity dosemeter based on chemically etched CR-39 (PADC: polyallyl-diglycol-carbonate), named PN-3, already used in routine practice for whole body dosimetry. This dosemeter is a chip of plastic sensitive to recoil protons. The chemical etching process amplifies the size of the impact. The reading system for tracks counting is composed of a microscope, a video camera and an image analyser. This system is combined with the dose evaluation algorithm. The performance of the dosemeter PN-3 has been largely studied and proved by several laboratories in terms of passive individual neutron dosemeter which is used in routine production by different companies. This study focuses on the sensitivity of the extremity dosemeter, as well as its performance in the function of the level of the neutron energy. The dosemeter was exposed to monoenergetic neutron fields in laboratory conditions and to mixed fields in glove boxes at workplaces. (authors)

  18. Determination of isodose curves in Radiotherapy using an Alanine/ESR dosemeter

    International Nuclear Information System (INIS)

    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 (∼ 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)

  19. Personal neutron dosimetry in nuclear power plants using etched track and albedo thermoluminescence dosemeters

    International Nuclear Information System (INIS)

    Measurement of the personal dose equivalent rates for neutrons is a difficult task because available dosemeters do not provide the required energy response and sensitivity. Furthermore, the available wide calibration spectra recommended by the International Standard Organisation does not reproduce adequately the spectra encountered in practical situations of the nuclear industry. There is a real necessity to characterise the radiation field, in which workers can be exposed, and to calibrate personal dosemeters in order to determine the dose equivalent in these installations. For this reason, we measure the neutron spectrum with our Bonner sphere system and we fold this spectrum with energy-dependent fluence-to-dose conversion coefficients to obtain the reference dose equivalent rate. This reference value is then compared with the personal dosemeter reading to determine a field-specific correction factor. In this paper, we present the values of this field-specific correction factor for etched track and albedo thermoluminescence dosemeters at three measurement locations inside the containment building of the Vandellos II nuclear power plant. We have found that assigning to each personal dosemeter the mean value of the field-specific correction factors of the three measurement locations, allows the evaluation of neutron personal dose equivalent rate with a relative uncertainty of∼25 and 15% for the PADC and albedo dosemeters, respectively. (authors)

  20. Design and characterization of a personal extremity dosemeter for dose evaluation in Hp (0,07)

    International Nuclear Information System (INIS)

    This work describes the development of a personal extremity dosemeter in a finger ring format. The detector element used in this is a LiF:Mg, Ti, chip, manufactured by Harshaw-Bicron (TLD 100). An injection mold was manufactured for the production of a prototype batch of 600 polypropylene rings. The detector element was sealed in the ring using a tool also developed in this research. The ring may be chemically sterilized and its shape does not restrict finger mobility and the use under surgical gloves. The ring has a low cost and, with the exceptional of the chip, is disposable. The dosimetric system in the Thermoluminescent Dosimetry Laboratory of IRD was used for the characterization of the dosimetric properties of the extremity dosemeter. The irradiations were made at the Laboratorio Nacional das Radiacoes Ionizantes/IRD and in the Metrology Department of IPEN.The performance tests for characterization of the extremity dosemeter were accomplished based on the ISO/FDIS 12794 standard, which establishes the performance criteria and tests for determining the performance of thermoluminescence dosemeters to be used for measurement of radiation doses to the extremities due to photons. The operational units used for this personal extremity dosemeter calibration were Hp(0,07). The results show that the system developed for the personal extremity dosemeter fulfill the established requirements in the ISO/FDIS 12792 standard. (author)

  1. Design and test of an albedo personal neutron dosemeter based on PADC detectors

    International Nuclear Information System (INIS)

    Albedo dosemeters, usually based on thermo-luminescence detectors, have been frequently employed in personal neutron dosimetry. Their main advantages are the high sensitivity and the reduced angular dependence, whilst the disadvantages are the sensitivity to photons and the significant energy dependence of the response, which drops dramatically above 0.1 MeV. The present paper proposes an albedo dosemeter based on a planar PADC coupled with a 10B converter. This dosemeter shows good potentials in terms of photon insensitivity, limited angular dependence and high neutron sensitivity. Its use coupled with a dosemeter sensitive in the MeV region, should result in promising dosimetric performances. The response of the PADC based albedo dosemeter was characterized through irradiations in reference neutron fields of 241Am-Be, 252Cf and 252Cf(D2O) and Monte Carlo simulations with the code MCNP-4C. The paper presents the results of the experimental and computational studies and outlines the relevant dosimetric performance of the new albedo dosemeter.

  2. Individual monitoring with official electronic dosemeters in Germany - concepts and reality

    International Nuclear Information System (INIS)

    Full text: Active (electronic) personal dosemeters (APD) are radiometers, which are equipped as active or passive dosimeters. They can directly indicate a dose rate and/or the dose integrated during a certain period (direct-indicating, active electronic personal dosemeters mentioned) or only over a separate reader (direct-selectable, passive electronic personal dosemeters mentioned). A concept is presented for the use of passive or active electronic personal dosemeters in Germany as official dosemeters, e.g. in hospitals. The concept features a net-based approach for secure data communication between readers for passive and active electronic personal dosemeters und the official personal dosimetry monitoring service(s), taking the German policies (StrISchV und RoeV in hospitals) into account. The net-based solution includes a processor controlled interface via TCP/IP connected to the dosimetry reader(s), und reader interfaces, an official interim data bank and all the necessary equipment such as PC, Raid-configuration, USV support, network connection and further details. Investigations have been started to achieve highest-level data manipulation security, data completeness und data correctness. (author)

  3. Biological indicators for radiation exposure. Thymidine concentration in human serum as 'biological dosemeter'?

    International Nuclear Information System (INIS)

    The in vivo test of blood from partial and whole-body irradiated patients revealed no strict differences in radiosensitivity in correlation to the dose, only tendencies for radiation-effects. The serum thymidine concentration appeared to be also dependent on non-investigated factors, such as diseases and previous therapies. Therefore, the suitability of thymidine concentration in blood as a 'biochemical dosimeter' could not be demonstrated. (orig.)

  4. Intercomparison program of personal dosemeters in the Argentine Republic

    International Nuclear Information System (INIS)

    During 1997, under the auspices of the Nuclear Regulatory Authority (ARN), its was held the third exercise of intercomparison of laboratories of personal dosimetry. The dosemeters were irradiated in X-ray beams ISO quality W60, W110, W200 and gamma sources cesium 137 and cobalt 60. The irradiation were performed kerma free in air and in phantom in order to study the capacity to evaluate both conditions. An extent range of doses (low-high) have been given 0.3 mSv- 20mSv in order to determine the operative performance o each laboratory. Over 19 laboratories of Argentina, participated 13 (65%) and finished the intercomparison 12 (60%) of them. The systems of dosimetry detection were based on film and TLD. During this intercomparison as inquiry about several items related with the laboratories have been made. In this work are shown the individual laboratory results of the intercomparison related with the acceptance curve criteria ICRP 60 and 55. (author)

  5. Measurement of doses to aviator pilots using thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    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)

  6. An Active Personal Dosemeter/Spectrometer for Neutrons

    International Nuclear Information System (INIS)

    A prototype of a highly sensitive active personal neutron dosemeter has been developed. It consists of a stack of four silicon detectors sandwiched between layers acting as neutron converters, moderators and absorbers. Its response to quasi-monoenergetic neutrons with energies up to 45 MeV and photons with energies up to 7 MeV has been measured and/or calculated for different angles of incident radiation. The personal dose equivalent determined from the reading obtained in some fields with broad energy distributions deviates by less than 30% from the reference values, both for normal incidence and incidence at 60 deg. to the normal. The detection threshold is about 3 μSv for fast neutrons, 1 μSv for intermediate neutrons and 0.007 μSv for thermal neutrons, even in mixed fields with a photon dose higher by a factor of 20. In addition, the evaluation procedures described give spectral and directional information about the field. (author)

  7. Study of charge reader probes for electret dosemeters

    International Nuclear Information System (INIS)

    Electrets are insulating materials with a quasi-permanent polarization. It can be made from carnauba wax, Teflon and other materials for several applications as transducers, electrophotography, high efficiency air filters and as radiation dosimeters. Electret dosemeters may be used for α, β, γ, X, e- and neutrons radiations with a low construction cost and a simple associated instrumentation. The probe, for charge measurements of the electret dosimeters, is an important device in the experimental set up and its geometry varies according to the geometry of the dosimeter or the scope of the measurements. In this work the development of several probes is described (cylindrical, 1/3 cylindrical and three points probes with different sizes). From the measurements one can demonstrate that cylindrical probe may be used for cylindrical electret geometry, 1/3 cylindrical probe for measurements of directional dependence of the dose and point probe for scanning measurements of plane areas. For high resolution, small point probe may be used and for high sensitivity, the probe-electret distance must be minimized taking account of the Paschen discharge. (author)

  8. Calibration of extremity dosemeters for gamma radiation fields

    International Nuclear Information System (INIS)

    In this work the kerma conversion factor are free in air, dose equivalent H(d,0) are presented, they were obtained theoretical and experimentally in finger and arm for gamma radiation fields. Extremity dosemeters put on surface finger and arm phantom have been irradiated. The finger phantom is a solid cylinder of PMMA polymethylmethacrylate 19 mm diameter and 300 mm height. The arm phantom is a 73 mm external diameter cylinder with PMMA walls 2.5 mm thick fill with water and 300 mm height. The radiation sources were cobalt 60 and cesium 137 from the Regional Center of Reference (CRR) of the National Commission of Atomic Energy (CNEA) and the Nuclear Regulatory Authority (ARN). Also in ISO wide X ray spectra W60, W110 and W200 have been irradiated. The results obtained show a good correlation with those published, they have a difference less than 7%. The factors will be applied to the evaluation of the equivalent doses coming from workers whose main irradiated zone is in the hands. (author)

  9. Calibration of personal dosemeters for X and gamma radiation in front of different phantoms

    International Nuclear Information System (INIS)

    If the directional dose equivalent H'(10) is to become the quantity for calibrating personal dosemeters, some questions as yet still open need to be answered, i.e. the choice of a phantom for the practical calibration procedure together with a suitable set of correction factors. The dose equivalent on the surface of the ICRU sphere can be derived from the dose equivalent on the surface of a phantom different in shape and/or material by applying a phantom-specific and energy-dependent correction factor. However, this has proved unsatisfactory for the calibration of dosemeters which respond differently to the scattered radiation from the phantom. Phantom-specific correction factors are presented and compared with the reponse of selected types of dosemeters exposed on the surface of different phantoms. The different response of dosemeters to scattered radiation is also of interest to the question of the extent to which the reading of a personal dosemeter worn on the trunk will change if it is calibrated on the surface of a phantom in terms of the directional dose equivalent, H'(10), instead of being calibrated in free air in terms of exposure or kerma. (author)

  10. Energy and angular dependence of the personal dosemeter in use at ITN-DPRSN

    International Nuclear Information System (INIS)

    In this paper the characterization of the dosimetry system and of the personal dosemeter in terms of the stability of the reader calibration factors and of the linearity of the response for the 137Cs reference radiation is presented. The energy and angular dependence of the whole body dosemeter are also shown. The energy dependence was determined performing irradiations with the X-ray narrow series beams N30, N40, N60, N80, N100, N120 and with the gamma reference radiations of 137Cs and 60Co [ISO 4037-1, 1996. X and Gamma Reference Radiation for Calibrating Dosemeters and Doserate Meters and for Determining Their Response as a Function of Photon Energy-Part 1: Radiation Characteristics and Production Methods. International Organization for Standardization, Geneva] in terms of Hp(10) incident on the ISO water slab phantom. The angular dependence of the dosemeter was determined for the angles 0 deg., ±20 deg., ±40 deg. and ±60 deg. with normal using the above mentioned radiation fields. All irradiations were performed at the Laboratorio de Metrologia das Radiacoes lonizantes of ITN-DPRSN. The experiments presented in this paper show the thermoluminescence dosimetry (TLD) system is stable and presents a linear behaviour over and extended dose range. The measurements allowed the determination of the energy dependence at normal incidence and of the angular dependence of the dosemeter currently in use. Further studies are being carried out in order to implement correction factors for supralinearity and low energy measurements

  11. Study on the response of indigenously developed CaSO4:Dy phosphor based neutron dosemeter

    International Nuclear Information System (INIS)

    In the present paper we report indigenous development of a neutron sensitive thermoluminescent (TL) dosemeter based on CaSO4:Dy Teflon TL disc. For large scale neutron monitoring of about 15,000 workers, engaged in the nuclear fuel cycle operation, the new dosemeter can be easily incorporated in the present TLD badge system used in personnel monitoring in our country just by a small change in the designing of the badge cassette. The study includes indigenous development of neutron dosemeter, response of the neutron dosemeter in terms of operational quantity to different energies of neutrons under various irradiation conditions. It was found that the thermal neutron sensitivity of the CaSO4:Dy Teflon neutron disc is about one third of TLD-600. However the thermal neutron sensitivity with respect to CaSO4:Dy Teflon gamma disc is about 42 times for in air irradiation and about 84 times for on-phantom irradiation conditions. This newly developed neutron disc can be used as a routine TL dosemeter in the mixed fields of gamma and neutron for neutron energy upto 500 keV for radiation workers engaged in nuclear fuel cycle operation. (author)

  12. The former tests realized to a personal neutron dosemeter based on solid nuclear tracks detector

    International Nuclear Information System (INIS)

    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)

  13. A three element etched track neutron dosemeter with good angular and energy response characteristics

    International Nuclear Information System (INIS)

    A weakness of all single element etched track neutron dosemeters is that the sensitivity falls off too rapidly with increasing angle of incidence. This can lead to significant errors in practical situations. A possible solution is to incorporate in a single dosemeter one or more planar etched track detectors set at an angle to the body surface so that the sensitivity to obliquely incident neutrons is enhanced. The response of a dosemeter in which three planar elements are set in a pyramid structure is investigated. Relationships are developed which allow the response to be estimated for any given direction of incidence and any given angle between face and base of the pyramid. The results indicate that the response is close to that required to measure Hp(10) for any given direction of neutron incidence if the angle between face and base is between 30o and 40o. (author)

  14. Development of new generation-type multi-functional electronic personal dosemeters

    International Nuclear Information System (INIS)

    We have developed advanced new-generation-type small, light, multi-functional electronic personal dosemeters (NRF3 series) using silicon semiconductor radiation detectors for dose management of workers at nuclear power plants and accelerator facilities. These dosemeters are 60 x 78 x 27 mm3 in size and approximately 103 to 115 g in weight, which are capable of measuring personal gamma-ray dose equivalent (NRF30), gamma-ray and neutron dose equivalents (NRF31) and gamma-ray and beta-ray dose equivalents (NRF34). These dosemeters are driven by a lithium battery, CR123A, continuously for about 2000 hours in normal use and can read out the time sequential dose equivalent data via infrared (IR) communication. In addition to IR communication method, NRF31 can read out the dose equivalent data via radio communication using an exclusive radio communication unit. (author)

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

    International Nuclear Information System (INIS)

    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 μSv d-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

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

    DEFF Research Database (Denmark)

    Christensen, P.; Bordy, J.M.; Ambrosi, P.; Bartlett, D.T.; Colgan, T.; Hyvonen, H.; Stadtmann, H.

    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...

  17. From films to thermoluminescence dosemeters: The Greek Atomic Energy Commission experience

    International Nuclear Information System (INIS)

    The personnel dosimetry department of the Greek Atomic Energy Commission (GAEC) assures the individual monitoring of almost 8000 occupationally exposed workers. Thermoluminescence dosimetry system replaced the existing photographic dosimetry system for the individual monitoring with the joint support of IAEA and GAEC. The thermoluminescence dosimetry system consists of two automated readers, one automated irradiator and about 20,000 dosemeters purchased from the Rados Co. The properties of two thermoluminescent materials have been compared: LiF has been chosen for the whole-body dosemeter configuration and Li2B4O7 for the extremities. The technical evaluation of the system has been performed according to the European and IEC standards. The overall uncertainty has been calculated. The existing database system, and the accounting and dispatching procedures have been adapted to the new demands. The system became operational on March 2000, and the official distribution of thermoluminescence dosemeters has begun. (author)

  18. Calibration of personal dosemeters in terms of the ICRU operational quantities

    International Nuclear Information System (INIS)

    The International Commission on Radiological Units and Measurements (ICRU) has defined several new operational quantities for radiation protection purposes. The quantities to be used for personal monitoring are defined at depths in the human body. Because these quantities are impossible to measure directly, the ICRU has recommended that personal dosemeters should be calibrated under simplified conditions on an appropriate phantom, such as the ICRU sphere. The US personal dosimetry accreditation programs make use of a 30 x 30 x 15 cm polymethymethacrylate (PMMA) phantom, therefore it is necessary to relate the response of dosemeters calibrated on this phantom to the ICRU operational quantities. Calculations of the conversion factors to compute dosemeter response in terms of the operational quantities have been performed using the code MCNP. These calculations have also been compared to experimental measurements using thermoluminescent (TLD) detectors

  19. Operational comparison of TLD albedo dosemeters and solid state nuclear tracks detectors in fuel fabrication facilities

    International Nuclear Information System (INIS)

    The authors carried out an operational study that compared the use of TLD albedo dosemeters and solid state nuclear tracks detector in plutonium environments of Japan Nuclear Cycle Development Inst., Tokai Works. A selected group of workers engaged in the fabrication process of MOX (Plutonium-Uranium mixed oxide) fuel wore both TLD albedo dosemeters and solid state nuclear tracks detectors. The TL readings were generally proportional to the counted etch-pits, and thus the dose equivalent results obtained from TLD albedo dosemeter agreed with those from solid state nuclear tracks detector within a factor of 1.5. This result indicates that, in the workplaces of the MOX fuel plants, the neutron spectrum remained almost constant in terms of time and space, and the appropriate range of field-specific correction with spectrum variations was small in albedo dosimetry. (authors)

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

    International Nuclear Information System (INIS)

    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 (6LiF+7LiF) separated by a piece of boron-loaded plastic. For the study, the dosemeters were irradiated in three mixed neutron-gamma fields (thermal neutrons, moderated 241Am-Be and 241Am-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)

  1. Dosemeter readings and effective dose to the cardiologist with protective clothing in a simulated interventional procedure

    International Nuclear Information System (INIS)

    A personal dosemeter issued for individual monitoring is calibrated in terms of personal dose equivalent, usually HP(10). In general it yields a reasonable estimate of effective dose (E) when the exposed person does not wear protective clothing. In interventional cardiology, however, a lead equivalent apron is worn and often a thyroid collar. A correction factor will then be necessary to convert a dosemeter reading to E. To explore this factor an interventional cardiology procedure is simulated based on exposure conditions typical for a modern hospital in the BENELUX area. The dose to the cardiologist is investigated using Monte Carlo simulation of radiation transport. It is concluded that a personal dosemeter may best be worn outside the apron at a central position high on the chest for least dependence on the beam direction. It will overestimate E by roughly a factor of 20 (apron and thyroid collar of 0.25 mm Pb). (authors)

  2. From films to thermoluminescence dosemeters: the Greek Atomic Energy Commission experience.

    Science.gov (United States)

    Carinou, E; Drikos, G; Hourdakis, C; Hyvönen, H; Kamenopoulou, V

    2001-01-01

    The personnel dosimetry department of the Greek Atomic Energy Commission (GAEC) assures the individual monitoring of almost 8000 occupationally exposed workers. Thermoluminescence dosimetry systems will replace the existing photographic dosimetry system for the individual monitoring with the joint support of IAEA and GAEC. The thermoluminescence dosimetry system consists of two automated readers, one automated irradiator and about 20,000 dosemeters purchased from the Rados Co. The properties of two thermoluminescent materials have been compared: LiF has been chosen for the whole-body dosemeter configuration and Li2B4O7 for the extremities. The technical evaluation of the system has been performed according to the European and IEC standards. The overall uncertainty has been calculated. The existing database system, and the accounting and dispatching procedures have been adapted to the new demands. The system became operational on March 2000, and the official distribution of thermoluminescence dosemeters has begun. PMID:11586730

  3. 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).

  4. Estimating effective dose for a cardiac catheterisation procedure with single or double personal dosemeters

    International Nuclear Information System (INIS)

    In most countries of the European Union legislation requires individual determination and registration of the dose to radiological workers exposed to ionising radiation to check whether dose limits are exceeded. To assess stochastic risk, ideally effective dose (E) should be known. In practice, personal dose equivalent [Hp(10)] is used as it can be measured with a personal dosemeter. The dosemeter reading may provide a reasonable assessment of Hp(10), but it may deviate strongly from E, in particular in radiology procedures for medical diagnosis or intervention when protective clothing like lead-equivalent apron and thyroid collar is worn. In the literature various correction factors and algorithms to convert readings of single or dual dosemeters to an estimate of E can be found. An illustrative example of a cardiac catheterisation procedure, in which dose calculations are made by Monte Carlo simulation of radiation transport, shows that such corrections may still yield considerable overestimation. (authors)

  5. Measurements of eye lens doses in interventional cardiology using OSL and electronic dosemeters

    International Nuclear Information System (INIS)

    The purpose of this paper is to test the appropriateness of OSL and electronic dosemeters to estimate eye lens doses at interventional cardiology environment. Using TLD as reference detectors, personal dose equivalent was measured in phantoms and during clinical procedures. For phantom measurements, OSL dose values resulted in an average difference of 215 % vs. TLD. Tests carried out with other electronic dosemeters revealed differences up to ±20 % versus TLD. With dosemeters positioned outside the goggles and when TLD doses were >20 μSv, the average difference OSL vs. TLD was 29 %. Eye lens doses of almost 700 μSv per procedure were measured in two cases out of a sample of 33 measurements in individual clinical procedures, thus showing the risk of high exposure to the lenses of the eye when protection rules are not followed. The differences found between OSL and TLD are acceptable for the purpose and range of doses measured in the survey (authors)

  6. Developing a method and deriving an uncertainty budget for the internal calibration of dosemeters for radiographic equipment

    International Nuclear Information System (INIS)

    Any institution wishing to perform an internal cross calibration of its diagnostic dosemeters should first quantify the uncertainty associated with this to demonstrate that it remains appropriate for the measurements being undertaken. An uncertainty budget for internal cross calibration that covers a range of locally used dosemeters has been derived using the methodology of the International Atomic Energy Agency. The specific internal cross calibration protocol requirements necessary for this uncertainty budget to be valid are discussed. The final quantified uncertainty is 5.31%; this is dominated by the 5% uncertainty associated with the calibration of the reference instrument. The next largest contributions are from differences in temperature and pressure and dosemeter energy dependence. It has been demonstrated that with careful adherence to a well designed internal cross calibration protocol, dosemeters can be calibrated in-house against a calibrated reference dosemeter with very little increase in the associated calibration uncertainty. (paper)

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

    International Nuclear Information System (INIS)

    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 <60 and >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. (authors)

  8. 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. PMID:25213263

  9. External exposure rates measured with TL dosemeters in several regions in Israel

    International Nuclear Information System (INIS)

    Environmental exposure is the main source of background radiation measured by personal dosemeters, and thus influences the minimum occupational dose which can be detected by these devices. Since background levels depend on altitude and local geology we performed a survey of the external exposure at ten different locations in Israel. Indoor exposures due to natural radiation, comprising cosmic, terrestrial and building material components, were determined with the standard personal thermoluminescence LiF dosemeters (Harshaw TLD - I 00). The locations'chosen in this survey are listed in Table I and depicted in Figure 1. They were chosen to represent different altitudes, especially of densely populated areas. The dwellings were selected to represent typical work-places in Israel. Dosemeters were maintained indoors to simulate the actual environment they would normally encounter.Ten TLD - 100 were placed in each dwelling for 60 days or 122 days during the hot summer season. Each dosemeter consisted of a card with three identical chips of 0.38 mm thickness housed in a Harshaw 8814 type card - holder with a transparent window. Fading correction amounted to 6% or 8%.The ten dosemeters in each dwelling were divided into two sub groups: five were placed face up (window side up) and the other five face down, in order to investigate the possible contribution of light to the measured dose. Portable monitors, Bicron micro rem LE, were used to take momentary readings at the same locations. Results of the longer duration measurements (without fading correction) are presented in Table 1. No significant differences could be observed between dosemeters from the two sub groups in each location, implying that ambient light does not have a significant influence on the readings. (authors)

  10. Performance of a coupled albedo/CR-39 personal dosemeter for fast neutron radiation

    International Nuclear Information System (INIS)

    Full text: The individual monitoring of neutron radiation still constitutes a difficult task, due to the wide energy range of the workplace fields and the large variation of the fluence-to-Hp(10) conversion coefficient in such energy interval, which is very difficult to reproduce by the response of a personal dosemeter. Consequently, the overall uncertainty in the dose evaluation procedure is mainly due to the energy dependence of the dosemeter response, which, for commonly employed dosimetric techniques such as the CR-39 and TLD-albedo, is higher than ±50 % in the [0.5 - 4] MeV energy range. This problem can be reduced by using a workplace specific calibration factor, only applicable in those cases where an a priori knowledge of the neutron spectrum is provided. In order to provide accurate dosimetric evaluations in unknown spectra condition, a study was performed by combining the reading of electrochemically etched CR-39 and TLD-albedo dosemeters simultaneously exposed. Irradiation tests on a ISO slab phantom were performed in reference neutron fields at IRSN-Cadarache. A relation was found between the response of the CR-39 or albedo dosemeter and the CR-39/albedo quotient, allowing to correct the reading of each dosemeter. The algorithm was tested in realistic neutron fields of Spanish nuclear power plants, where the energy distribution is known from BSS measurements. The satisfactory results allow proposing the CR-39/TLD-albedo double dosemeter to improve the accuracy of the dose evaluation procedure in the fast neutron individual monitoring. (author)

  11. Test of household salt read by optically stimulated luminescence (OSL) as a personal dosemeter

    International Nuclear Information System (INIS)

    This study has investigated the optically stimulated luminescence (OSL) of household salt and chemically pure NaCl after exposure in different radiation environments. The response relative to thermoluminescent dosimetry using LiF has been investigated to determine if OSL in NaCl can be considered as an alternative to measurements of thermoluminescence in LiF. A selection of staff members at the Diagnostic Centre and the Department of Radiation Physics at Malmoe University Hospital (UMAS) carried small light-tight tubes, 3 mm (diameter) x 27 mm filled with salt. The measurements were accompanied by LiF-TL dosemeters using the regular system for personal dosimetry at UMAS. Similar kits of salt dosemeters were also positioned on the inside walls of a nuclear medicine laboratory and a proton therapy room at the The Svedberg Laboratory in Uppsala. NaCl-OSL dosemeters were also placed in the primary radiation beam of a mammography unit. The OSL in the salt was measured using an OSL reader (Risoe TL/OSL DA 15) at a temperature of 100oC using continuous wave OSL (CW-OSL) with blue LEDs (λ=470 nm). The TL-measurements were made with a TLD reader (Rados Dosacus) using 4.5 mm (diameter) x 0.9 mm LiF: Mg, Ti (Harshaw). Preliminary results show that household salt can be used to measure absorbed doses down to 200 μGy. Measurements also indicate a somewhat higher response relative to LiF-TL dosemeters at low photon energies. The effect may be attributed to the higher atomic number of NaCl (Z=11, 17) compared with LiF (Z=3; 9). We conclude that NaCl-OSL dosemeters appear to be an interesting alternative to TL dosemeters at occupational exposure. (author)

  12. 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...

  13. 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...... systems can comply with these requirements. The emphasis of the experiment was on the dosemeter response as a function of photon energy and angle of incidence of the radiation. The tests were based on the ICRU operational quantities H(p) (0.07) and H(p) (10). All measurements were compared with the true...

  14. Connected TSEE/OSEE readouts of BeO thin-film dosemeters

    International Nuclear Information System (INIS)

    The commonly used TSEE readout for β- or X-irradiated BeO thinfilm dosemeters was complemented by OSEE readouts using blue ( 500 nm) light beams which caused different OSEE decay characteristics. By TSEE a dose range between 10-5 Gy and 10 Gy and by OSEE, a dose range between 10-3 Gy and 104 Gy could be covered. This means that the dose-measuring capacity of BeO thin-film dosemeters linearly comprises 9 orders of magnitude between the low-dose threshold and high-dose saturation. A relation between TSEE and OSEE signals was established by thermal bleaching experiments. (author)

  15. Determination of the dose rapidity of a 90 Sr beta radiation source using thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    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 90 Sr-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)

  16. Sensitivity loss of LiF: Mg,Cu,P thermoluminescence dosemeters caused by oven annealing

    International Nuclear Information System (INIS)

    LiF:Mg,Cu,P is a very sensitive thermoluminescence material that can be used for personal dosimetry in radiology. But if this material is heated too much during annealing or reading it quickly loses its sensitivity. This study shows that an annealing oven in wide use can cause thermal damage to the dosemeters owing to inhomogeneous temperature distribution in the annealing tray. At annealing temperatures >240 deg. C, differences of only 1 deg. C lead to significant losses of sensitivity. Therefore, it is necessary to measure the distribution of temperature in the annealing tray for correct placement of the dosemeters in the tray. (authors)

  17. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  18. Nuclear energy - Radiation protection - Individual thermoluminescence dosemeters for extremities and eyes

    International Nuclear Information System (INIS)

    This International Standard provides performance criteria and tests for determining the performance of thermoluminescence dosemeters intended to be used for the measurement of radiation doses to the eyes and extremities (fingers, and limbs defined as hands, feet, forearms including the elbow, and leg including the patella), for photons from 15 keV to 3 MeV and beta radiation from 0,5 MeV to 3 MeV. It is conditional upon the use of an appropriate reader, procedures and ancillary equipment. It does not cover information access and data processing. This International Standard provides performance criteria and tests for dosemeters intended to measure dose equivalent at depths of 7 mg cm-2 in tissue for fingers and limbs and 300 mg cm-2 in tissue for the eyes, including provision for the use of dosemeters only intended to be used once. Appropriate phantoms and dose conversion coefficients are recommended but others are not precluded. In all cases, performance is assessed under laboratory conditions which may not adequately simulate conditions actually experienced in personal dosimetry. For example, it may be necessary to sterilize dosemeters for medical applications. Therefore, caution is necessary in applying the results of these performance tests in real situations

  19. Effect of some parameters in the response of the Perspex 3042, Lot L amber dosemeters

    International Nuclear Information System (INIS)

    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)

  20. Performance of special extremity dosemeters of BeO in fields of X and gamma radiation

    International Nuclear Information System (INIS)

    A dosimetric system, with a thermoluminescent reproducer and BeO dosemeters incorporated in a discardly metallic support, for using in extremities is tested, in relation theirs mains characteritics: determination of the detectable minimum expousure, linearity of the response of 60Co radiation, thermal fading at 500C and energetic dependence for X-radiation and gamma. (C.G.C.)

  1. EURADOS trial performance test for personal dosemeters for external beta radiation

    International Nuclear Information System (INIS)

    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 (Hp(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 discussed in detail the results obtained from the exercise. In particular, based on the replies to a questionnaire issued to each participant, the results are analysed in relation to important design characteristics of the dosemeters taking part in the test. (author)

  2. Future development of the demands on therapy dosemeters with ionization chambers

    International Nuclear Information System (INIS)

    Only little will change with the introduction of the European internal market with regard to the demands on ionization chamber dosemeters used in radiotherapy, provided that the harmonized standard is aligned with IEC publication 731. Type licences for domestic calibration will be replaced by European Communities licences. (orig.)

  3. The development of a personal dosemeter for use by aircraft crew

    International Nuclear Information System (INIS)

    This paper describes preliminary work to develop a cosmic-radiation dosemeter for use by military aircraft crew. The dosemeter is based on a combination of CR-39 etched-track detectors and TLD-700 thermoluminescent detectors. It is intended that the CR-39 be used to assess the neutron dose, while the TLD-700 is used to assess the photon and charged particle dose. The sensitivity of CR-39 to the neutron component of cosmic radiation was estimated by irradiating samples of the plastic at the CERN-CEC High Energy Reference Field Facility. This facility produced a radiation field with a neutron spectrum resembling that of the neutron component of cosmic radiation a typical airflight altitudes. The response of the CR-39 was linear over the range of doses studied (0.2-6.0 mSv) and there was no significant fading in the six-month period after irradiation. The TLD-700 component of the dosemeter was calibrated using 137Cs gamma rays. The response of the TLD-700 was linear over the range of doses studied (0-1.1 mSv) with no significant fade in the six-month period after irradiation. It was concluded that a combination of CR-39 and TLD-700 detectors would provide an effective cosmic-radiation dosemeter for use by military aircraft crew. (author)

  4. Development and calibration of a neutron personal dosemeter using nuclear tracking solid detectors

    International Nuclear Information System (INIS)

    A personal neutron dosimetry, using two fission track solid detectors, with commercial name CR-39 and Makrofol-DE was developed, calibrated and tested. This dosemeter responds to the neutrons in the thermal, epithermal and fast energy intervals. Also, data from the different development phases are presented

  5. Influence of dosemeter position for the assessment of eye lens dose during interventional cardiology.

    Science.gov (United States)

    Principi, Sara; Ginjaume, Mercè; Duch, Maria Amor; Sánchez, Roberto M; Fernández, Jose M; Vano, Eliseo

    2015-04-01

    The equivalent dose limit for the eye lens for occupational exposure recommended by the ICRP has been reduced to 20 mSv y(-1) averaged over defined periods of 5 y, with no single year exceeding 50 mSv. The compliance with this new requirement could not be easy in some workplace such as interventional radiology and cardiology. The aim of this study is to evaluate different possible approaches in order to have a good estimate of the eye lens dose during interventional procedures. Measurements were performed with an X-ray system Philips Allura FD-10, using a PMMA phantom to simulate the patient scattered radiation and a Rando phantom to simulate the cardiologist. Thermoluminescence (TL) whole-body and TL eye lens dosemeters together with Philips DoseAware active dosemeters were located on different positions of the Rando phantom to estimate the eye lens dose in typical cardiology procedures. The results show that, for the studied conditions, any of the analysed dosemeter positions are suitable for eye lens dose assessment. However, the centre of the thyroid collar and the left ear position provide a better estimate. Furthermore, in practice, improper use of the ceiling-suspended screen can produce partial protection of some parts of the body, and thus large differences between the measured doses and the actual exposure of the eye could arise if the dosemeter is not situated close to the eye. PMID:25514919

  6. Determination of the parameters of traps in thermoluminescent dosemeters of ZrO2: Eu + Ptfe

    International Nuclear Information System (INIS)

    In this work the manufacture of dosemeters in pellets form of ZrO2: Eu + Ptfe is described; which after were exposed to UV radiation (260 nm) were generated the corresponding thermoluminescent curves and in the basis to the properties of symmetry of the curves it was determined the kinetic order using the Chen and the Balarin criteria. (Author)

  7. A measurement of the response to fast neutrons of several materials dosemeters

    International Nuclear Information System (INIS)

    The response to fast neutrons was measured for three types of materials testing dosemeters: fast neutron dosimetry silicon diodes; beryllia, alumina and calcium fluoride TLDs; graphite walled ionisation chambers. The calibrations were made using a 3MW positive ion accelerator. The arrangement of the target, beam monitor and devices is described, and the measured fast neutron sensitivities are presented. (UK)

  8. Compliance of electronic personal neutron dosemeters with the new international standard IEC 61526

    International Nuclear Information System (INIS)

    Full text: The international standard IEC 1323 requires for personal neutron dosemeters a flat personal dose equivalent response within ± 50 % for monoenergetic neutrons in the energy region from 100 keV to 15 MeV and the response for neutrons with energies between thermal and 100 keV had to be stated by the manufacturer. Most of the electronic neutron dosemeters on the market are not able to fulfill this recommendation. Since realistic neutron fields at workplaces have broad spectral distributions and a limited contribution from neutrons with energies between thermal and 100 keV, the new IEC 61526 recommendation allows to replace some of the monoenergetic fields by workplace fields or a broad source having a maximal energy pike, in dose equivalent, close to the energy of the monoenergetic point in place of which it is used, but also gives limits in the energy region from thermal to 100 keV. This work shows results of recent measurements of the personal dose equivalent response for the dosemeters Thermo Electron EPD-N2, Aloka PDM-313 and the prototype dosemeter PTB DOS-2002 and discusses their compliance with respect to the new IEC 61526 standard. (author)

  9. Development of an improved dosemeter for assessments of risk to the eye

    International Nuclear Information System (INIS)

    To develop an improved dosemeter to assess photon and beta exposures of the eye lens, and in response to issues surrounding the preferred values of Hlens to be used for guiding operational radiation protection, a programme of re-optimization of the current PHE thermoluminescence dosemeter has been performed. In particular, refinements of the filter located in front of the sensitive 7LiF:Mg,Cu,P element have been considered, so that the dose response characteristics of the device provide a better and more conservative estimate of risk. The investigation was performed using the Monte Carlo modelling software MCNP5, to produce a final design that featured a filter containing a 9.5 mm diameter polypropylene hemisphere truncated to a maximum thickness of 3.0 mm. The responses of this design in photon and electron fields are presented here, contrasted against those of the existing PHE eye dosemeter, with respect to the operational quantity Hp(3,E,θ) and both current and suggested values for the absorbed dose per fluence risk profile for the lens of the eye. - Highlights: • A programme of re-optimization of the current PHE eye dosemeter has been performed. • A design featuring a truncated hemispherical filter was found to be optimal. • The shape of the filter better resembles the rotational profile of the eye. • Response characteristics depend on the calibration conditions taken to provide the best risk estimate

  10. Influence of dosemeter position for the assessment of eye lens dose during interventional cardiology

    International Nuclear Information System (INIS)

    The equivalent dose limit for the eye lens for occupational exposure recommended by the ICRP has been reduced to 20 mSv y-1 averaged over defined periods of 5 y, with no single year exceeding 50 mSv. The compliance with this new requirement could not be easy in some workplace such as interventional radiology and cardiology. The aim of this study is to evaluate different possible approaches in order to have a good estimate of the eye lens dose during interventional procedures. Measurements were performed with an X-ray system Philips Allura FD-10, using a PMMA phantom to simulate the patient scattered radiation and a Rando phantom to simulate the cardiologist. Thermoluminescence (TL) whole-body and TL eye lens dosemeters together with Philips DoseAware active dosemeters were located on different positions of the Rando phantom to estimate the eye lens dose in typical cardiology procedures. The results show that, for the studied conditions, any of the analysed dosemeter positions are suitable for eye lens dose assessment. However, the centre of the thyroid collar and the left ear position provide a better estimate. Furthermore, in practice, improper use of the ceiling-suspended screen can produce partial protection of some parts of the body, and thus large differences between the measured doses and the actual exposure of the eye could arise if the dosemeter is not situated close to the eye. (authors)

  11. Growth of cerium oxide thin layers for the manufacture of dosemeters and/or irradiation detectors by magnetron RF cathodic sputtering

    International Nuclear Information System (INIS)

    Oxide thin films deposited on silicon substrate are interesting for the manufacture of dosemeters and detectors of gas, humidity, temperature and irradiation. The irradiation dose measurement is required for assessing the risks and advantages of the use of ionizing radiations in fields such as biology, medicine and more generally in all the civil and military nuclear applications. According to literature, cerium oxide seems to be potentially interesting for the manufacture of dosemeters and/or irradiation detectors. The influence of the deposition parameters, such as the inter-electrodes distance, the temperature, the RF power, the work pressure, on the crystalline quality of the CeO2 layers deposited on a silicon (111) substrate by magnetron RF cathodic sputtering has been studied. All these thin films have been characterized by X-ray diffraction and by Raman spectroscopy. At the present time, studies are carried out on 'flash' annealing in order to improve the crystalline state of the thin layers. The aim is to study the influence of gamma and neutrons irradiations on the electric properties of capacities made of CeO2 thin films. (O.M.)

  12. Radiation burden to hands from handling 99Mo-sup(99m)Tc generators measured by UVVVR finger dosemeters

    International Nuclear Information System (INIS)

    The doses to the fingers of seven technicians carrying out elutions of the 99Mo-sup(99m)Tc generators were monitored using LiF RTL dosemeters placed on the volar sides of the thumb, the index and middle fingers, and aluminophosphate glass RTL dosemeters fixed to the dorsal or the volar side of the ring finger. The finger doses corresponded to 0.4 to 1.9% of the annual permissible dose to hands. The maximum value measured in one technician was 14.3 mGy at a whole-body dose of 1.8 mGy as measured by a film dosemeter. (Ha)

  13. Calibration of a special neutron dosemeter based on solid-state track detectors and fission radiators in various neutron fields

    International Nuclear Information System (INIS)

    The calibration of a personnel neutron dosemeter in different neutron fields is described. The badge-like dosemeter contains 5 detectors: polycarbonate foil (10 μm, Makrofol KG), 232Th, natural uranium, natural uranium with boron, and natural uranium with cadmium. Detector sensitivity and calibration factors have been calculated and measured in radiation fields of 252Cf fission neutrons, WWR-S reactor neutrons with and without Cd and Fe shielding, 3-MeV (d,t) generator neutrons, and 238PuBe neutrons. Measurement range and achievable accuracy are discussed from the point of view of applying the dosemeter in routine and emergency uses

  14. Performance of a PADC personal neutron dosemeter at simulated and real workplace fields of the nuclear industry

    International Nuclear Information System (INIS)

    In the framework of the EVIDOS (Evaluation of Individual Dosimetry in Mixed Neutron and Photon Radiation Fields) project, funded by the EC, measurements with PADC personal neutron dosemeters were carried out at several workplace fields of the nuclear industry and at simulated workplace fields. The measured personal neutron dose equivalents of the PADC personal neutron dosemeter are compared with values that were assessed within the EVIDOS project by other partners. The detection limits for different spectra types are given. In cases were the neutron dose was too low to be measured by the PADC personal neutron dosemeter, the response is estimated by convoluting the responses to monoenergetic neutrons with the dose energy distribution measured within EVIDOS. The advantages and limitations of the PADC personal neutron dosemeter are discussed. (authors)

  15. Energy dependence of ulrathin LiF-dosemeters for high energy electrons and high energy X-radiation

    International Nuclear Information System (INIS)

    The energy dependence of ultrathin LiF-dosemeters for high energy electrons (5-40 MeV) and high energy X-radiation (6 MV, 42 MV) is experimentally determined. The experimental values are compared to values calculted earlier by other authors. The influence of the thickness of the dosemeters have been considered by comparison of experimental values for 0.03 mm thick dosemeters and theoretical values for 0.13 mm and 0.38 mm thick ones. Also different commersially available dosemeters have been compared by experiments. It is difficult to draw any other conclutions about the energy dependence than that the variation of the relative responce is within +- 3 percent (2S). However the results seems to be sulficient for clinical applications

  16. Investigation of a new TL individual dosemeter for measuring personal dose equivalent Hp(d) on different phantoms

    International Nuclear Information System (INIS)

    The results obtained with four different types of phantom and pertinent conversion coefficients show that the conversion coefficients for the TE slab phantom are suitable for the calibration of TLD individual dosemeters on a PMMA slab phantom. (Author)

  17. Use of a robotic manipulator in the simulation of the automation of a calibration process of dosemeters

    International Nuclear Information System (INIS)

    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)

  18. Systematic errors in the readings of track etch neutron dosemeters caused by the energy dependence of response

    CERN Document Server

    Tanner, R J; Bartlett, D T; Horwood, N

    1999-01-01

    A study has been performed to assess the extent to which variations in the energy dependence of response of neutron personal dosemeters can cause systematic errors in readings obtained in workplace fields. This involved a detailed determination of the response functions of personal dosemeters used in the UK. These response functions were folded with workplace spectra to ascertain the under- or over-response in workplace fields.

  19. Influence of the PMMA and the ISO slab phantom for calibrating personal dosemeters

    International Nuclear Information System (INIS)

    Wide agreement has been achieved among the main Bodies and Organisations involved in standardisation of radiation protection, related to the operational quantities for personal dosimetry. Since their definition in 1985, several reports have been published to clarify and define the experimental set up to be used for the calibration of dosemeters in terms of the above-mentioned quantities. Among these lines, ICRU 47 has listed five different phantoms that are used for calibration and whose results were accurate, within accepted uncertainties. However, to achieve uniformity in calibration procedures, the 30 cm x 30 cm x 15 cm PMMA slab phantom was recommended. The secondary calibration Laboratory from the Institut de Techniques Energetiques at the Technical University of Catalonia (UPC) agreed with the Spanish Nacional Laboratory to adopt the recommended PMMA phantom but to improve the accuracy of the calibration procedure, by introducing a correction factor for backscatter differences in a PMMA and an ICRU slab phantom. Such corrections were of the order of 8% for the low-energy X-ray qualities. Recently, ISO in ISO 4037-3, has proposed the ISO water slab phantom which consists of a 30 cm x 30 cm x 15 cm water phantom with PMMA walls (front wall 2.5 mm thick). This new phantom could be substituted by the above mentioned PMMA phantom for radiation qualities with mean energy equal or above that of 137Cs. The aim of this work is to compare the influence of both phantoms when calibrating personal dosemeters with photons. A set of four TL personal dosemeters that are used in the UPC personal dosimetry Service and an electronic personal dosemeter (SIEMENS EPD-2) were calibrated in terms of Hp(10) and Hp(0.07) using the two proposed phantoms. Calibration factors for ISO X-ray narrow spectra, 137Cs and 60Co were experimentally obtained for each phantom and compared. In the TL measurements, differences were found to be within TL statistical uncertainty, provided that a

  20. Comparative measurements of external radiation exposure using mobile phones, dental ceramic, household salt and conventional personal dosemeters

    International Nuclear Information System (INIS)

    Because retrospective dosimetry utilises commonly occurring materials and objects, it is particularly useful in cases of large-scale radiation accidents or malevolent acts with radioactive materials where casualties are inflicted on the general public and first emergency responders. The aim of this study was to investigate whether retrospective dosemeters can provide dose estimates with comparable accuracy like conventional personal dosemeters. Using an external source of radiation 137Cs and an anthropomorphic phantom, we simulated serious irradiation of a human body in anterior-posterior and rotational geometries. Retrospective luminescence dosimetry objects, such as mobile phones, dental ceramic and household salt, and conventional personal dosemeters (thermoluminescent and electronic) were fixed to the anthropomorphic phantom. The doses obtained were compared with specific reference values. In most cases, relative deviations between the measured doses and the reference values did not exceed 20%. As the retrospective and conventional dosemeters show no significant differences in laboratory conditions, the retrospective luminescence dosimetry objects represent a very promising tool if handled properly. - Highlights: • A serious external exposure of human body was simulated. • Doses were measured using both retrospective and conventional dosemeters. • Utilised retrospective dosimetry materials were alumina resistors from mobile phones, household salt and dental ceramic. • Doses obtained were compared with reference values. • Both retrospective and conventional dosemeters gave similar results

  1. Dose imaging with gel-dosemeter layers: Optical analysis and dedicated software

    International Nuclear Information System (INIS)

    In radiotherapy involving thermal and epithermal neutrons, the knowledge of dose distributions, with separation of the contribution of each secondary radiation component, is of utmost importance. Layers of Fricke-Xylenol-Orange-infused gel dosemeters give the possibility of achieving such requirements because, owing to the layer-geometry, enriching or depleting the gel matrix of suitable isotopes does not sensibly alter neutron transport. The dosimetry method has been critically re-examined with the aim of improving its suitability to boron neutron capture therapy (BNCT) requirements, as it applies to the protocol of measurement and analysis, the sensitivity of the method and the range of the linearity of the dosemeters. Software has been developed and studied to obtain automatically the images of the various dose components with the established separation procedure. (authors)

  2. Monitoring radiation dose to the hands in nuclear medicine: location of dosemeters

    International Nuclear Information System (INIS)

    The relatively high radiation dose which can be received by the hands of staff in nuclear medicine departments means that in many departments it is necessary to monitor such doses. A convenient method is to use a TLD sachet in a plastic strip around a finger. This study was done to determine whether a dosemeter worn at the base of the middle finger was adequate to monitor the dose to the surface of the whole hand. Dosemeters were worn at the finger tips, finger base and palm of both hands, on two people while preparing and dispensing radiopharmaceuticals, and two others while giving injections using syringe shields. The pattern of distribution of radiation dose to the hands was similar for all workers and for both types of work. A single, convenient site (base of middle finger) may therefore be used for monitoring radiation dose to the hand. (author)

  3. The possibilities of personal albedo neutron dosemeter application at the Slovak cyclotron laboratory

    International Nuclear Information System (INIS)

    In addition to the production of short-lived radioisotopes, the Slovak Cyclotron Laboratory is also engaged in the application of neutron capture therapy, radiotherapy with fast neutrons, and proton therapy. Experiments were carried out where the operating quantities and conversion factors between the neutron fluence and the spatial or personal dose equivalent were determined by Bonner spectrometry over the entire range of energies used, employing a set of moderators. To obtain the requisite dosimetric parameters of the (n,γ) radiation fields, the deconvolution process (statistical regularization) was modified into a rather simple procedure, tractable by using a conventional PC AT. Calibration measurements were employed to obtain the dependence of the sensitivity of albedo dosemeters on the neutron dose ratios in two positions of the dosemeter (on the front and rear sides)

  4. State of the art in thermoluminescent dosimetry using dosemeters with automated read-out

    International Nuclear Information System (INIS)

    In the beginning, the results obtained with automated read-out TLD have been quite disappointing, both for manufacturers and users. In response to this, industry then seeked advice and assistance from those experienced in the practical use of dosemeters, and the development of the second generation of automated TLD has been a common task of manufacturers and purchosers. As a preliminary achievement of development work along this line, a dosemeter has been presented by a Japanese manufacturer, meeting the requirements in quite a satisfactory way. The device is characterized by a frequency of disturbance of -5, a microprocessor for controlling the measuring and control functions, possibility of active input of device parameters and boundary conditions, extensive self-control of operating functions, complete data protection, and thin-film detector technique. Pursuing this line of development, and taking into account future recommentations, automated thermoluminescent dosimetry does seem to be a promising alternative to current measuring techniques in personnel monitoring. (orig./RW)

  5. Characterization of a two-component thermoluminescent albedo dosemeter according to ISO 21909

    International Nuclear Information System (INIS)

    A two-component thermoluminescent albedo neutron monitoring system was developed at Instituto de Radioprotecao e Dosimetria, Brazil. As there is no Brazilian regulation for neutron individual monitoring service, the system was tested according to the ISO 21909 standard. This standard provides performance and test requirements for determining the acceptability of personal neutron dosemeters to be used for the measurement of personal dose equivalent, Hp(10), in neutron fields with energies ranging from thermal to 20 MeV. Up to 40 dosemeters were used in order to accomplish satisfactorily the requirements of some tests. Despite operational difficulties, this albedo system passed all ISO 21909 performance requirements. The results and problems throughout this characterization are discussed in this paper.

  6. Dissolution behaviour of 238U, 234U and 230Th deposited on filters from personal dosemeters

    International Nuclear Information System (INIS)

    Kinetics of dissolution of 238U, 234U and 230Th dust deposited on filters from personal alpha dosemeters was studied by means of a 26-d in vitro dissolution test with a serum ultra-filtrate simulant. Dosemeters had been used by miners at the uranium mine 'Dolni Rozinka' at Rozna, Czech Republic. The sampling flow-rate as declared by the producer is 4 l h-1 and the sampling period is typically 1 month. Studied filters contained 125 ± 6 mBq 238U in equilibrium with 234U and 230Th; no 232Th series nuclides were found. Half-time of rapid dissolution of 1.4 d for 238U and 234U and slow dissolution half-times of 173 and 116 d were found for 238U and 234U, respectively. No detectable dissolution of 230Th was found. (authors)

  7. Determination of the response function for two personal neutron dosemeter designs based on PADC.

    Science.gov (United States)

    Mayer, S; Assenmacher, F; Boschung, M

    2014-10-01

    Since 1998 neutron dosimetry based on PADC (poly allyl diglycol carbonate) is done with a so-called original Paul Scherrer Institute (PSI) design at PSI. The original design (i.e. holder) was later changed. Both designs are optimised for use in workplaces around high-energy accelerators, where the neutron energy spectra are dominated by fast neutrons ranging up to some 100 MeV. In addition to the change of the dosemeter design a new evaluation method based on a microscope scanning technique has been introduced and the etching conditions have been optimised. In the present work, the responses obtained with the original and the new dosemeter designs are compared for fields of radionuclide sources and monoenergetic reference fields using the new evaluation method. The response curves in terms of the personal dose equivalent for normally incident neutrons were built as functions of the incident neutron energy. PMID:24179145

  8. Exposure levels to radiation in a nuclear medicine laboratory: measurements with thermoluminescence dosemeters

    International Nuclear Information System (INIS)

    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 (99m Tc). (Author)

  9. Development of an universal personal dosemeter using semiconductor sensors for mixed radiation fields

    International Nuclear Information System (INIS)

    The objectives of the project are: the development of an electronic personal dosemeter using semiconductors for mixed field radiation monitoring; computer simulation of the optimal design of the filters and converters associated with silicon detectors; and optimization of the silicon detectors. The objective for the reporting period is to develop a portable pocket sized system able to measure both the γ-ray and neutron doses for personal dosimetry. (R.P.) 5 refs., 3 tabs

  10. Determination of the dose index in computerized tomography using thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    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)

  11. Response of dosemeters in the radiation field generated by a TW-class laser system

    International Nuclear Information System (INIS)

    State-of-the-art laser systems are able to generate ionising radiation of significantly high energies by focusing ultra-short and intense pulses onto targets. Thus, measures ensuring the radiation protection of both working personnel and the general public are required. However, commercially available dosemeters are primarily designed for measurement in continuous fields. Therefore, it is important to explore their response to very short pulses. In this study, the responses of dosemeters in a radiation field generated by iodine high-power and Ti:Sapphire laser systems are examined in proton and electron acceleration experiments. Within these experiments, electron bunches of femtosecond pulse duration and 100-MeV energy and proton bunches with sub-nanosecond pulse duration and energy of several megaelectronvolts were generated in single-shot regimes. Responses of typical detectors (TLD, films and electronic personal dosemeter) were analysed and compared. Further, a first attempt was carried out to characterise the radiation field generated by TW-class laser systems. Passive and active dosemeters were used for characterisation of pulsed radiation fields generated by lasers within electron and proton acceleration experiments. Generally, passive, compared with active, systems have the disadvantage of a postponed read-out. However, behaviour of passive systems in the pulsed field seems to be more reliable. Still, results of this study suggest that it might be possible to use active systems under special conditions. Whereas EPDs are not able to reliably detect very short pulses at low repetition rates, their response is promising at higher repetition rates for off-beam locations. Finally, it appears that the definition of the source term of a laser-generated field is not as straightforward as was anticipated. Obtaining a more accurate source term definition for radioprotection purposes would require knowledge and combination of data of at least two sources: generated

  12. Contribution to the development study of a personal fast neutron dosemeter using nuclear emulsion

    International Nuclear Information System (INIS)

    This work deals with the response of a personal neutron dosemeter using nuclear emulsion. The main characteristics of the detector are studied with the help of a computer programme simulating the conditions of the formation of recoil protons tracks recorded by nuclear emulsions. The lecture limits of nuclear emulsions with light microscope and the validity of our computer code are checked by comparing our theoretical values with experimental results

  13. THE RESULTS OF THE EURADOS INTERCOMPARISON IC2014 FOR WHOLE-BODY DOSEMETERS IN PHOTON FIELDS.

    Science.gov (United States)

    Stadtmann, H; Grimbergen, T W M; Figel, M; Romero, A M; McWhan, A F; Gärtner, C

    2016-09-01

    The European Dosimetry Group (EURADOS) first started performing international intercomparisons for whole-body dosemeters for individual monitoring services in 1998. Since 2008, these whole-body intercomparisons have been performed on a regular basis. In this latest intercomparison (IC2014), 96 monitoring services from 35 countries (mostly European) participated with 112 dosimetry systems. Unlike in the previous intercomparisons, the whole registration, communication and data exchange process was handled by a new on-line platform. All dosemeter irradiations were carried out in the Seibersdorf accredited dosimetry laboratory. The irradiation plan consisted of nine irradiation setups with five different photon radiation qualities (S-Cs, S-Co, RQR7, W-80 and W-150) and two different angles of radiation incidence (0° and 60°). The paper describes and analyses the individual results for the personal dose equivalent quantities Hp(10) and if requested, Hp(0.07), for all participating systems and compares these results with the ISO 14146 'trumpet curve' performance criteria. The results show that 100 systems (89 % of all systems) do fulfil the general ISO 14146 performance criteria. This paper gives an overview on the performance of the participating individual monitoring services and the influence of the dosemeter type on the observed response values. PMID:26763903

  14. A portable versatile x- and gamma-ray dosemeter with ditigal display for medical use.

    Science.gov (United States)

    Sankaran, A; Gangadharan, P

    1980-05-01

    A multipurpose dosemeter based on analogue-to-digita (A-d) conversion has been developed using solid state devices, micropower integrated circuits and displays. The A-D converter combines the features of a MOSFET electrometer, a voltage-to-frequency converter, the automatic Townsend balance, LED(LCD) display for exposure, analogue output and has a voltage-measuring accuracy of +/- 0.1% FS +/- 1 digit. The dosemeter, which is designed to measure a wide range of x- and gamma-ray exposure rates (1 mR h-1 to 1000 R min-1) and exposures (1 mR to 1000 R) with a variety of air-equivalent ionisation chambers, is compact, rugged and battery or AC mains powered. It is designed to provide trouble-free performance, easy operation and maintenance and to be independent of climatic conditions. Combining the features of a survey meter, dosemeter and a radioisotope calibrator, it can be fabricated using the facilities locally available in hospitals or universities. PMID:7403264

  15. A portable versatile x-and γ-ray dosemeter with digital display for medical use

    International Nuclear Information System (INIS)

    A multipurpose dosemeter based on analogue-to-digital (A-D) conversion has been developed using solid state devices, micropower integrated circuits and displays. The A-D converter combines the features of a MOSFET electrometer, a voltage-to-frequency converter, the automatic Townsend balance, LED(LCD) display for exposure, analogue output and has a voltage-measuring accuracy of +-O.1% FS+-1 digit. The dosemeter which is designed to measure a wide range of X- and γ-ray exposure rates (1 mRh-1 to 1000 R min-1) and exposures (1 mR to 1000 R) with a variety of air-equivalent ionisation chambers, is compact, rugged and battery or AC mains powered. It is designed to provide trouble-free performance, easy operation and maintenance and to be independent of climatic conditions. Combining the features of a survey meter, dosemeter and a radioisotope calibrator, it can be fabricated using the facilities locally available in hospitals or universities. (author)

  16. Investigation of a BeO-based optically stimulated luminescence dosemeter

    International Nuclear Information System (INIS)

    The optical sensitivity of BeO-based luminophors has been well-known for many years. The optical stimulation of BeO with blue light is most effective. Then the dosemeters emit luminescent light in the ultraviolet-range around 325 nm. Matched on these facts a simple optically stimulated luminescence (OSL) treatment has been developed. Intense blue light-emitting diodes are used for cw-stimulation. A Hamamatsu solar blind photomultiplier detects the OSL-light. Good separation of both spectral ranges by optical filters is very important. The dosemeter has a linear dose response between ∼20 μGy and >10 Gy. It was suggested, that a modification of stimulation conditions would allow measurements down to 1 μGy. Fading, photon energy dependence and reproducibility of OSL-signal correspond well with requirements to clinical and personal dosemeters. In addition, basic questions of the OSL-process in BeO have been investigated. A relevant point of interest was the dependency of the OSL-signal on stimulation power. (authors)

  17. Performance testing of personal dosemeters from eleven dosimetry services in Sweden

    International Nuclear Information System (INIS)

    The Swedish regulation, SSI FS 98:5, requires that radiological workers of category A use dosemeters from an approved personal dosimetry service. The 11 services operating in Sweden at the moment use five different types of dosemeter. All have been tested for their ability to determine Hp(10) and some of them to determine Hp(0.07) according to the European Commission report Radiation Protection 73, EUR 14852, of 1994. The five unique systems have been tested regarding the angular and energy dependence of the response of the dosemeters. The test points for the determination of Hp(10) are all, except one, within the trumpet curve and for the unique systems it is shown that the uncertainty related to angular response at three different energies is within the required ±40% except for the lowest X ray quality 40 kV. The energy dependence dominates over the directional dependence and the choice of radiation quality for calibration is of great importance for the system performance. (author)

  18. A new personal dosemeter for the individual monitoring of exposure to radon gas

    International Nuclear Information System (INIS)

    Rn-Disk dosemeter, a new close-type radon device, is here proposed. Rn-Disk passive monitor consists in a diffusion chamber, made by conductive plastic material (polypropylene enriched with carbon), that holds CR-39 plastics solid-state track detectors (SSNTD). The Rn-Disk passive device (patent pending) has been designed and developed to assess radon exposure received by workers and members of the public. This passive device is an ON/OFF chamber, made of an upper and lower half which snap together during assembly. In particular, it has been designed to exclude radon progeny and dusts entry whilst it allows access of radon gas. The operation principle is based on the revolving cap capability to rotate between 0o and 180o toward its base. This paper includes: a general description of Rn-Disk passive device; preliminary results of several type-tests and qualification tests, conducted in order to define the performances of the Rn-Disk dosemeter, when a CR-39 detector is enclosed in. Emphasis has been given to the investigation of Rn-Disk dosemeter performances in term of sensitivity, level of precision and accuracy of radon measurements, reproducibility, influence of environmental parameters (as temperature, humidity, dusts, etc.), etc. in accordance with ISO standards requirements. (author)

  19. Thermoluminescent response of dosemeters TLD-100 exposed to distinct baker protocols, irradiation and reading

    International Nuclear Information System (INIS)

    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 (ηPCP, γ) 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 ηPCP, γ 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 60Co (ηPCP, γ), varying the lot, the presentation, the one baked and the team reader. When was used the same global procedure values they were obtained for (ηPCP, γ) 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 (ηPCP, γ) 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 (1x1010 p/cm2) 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 results to be 8% greater for the presentation in dosemeters of 1 x 1 x 1 mm3 that for

  20. Tl response of LiF: Mg, Cu, P + PTFE (Mexico) and GR200A (China) dosemeters

    International Nuclear Information System (INIS)

    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 μGy 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)

  1. H p(0.07) photon dosemeters for eye lens dosimetry: Calibration on a rod vs. a slab phantom

    International Nuclear Information System (INIS)

    In recent years, several papers dealing with eye lens dosimetry have been published as epidemiological studies are implying that the induction of cataracts occurs even at eye lens doses of less than 500 mGy. For that reason, the necessity to monitor the eye lens may become more important than it was before. However, only few dosemeters for the appropriate quantity Hp(3) are available. Partial-body dosemeters are usually designed to measure the quantity Hp(0.07) calibrated on a rod phantom representing a finger while a slab phantom much better represents the head. Therefore, in this work it was investigated whether dosemeters designed for the quantity Hp(0.07) calibrated on a rod phantom can also be worn on the head (close to the eyes) and still deliver correct results (Hp(0.07) on a head). For that purpose, different types of partial-body dosemeters from routine use were irradiated at different photon energies on both a rod and a slab phantom. It turned out that their response values are within ±5% independent of the phantom if the quantity value for the respective phantom is used. Thus, partial-body dosemeters designed for the quantity Hp(0.07) calibrated on a rod phantom may be worn on the head and used to monitor the eye lens dose due to photon radiation via the measurement of Hp(0.07) on the head. (authors)

  2. 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

    This paper analyses the influence of the Cerenkov radiation and other noise sources, the so-called stem effect, on radioluminescence (RL) signals generated in optical fibre Al2O3:C dosemeters used in medical dosimetry. The optical fibre dosemeter consists of a sensitive Al2O3:C crystal coupled...

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

    NARCIS (Netherlands)

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

    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

  4. 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.

  5. Performance of a personal neutron dosemeter based on direct ion storage at workplace fields in the nuclear industry

    International Nuclear Information System (INIS)

    In the framework of the EVIDOS project, funded by the EC, measurements were carried out using dosemeters, based on ionisation chambers with direct ion storage (DIS-N), at several workplace fields, namely, at a fuel processing plant, a boiling and a pressurised water reactor, and near transport and storage casks. The measurements and results obtained with the DIS-N in these workplaces, which are representative for the nuclear industry, are described in this study. Different dosemeter configurations of converter and shielding materials were considered. The results are compared with values for personal dose equivalent which were assessed within the EVIDOS project by other partners. The advantages and limitations of the DIS-N dosemeter are discussed. (authors)

  6. Characteristics and performance of the Sunna high dose dosemeter using green photoluminescence and UV absorption readout methods

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.D.; Murphy, M.K.; Tinker, M.R.; Kovacs, A.; McLaughlin, W

    2002-07-01

    Growth in the use of ionising radiation for medical sterilisation and the potential for wide-scale international food irradiation have created the need for robust, mass-producible, inexpensive, and highly accurate radiation dosemeters. The Sunna dosemeter, lithium fluoride injection-moulded in a polyethylene matrix, can be read out using either green photoluminescence or ultraviolet (UV) absorption. The Sunna dosemeter can be mass-produced inexpensively with high precision. Both the photoluminescent and the UV absorption reader are simple and inexpensive. Both methods of analysis display negligible humidity effects, minimal dose rate dependence, acceptable post-irradiation effects, and permit measurements with a precision of nearly 1% 1s. The UV method shows negligible irradiation temperature effects from -30 deg. C to +60 deg. C. The photoluminescence method shows negligible irradiation temperature effects above room temperature for sterilisation dose levels and above. The dosimetry characteristics of these two readout methods are presented along with performance data in commercial sterilisation facilities. (author)

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

    International Nuclear Information System (INIS)

    This paper analyses the influence of the Cerenkov radiation and other noise sources, the so-called stem effect, on radioluminescence (RL) signals generated in optical fibre Al2O3:C dosemeters used in medical dosimetry. The optical fibre dosemeter consists of a sensitive Al2O3:C crystal coupled 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. (authors)

  8. Characteristics and performance of the Sunna high dose dosemeter using green photoluminescence and UV absorption readout methods

    International Nuclear Information System (INIS)

    Growth in the use of ionising radiation for medical sterilisation and the potential for wide-scale international food irradiation have created the need for robust, mass-producible, inexpensive, and highly accurate radiation dosemeters. The Sunna dosemeter, lithium fluoride injection-moulded in a polyethylene matrix, can be read out using either green photoluminescence or ultraviolet (UV) absorption. The Sunna dosemeter can be mass-produced inexpensively with high precision. Both the photoluminescent and the UV absorption reader are simple and inexpensive. Both methods of analysis display negligible humidity effects, minimal dose rate dependence, acceptable post-irradiation effects, and permit measurements with a precision of nearly 1% 1s. The UV method shows negligible irradiation temperature effects from -30 deg. C to +60 deg. C. The photoluminescence method shows negligible irradiation temperature effects above room temperature for sterilisation dose levels and above. The dosimetry characteristics of these two readout methods are presented along with performance data in commercial sterilisation facilities. (author)

  9. Integrating dosemeters for the determination of the radiation exposure of miners exposed to short-lived radon daughter products

    International Nuclear Information System (INIS)

    For the determination of the radiation exposure by short-lived radon daughters integrating measuring instruments are especially suited, because variations of activity concentrations can cause essential errors using short-term dosemeters. At present a measuring instrument based on thermluminescence detectors is used by the SAAS as a stationary area monitor. An electronic personal dosemeter with a semiconductor detector exists as a prototype. Structure and mechanism of both the measuring instruments are described and the feasibility of application in workplaces exposed to radon daughter products are discussed. Proceeding from experience gained in development and application of these instruments an outlook is given for the possibility to develop an applicable universal component system used for standardization of Ra and Ra daughter dosemeters within the CMEA

  10. Estimation of overall uncertainty for various whole body and extremity TLDs, film and CR39 dosemeters

    International Nuclear Information System (INIS)

    Full text: Global Dosimetry Solutions (GDS) is a commercial dosimetry processor for occupational personnel dosimetry. The laboratory offers both film and Harshaw luminescent (TL) dosimeters (TLD) for radiation types that include gamma rays, beta particles and x-rays. Additionally, neutrons are monitored utilizing either TLD's or CR39 track-etch dosemeters. To reduce the probability of introducing random and systematic error into the dosimetry program the laboratory is committed to a strong quality program that provides for: standardization and qualification of procedures including uniform systematic methods, and the proper training of personnel; regular calibration of equipment against recognized standards; provisions for analysis of duplicate samples, including irradiated and unirradiated control dosemeters where appropriate; provisions for control of procurement, storage, and use of all chemicals used in analytical procedures; independent review and checking of calculations, quality control data, and other quality assurance data; routine blind testing of dosemeters; direct inspection of laboratory work and records; provisions for taking corrective actions; retention of quality records for later retrieval. Sources of uncertainty were evaluated for both type A and type B uncertainties, including: GDS Radiological Calibration Facility; J.L. Shepherd Model 81 137Cs Irradiator; Keithly Model 616 electrometer and Xradin Model A3 and A5 ion chambers; NIST Irradiation Facility Sources of Uncertainty; NIST-traceable calibration; ion chamber/electrometer uncertainty; irradiator beam non-uniformity; irradiator shutter; Environmental Factors; Harshaw Reader Repeatability; Panasonic Reader and Badge Reproducibility; Film Densitometer Uncertainty; Film Emulsion/ Batch Variability; TLD Signal Fade; TLD Badge Repeatability; Angular Dependence; Radiation Type/Energy Dependence; CR39 Batch Variability; CR39 Focus Data; CR39 Irradiations; CR39 Foil Repeatability. (author)

  11. Determination of the response function for two personal neutron dosemeter designs based on PADC

    International Nuclear Information System (INIS)

    Since 1998 neutron dosimetry based on PADC (poly allyl diglycol carbonate) is done with a so-called original Paul Scherrer Institute (PSI) design at PSI. The original design (i.e. holder) was later changed. Both designs are optimised for use in workplaces around high-energy accelerators, where the neutron energy spectra are dominated by fast neutrons ranging up to some 100 MeV. In addition to the change of the dosemeter design a new evaluation method based on a microscope scanning technique has been introduced and the etching conditions have been optimised. In the present work, the responses obtained with the original and the new dosemeter designs are compared for fields of radionuclide sources and monoenergetic reference fields using the new evaluation method. The response curves in terms of the personal dose equivalent for normally incident neutrons were built as functions of the incident neutron energy. The time- and cost-intensive establishment of experimentally determined response curves for personal neutron dosemeters is necessary for its dosimetric characterisation and the re-measurement in certain time intervals is obligatory for quality assurance. Therefore, the response of the two PSI designs were measured in reference fields of radionuclide sources and of (quasi-) monoenergetic beams with energies from 24 keV up to 100 MeV. At some energies the differences to the old response curve have been observed. However, in routine dosimetry at workplace fields around high-energy accelerators, where a broad neutron spectrum is faced, these differences are expected to play a minor role and therefore no changes in the routine evaluation procedure of PSI were made. However, work is in progress on folding the new response curves with already measured neutron spectra of workplace fields as well as work is in progress on including the information obtained by the evaluation of the 'thermal' channel from the area under the LiF chip. (authors)

  12. Experience on evaluation of passive neutron dosemeters according to ISO 21909

    International Nuclear Information System (INIS)

    This paper presents experience, found problems and lessons learnt during the evaluations of various TLD and CR-39 passive neutron dosemeters according to ISO 21909. Recommendations for the standard, being currently in revision, are also discussed. The edition 2005 of ISO 21909 is a good first step for having an international standard for testing passive neutron dosimetry systems. However, this standard has many imperfections and this paper tried to bring up some of them. Experience and optimisation of the whole evaluation process according to this standard were also discussed. (author)

  13. Development of an universal personal dosemeter using semiconductor sensors for mixed radiation fields

    International Nuclear Information System (INIS)

    The objectives of the project are: the development of a semiconducting detector system to be used in a personal dosemeter, and the investigation of its dosimetric properties; acquisition of a comprehensive set of data for systematic studies of the response and its energy dependence. The objective for the reporting period is the completion of the investigation of the relevant parameters determining the response and its energy dependence of the Si-diodes covered with compensating filters of different materials. (R.P.) 7 figs

  14. Development of a new electronic personal neutron dosemeter using a CMOS active pixel sensor

    International Nuclear Information System (INIS)

    A CMOS active pixel sensor, originally designed for the tracking of minimum ionising charged particles in high-energy physics, has been recently used for the detection of fast neutrons. Data were taken at the IRSN Cadarache facility with a 241Am-Be ISO source and a polyethylene radiator. A high-intrinsic efficiency (1.2 x 10-3) has been obtained. It is in good agreement with both calculations and a MCNPX Monte Carlo simulation. This experiment paves the way for a fully electronic personal neutron dosemeter. (authors)

  15. Calibration process of survey meters and dosemeters at Standard Dosimetry Laboratory, Nuclear Energy Unit, Malaysia

    International Nuclear Information System (INIS)

    Techniques of calibration and its possible uses are reviewed and discussed. Three main techniques identified are substitution, simultaneous irradiation and inverse square law. The scope of application of each technique is discussed in detail. In addition, tests which are performed on the calibrated dosemeters including energy dependence, angular dependence as well as linearity are explained. For the above purposes, photon radiations from 30 keV to 1250 keV were used. The radiations are obtained by means of an X-ray machine, PHILIPS Model MCN 32, Cs 137 and C60. At the end of the report, several forms tht are required for giving the calibration services are attached. (author)

  16. Overview of active personal dosemeters for individual monitoring in the European Union

    International Nuclear Information System (INIS)

    Full text: In 2001 EURADOS, the working group on harmonization of individual monitoring in Europe and the dissemination of information on new techniques in this field carried out a survey aimed at analyzing the status of the national regulation, use and recent developments in active personal devices (APD) for external individual monitoring. The analysis of the status of APD in 15 EU member states highlighted the extensive use of APD for operational dosimetry, but only very rare recognition for legal dose recording. A catalogue with the main characteristics of the most common APD in Europe and some of the latest developments is presented in this communication. Information has been obtained from the European Radiation Protection and Nuclear Safety Authorities, technical exhibitions in recent scientific meetings and the internet. Information on the type of detector used, physical characteristics, radiological, environmental and mechanical performance, and, when available, dose recording procedure, type testing or the approval document are given in the paper. Developments in this field are currently very rapid and therefore the list of dosemeters cannot be complete, but it is an extensive selection of the main devices available at present. Most devices are calibrated in units of personal dose equivalent, Hp(10) or Hp(10) and Hp(0.07) when they are manufactured for the European market and fulfil the requirements of size and weight according to the IEC 61526 and IEC 61283 Standards. Generally speaking, the overall radiological response of the active personal dosemeters for gamma and beta radiation is comparable to standard passive systems and the environmental performance is satisfactory, especially in the case of the latest developments. Poor performance at low photon energy or in external electromagnetic fields described for earlier dosemeters has now been overcome by several APDs. However, there are still big differences in performance and type testing procedures

  17. Characterization of X-ray beams by attenuation method for personnel dosemeters calibration

    International Nuclear Information System (INIS)

    It has been used the attenuation method to characterize the X rays beams used for calibration of personal dosemeters at Calibration and Dosimetry Laboratory of Peruvian Institute of Nuclear Energy (IPEN). Voltages applied to the X ray tube and the additional filters have been made according to publication ANSI No.13. Half value layer, the homogeneity coefficient and mean energy were determined from attenuation data. Average relative differences of 3, 40 and 4 % respectively were found with respect to values published in ANSI No.13. Also spectral distributions and their resolutions were determined. Relative differences of 16 and 9% respectively were found in comparison with values calculated by the Montecarlo's Method. (author)

  18. Characterisation of N-acetyl-D-glucosamine (NAG) as a lyoluminescent dosemeter

    International Nuclear Information System (INIS)

    Lyoluminescent properties of N-acetyl-D-glucosamine (NAG) were investigated for their suitability as a dosemeter in a lyoluminescent system using sensitised solutions as solvents. Temperature and pH of the solvents were also varied. The detection limit for the system NAG-luminol at 200C using a solvent pH value of 10.6 was of the order of 3 mGy. The reproducibility was within ± 5% for doses of the order of 1 Gy. Measurements with isoluminol showed slightly higher amplification of the LL signal than that obtained with luminol. (author)

  19. Dose characterization in radiation mixed field using thermoluminescent dosemeters at the installation for studies on BNCT

    International Nuclear Information System (INIS)

    This work presents the methodology used for characterization of the absorbed dose due to the gamma radiation (in mixed field of neutrons and gamma), at the installation for studies on BNCT, using thermoluminescent dosemeters. Information is supplied concerning to the obtention of the Victoreen 2800M TL reader parameters, used for performing the TLDs readings, and are presented the construction results of the calibration curves for the TLDs 400 and TLDs 700. From these calibration curves it was determined the absorbed dose due to the gamma radiation in the position of sample irradiation at the installation for the BNCT studies

  20. Study of some characteristic dosimetric of the LIF:Mg, You (JR1152C) for their employment as environmental dosemeter

    International Nuclear Information System (INIS)

    As the interest grows in knowing the effects on the health of the drops dose of natural or artificial radiation, it is made but necessary a system dosimetric able to measure those dose levels accurately. P but of twenty years the dosemeters thermoluminescent (TL) they have constituted a simple and beautiful method for such mensurations. In the work the rehearsals of homogeneity, reproducibility, line lay, detection threshold, auto irradiation, residual, fading and angular dependence are described. The results demonstrate that the dosemeter satisfies the main requirements to be an employee in the environmental monitoring

  1. Photon energy dependence of three fortuitous dosemeters from personal electronic devices, measured by optically stimulated luminescence

    International Nuclear Information System (INIS)

    New data are presented with regard to the relative OSL sensitivity of three different emergency dosemeters irradiated to various photon energies approximately between 48 and 1250 keV using blue excitation light. Investigated components extracted from commonly worn objects include those from USB flash drives (alumina substrate), mobile phones (Ba-rich silicate) and credit cards (chip card module). Several basic properties have been investigated such as the overall radiation sensitivity, the shape of the decay curve and fading of the OSL signal. An increase of the sensitivity for low energies relative to 60Co gamma rays can be observed for the three dosemeters, the increase being very pronounced for the Ba-rich component (factor of 10) and less pronounced for the chip card module (factor of 2). It is concluded that proper dose correction factors for photon energy have to be applied in order to accurately determine the absorbed dose to tissue. The OSL sensitivity to neutron irradiation was investigated as well, but this was found to be less than the gamma sensitivity. (authors)

  2. Neutron dosimetry inside the containment building of Spanish nuclear power plants with PADC based dosemeters

    International Nuclear Information System (INIS)

    The Spanish Nuclear Safety Council (Consejo de Seguridad Nuclear, CSN) recommends performing neutron individual dose assignments at workplaces based on ambient dose equivalent measurements using area monitors and by estimating the amount of time that workers spend in the different monitored environments. In addition, some Spanish nuclear power plants estimate the neutron dose equivalent using albedo thermoluminescence dosemeters (TLD). In the period 2004-2006, our group, together with other research centers, participated in a project, funded by the CSN, with the support of the Spanish Nuclear Power Plants Association (UNESA), to investigate in situ which could be the best practical procedure for individual neutron dose monitoring in nuclear power plants. As part of this survey, several units of the UAB PADC based neutron dosemeter were exposed, on a methacrylate phantom simulating a human body, at four different places inside the containment building of the Asco I nuclear power plant. The influence of different types of calibration neutron fields is analysed and the dose equivalent for each point is estimated.

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

    International Nuclear Information System (INIS)

    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 mm3 in size and ∼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 mm2 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 mm2 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 Univ.. 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. (authors)

  4. Development of New Personal Dosemeter for Low Energy X Rays by Using an Imaging Plate

    International Nuclear Information System (INIS)

    A new personal dosemeter for low energy X rays is being developed using an imaging plate (IP) fabricated by Fuji Film Co. Ltd which has 103 times higher sensitivity than that of the conventional X ray film badge and makes possible the direct reading of PSL (photostimulated luminescence). To investigate the sensitivity with X ray energy, the plate, which was contacted by various filters was exposed on an acrylic phantom and in free air to X rays of effective energies 12, 18, 31, 50, 60, 69, 80, 101 and 120 keV. The filter set was composed of Al, Zn, Cu, Cd, and Pb, and their thicknesses were 0.1 mm to 1.0 mm. The exposure doses were 0.01 to 0.1 mSv. The sensitivity of the IP without filter in free air showed a large dependence on X ray energy. The data with filters were therefore combined and by taking the weighted sum of these data the flat energy response to the dose equivalent, which is necessary for the personal dosemeter, could be obtained. (author)

  5. ENEA extremity dosemeter based on LiF(Mg,Cu,P) to evaluate Hp(3,α)

    International Nuclear Information System (INIS)

    Recent epidemiological studies suggest a rather low-dose threshold (p(d), in paragraph(136), reads that '... a depth d=3 mm has been proposed for the rare case of monitoring the dose to the lens of the eye. In practice, however, Hp(3) has rarely been monitored and Hp(0.07) can be used for the same monitoring purpose... '. As recommended on the EU 'Technical recommendations for monitoring individuals occupationally exposed to external radiation', a test on the ENEA TL extremity dosemeter is herein reported. The results within the actual EU founded Optimization of Radiation protection for Medical staff (ORAMED) Project, whose WP2 is aimed at the quantity Hp(3) and eye lens dosimetry in practice, are taken into account. The paper summarises the main aspects of the study carried out at ENEA-Radiation Protection Inst. (Bologna (Italy)) to provide practical solutions (in the use and the design) to evaluate the response of the ENEA TL extremity dosemeter in terms of Hp(3). (authors)

  6. Studies on the homogeneity of photon fields for contemporary calibration of personal dosemeters on slab phantoms

    International Nuclear Information System (INIS)

    The most recent ICRU recommendations suggest to calibrate photon personal dosemeters on a slab phantom instead of a spherical phantom ads previously proposed. This kind of phantoms due to their geometric characteristics can in principle allow a contemporary calibration of several dosemeters at a time. In this framework, particular attention has to be devoted to the evaluation of the limits of the so-called 'homogeneity area' to be employed. According to the ISO Standard 4037 an homogeneity of the calibration field within 5% (±2.5%) is permissible. A rather detailed analysis on this subject has been therefore carried out using the Monte Carlo code MCNP to evaluate the backscattering profiles on PMMA and water filled PMMA phantoms both for normal and oblique incident radiation. At the same time, some air kerma free in air profiles for seven ISO Narrow and Wide Series beams measured at PTB (Braunschweig Germany) were used to model a more realistic irradiation situation. The calculated data were partially compared with experimental results from other European Laboratories

  7. Dosimetric monitoring by thermoluminescent dosemeters of employers working in ionizing radiation fields

    International Nuclear Information System (INIS)

    Radiation Protection Commission was established in the Ministry of Health and Environment as Regulatory Authority, organizes and supervises all activities related with radiation protection, as the license, inspection, dosemetric personal control, medical examination, radioactive waste management, etc. Actually in our country are exerting some activities, which intend to covert the principal tasks in the field of radiation protection. Such activities are dosemetric personnel control based on TLD, radioactive environmental monitoring, radioactive waste management, calibration of dosemetric equipment's, etc. This paper describes the realization of personnel monitoring by thermoluminescent dosemeters TLD - 100 chips and cards were furnished by IAEA some years ago. Various experiments to determine the dependence of the response of dosemeters versus dose and versus orientation, the fading and lower detectable dose. The personnel monitoring of workers that work in ionizing radiation field were in charge of Institute of Nuclear Physics (INP). Actually in Albania was established the personnel monitoring service for employers of INP, Oncological Centre, Nuclear Medicine Centre and some other nuclear units in Tirana city. On the near future year exists the possibility to extend personnel monitoring for all physicians and technicians of rontgendiagnostic units of Durres, Shkodra, Elbasan cities. (author). 4 refs, 2 tabs

  8. Photon energy dependence of three fortuitous dosemeters from personal electronic devices, measured by optically stimulated luminescence.

    Science.gov (United States)

    Beerten, Koen; Vanhavere, Filip

    2010-08-01

    New data are presented with regard to the relative OSL sensitivity of three different emergency dosemeters irradiated to various photon energies approximately between 48 and 1250 keV using blue excitation light. Investigated components extracted from commonly worn objects include those from USB flash drives (alumina substrate), mobile phones (Ba-rich silicate) and credit cards (chip card module). Several basic properties have been investigated such as the overall radiation sensitivity, the shape of the decay curve and fading of the OSL signal. An increase of the sensitivity for low energies relative to (60)Co gamma rays can be observed for the three dosemeters, the increase being very pronounced for the Ba-rich component (factor of 10) and less pronounced for the chip card module (factor of 2). It is concluded that proper dose correction factors for photon energy have to be applied in order to accurately determine the absorbed dose to tissue. The OSL sensitivity to neutron irradiation was investigated as well, but this was found to be less than the gamma sensitivity. PMID:20304766

  9. Calibration of the IRD two-component TLD albedo neutron dosemeter in some moderated neutron fields

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

    In some stray neutron fields, like those found in practices involving the handling of radionuclide sources, the neutron calibration factor for albedo neutron dosemeter can vary widely compared to the factor for bare sources. This is the case for well logging, which is the area with the largest number of workers exposed to neutrons in Brazil. The companies employ routinely {sup 241}Am-Be neutron sources. The albedo response variation is mainly due to the presence of scattered and moderated neutrons. This paper studies the response variation of the two-component TLD albedo neutron dosemeter used in the neutron individual monitoring service of Instituto de Radioprotecao e Dosimetria, in different radionuclide neutron source beams. The neutron spectra were evaluated applying a Bonner sphere spectrometer with a {sup 6}LiI(Eu) detector in the Brazilian National Metrology Neutron Laboratory. Standard neutron sources of {sup 241}Am-Be and {sup 252}Cf were employed, besides {sup 238}Pu-Be. Measurements were also made with scattered and moderated neutron beams, including {sup 252}Cf(D{sub 2}O) reference spectrum, {sup 241}Am-Be moderated with paraffin and silicone and a thermal neutron flux facility. New neutron calibration factors, as a function of the incident to albedo neutron ratio, were proposed for use in the albedo algorithm for occupational fields where the primary neutron beam is one of those studied sources. (author)

  10. Calibration of the IRD two-component TLD albedo neutron dosemeter in some moderated neutron fields

    International Nuclear Information System (INIS)

    In some stray neutron fields, like those found in practices involving the handling of radionuclide sources, the neutron calibration factor for albedo neutron dosemeter can vary widely compared to the factor for bare sources. This is the case for well logging, which is the area with the largest number of workers exposed to neutrons in Brazil. The companies employ routinely 241Am-Be neutron sources. The albedo response variation is mainly due to the presence of scattered and moderated neutrons. This paper studies the response variation of the two-component TLD albedo neutron dosemeter used in the neutron individual monitoring service of Instituto de Radioprotecao e Dosimetria, in different radionuclide neutron source beams. The neutron spectra were evaluated applying a Bonner sphere spectrometer with a 6LiI(Eu) detector in the Brazilian National Metrology Neutron Laboratory. Standard neutron sources of 241Am-Be and 252Cf were employed, besides 238Pu-Be. Measurements were also made with scattered and moderated neutron beams, including 252Cf(D2O) reference spectrum, 241Am-Be moderated with paraffin and silicone and a thermal neutron flux facility. New neutron calibration factors, as a function of the incident to albedo neutron ratio, were proposed for use in the albedo algorithm for occupational fields where the primary neutron beam is one of those studied sources. (author)

  11. Portable transfer digital dosemeter for beam output measurements with X and gamma rays, electrons and neutrons.

    Science.gov (United States)

    Sankaran, A; Gokarn, R S; Gangadharan, P

    1981-04-01

    This instrument was developed in response to a requirement for an accurate, stable and portable transfer dosemeter for calibration, at therapy dose levels, of equipment used for generating X and gamma rays, electrons and neutrons. The detector is a 0.5 cm3 ionization chamber capable of fitting various wall materials reproducibly at the end of the chamber stem. The measuring system uniquely combines the features of a MOSFET electrometer and an automatic Townsend balance. When used for X, gamma and neutron radiations, the instrument measures the tissue kerma in free air on two ranges: 0.001 - 1.999 Gy (0.1 - 199.9 rad) and 0.01 - 19.99 Gy (1 - 1999 rad) or their exposure equivalents, with autoranging feature when the first range is exceeded. The polarizing voltage (180 V) can be reversed for electron and neutron dosimetry. The dosemeter has a measuring accuracy of +/- 0.2% FS +/- 1 digit and operates on four 1.5 V torchlight cells or on AC mains (200-250 V, 50 - 60 Hz). It utilizes solid state devices, CMOS integrated circuits and displays, and is not affected by RF fields. The instrument is enclosed in a brief-case for portability and is easy to operate and maintain in a hospital. PMID:7225720

  12. Portable transfer digital dosemeter for beam output measurements with X and gamma rays, electrons and neutrons

    International Nuclear Information System (INIS)

    This instrument was developed in response to a requirement for an accurate, stable and portable transfer dosemeter for calibration, at therapy dose levels, of equipment used for generating X and γ rays, electrons and neutrons. The detector is a 0.5 cm3 ionization chamber capable of fitting various wall materials reproducibly at the end of the chamber stem. The measuring system uniquely combines the features of a MOSFET electrometer and an automatic Townsend balance. When used for X, γ and neutron radiations, the instrument measures the tissue kerma in free air on two ranges: 0.001-1.999 Gy(0.1-199.9 rad) and 0.01-19.99 Gy(1-1999 rad) or their exposure equivalents, with autoranging feature when the first range is exceeded. The polarizing voltage (180 V) can be reversed for electron and neutron dosimetry. The dosemeter has a measuring accuracy of +-0.2% FS +-1 digit and operates on four 1.5 V torchlight cells or on AC mains (200-250 V, 50-60 Hz). It utilizes solid state devices, CMOS integrated circuits and displays, and is not affected by RF fields. The instrument is enclosed in a briefcase for portability and is easy to operate and maintain in a hospital. (author)

  13. 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.

  14. Valuation of a CD-96 reader dedicated to quick read-out and archivisation of foil dosemeter absorbance

    International Nuclear Information System (INIS)

    A check of the useful parameters of CD-96 reader is presented. The reader was constructed in the Department of Radioisotope Instruments and Methods of the INCT and dedicated to quick read-out of the foil dosemeter absorbances and for their archivisation. (author)

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

    International Nuclear Information System (INIS)

    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 241Am-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)

  16. The investigation of correspondence of indications of the albedo dosemeter DVGN-01 to personnel irradiation doses in the fields of neutron radiation at the JINR nuclear power installations

    International Nuclear Information System (INIS)

    The calculated results of the research correspondence of the indication of the individual albedo dosemeter DVGN-01 to the individual equivalent dose for neutrons Hp(10) and to the effective dose for neutrons Eeff in the neutron fields at the JINR Nuclear Power Installations (JNPI) at different geometries of irradiations are presented. It has been shown that the correction coefficients are required for specific estimation of doses by the dosemeter. The coefficients were calculated using the energy sensitivity curve of the dosemeter and the known neutron spectra at the JNPI. By using the correction factors the uncertainties of both doses would not exceed the limits given to the personnel according to standards

  17. Study on routines and procedures of calibration of clinical dosemeter on gamma radiation beams at the IPEN-CNEN/SP, Brazil

    International Nuclear Information System (INIS)

    The calibration consists in the comparison of the equipment to be calibrated with other equipment already calibrated by another standard, which means the equipment that will accomplish shall be considered secondary or tertiary, depending on the calibration that will be accomplished. As the clinical dosemeters are used for quality control services in the hospitals, these dosemeters need a reliable measurement precision. Therefore, this work intends to demonstrate the importance of the clinical dosemeter and the calibration, requiring special care face to all clinical set

  18. Photon beam audits for radiation therapy clinics: A pilot mailed dosemeter study in Turkey

    International Nuclear Information System (INIS)

    A thermoluminescent dosemeter (TLD) mailed dose audit programme was performed at five radiotherapy clinics in Turkey. The intercomparison was organised by the Univ. of Wisconsin Radiation Calibration Laboratory (UWRCL), which was responsible for the technical aspects of the study including reference irradiations, distribution, collection and evaluation. The purpose of these audits was to perform an independent dosimetry check of the radiation beams using TLDs sent by mail. Acrylic holders, each with five TLD chips inside and instructions for their irradiation to specified absorbed dose to water of 2 Gy, were mailed to all participating clinics. TLD irradiations were performed with a 6 MV linear accelerator and 60Co photon beams. The deviations from the TL readings of UWRCL were calculated. Discrepancies inside the limits of ±5 % between the participant-stated dose, and the TLD-measured dose were considered acceptable. One out of 10 beams checked was outside this limit, with a difference of 5.8 %. (authors)

  19. Optimal dislocation of thermoluminescent dosemeters in NPP vicinity for detecting external gamma radiation

    International Nuclear Information System (INIS)

    The problem on optimal dislocation of thermoluminescent dosemeters(TLD) in the NPP vicinity for detecting external gamma radiation during normal operation and accidental disposal is solved. To solve this problem, the dose of external gamma radiation in the NPP vicinity during disposal of the noble gas mixture with regard to real weather conditions is calculated. The model of scattering in the Paskwill-Gifford atmosphere and a dose nucleus calculated by Lachti and others is used in calculations. Weather condition data necessary for calculation in different regions of NPP disposition in the European part of the USSR are systematized. To solve problems on the optimization of efficiency control and calculation, the calculational program, which permits to regard arbitrary distribution of population density in NPP surroundings, is

  20. Angular dependence of thermoluminescent dosemeters for gamma and beta radiation in nuclear medicine

    International Nuclear Information System (INIS)

    The gamma and beta radiation sources are widely used in Nuclear Medicine for diagnostic and therapeutic purposes. Workers of these services receive dose of whole body and end due to the activities of the therapeutic dose preparation and testing, administration radiopharmaceuticals and obtention of image. Hands receive higher doses than other parts of the body. Currently the individual monitoring for the gamma radiation is already well established; However, the determination of the dose due to beta radiation still faces some difficulties. In this work it was studied the angular dependence of thermoluminescent dosemeters detectors in beams of gamma and beta radiation. Detectors of CaSO4:Dy + Teflon produced at IPEN - the Brazilian Institute for Nuclear and Energy Researches - were used. The angular dependence was studied varying the angle between 0 and 180 deg. The results obtained proved to be suitable for use in individual monitoring of workers exposed to beta and gamma radiation

  1. Automation of radiation dosimetry using PTW dosemeter and LabVIEWTM

    International Nuclear Information System (INIS)

    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 LabVIEWTM 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 LabVIEWTM as a development tool is extremely convenient to make things easier when software modifications and improvements are needed.

  2. Neutron spectrometry and dosimetry measurement at workplaces for calibration of individual PGP-DIN dosemeters

    International Nuclear Information System (INIS)

    Measurements to determine new coefficients for individual neutron dosimeters PGP-DIN complying with the ICRP 60 recommendations were performed at two workplaces at the CEA of Valduc: a storage room and a plutonium reprocessing plant. Two spectrometry campaigns were performed allowing a better assessment of doses received by operators working at these workplaces. Neutron energy fluence and ambient dose equivalent rate H*(10) distributions were measured as function of neutron energy by using the ROSPEC device and BONNER spheres spectrometer. The radiation field being mixed neutron and gamma, the gamma component was also evaluated: neutron and photon dose-rate meters were used to evaluate the ambient dose rate equivalent. Individual dosemeters were positioned on an ISO water slab phantom. In addition, calculations were performed using the MCNP simulation code for different configurations. (authors)

  3. X-ray beams characterization by the attenuation method for the personal dosemeters calibration

    International Nuclear Information System (INIS)

    The choice of the attenuation method to characterize the x-ray beams used in the calibration of personal dosemeters at the Calibration and Dosimetry Laboratory of the Peruvian Institute of Nuclear Energy (IPEN). Voltages applied to the X-ray tube and the addition of filters have been made according to the publication ANSI No. 13. Half value layer, homogeneity coefficient and mean energy were determined from attenuation data. Average relative differences of 3, 40 and 4% respectively were found with respect to values published in ANSI No. 13. Also spectral distributions and their resolutions were determined. relative differences of 6 and 19% respectively were found in comparison with values calculated by the Monte Carlo Method

  4. Absorbed dose measurements in mammography using Monte Carlo method and ZrO2+PTFE dosemeters

    International Nuclear Information System (INIS)

    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 ZrO2+PTFE thermoluminescent dosemeters, this calculation was completed with calculating the absorbed dose. (author)

  5. Cosmic-radiation dosimetry using electronic personal dosemeter (EPD) at commercial aircraft altitude

    International Nuclear Information System (INIS)

    Electronic Personal Dosemeter (EPD) was examined for effectiveness in cosmic radiation dosimetry at aircraft altitude through the measurements in a Japan-US round trip. The EPD value (Hepd) of individual dose equivalent, penetrating, Hp(10), was considered to be almost equal the deep absorbed dose attributed to electrons at the aircraft altitude. By assuming the fractions and the effective quality factors for other components (muons, protons, and neutrons) based on model-calculation data, an empirical equation to estimate a conservative deep dose-equivalent at 5 cm-tissue depth, H(50), was given as H(50)=3.1 x Hepd. Estimated H(50) values in the international flights were 4.9 μSv h-1 from Tokyo to New York and 3.6 μSv h-1 from Los Angeles to Tokyo. These values agreed well with the predicted values presented by NCRP. (author)

  6. 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.

  7. Application of whole-body personal TL dosemeters in mixed field beta-gamma radiation

    International Nuclear Information System (INIS)

    Application of whole-body personal TL dosemeters based on a high-sensitivity LiF:Mg,Cu,P (MCP-N) in mixed field beta-gamma radiation has been characterised. The measurements were carried out with 90Sr/90Y, 85Kr and 137Cs point sources to calculate the energy response and linearity of the TLD response in a dose range of 0.1-30 mSv. From the result, calibration curves were obtained, enabling the readout of individual dose equivalent Hp(10) from gamma radiation and Hp(0.07) from beta radiation in mixed field beta-gamma. Limitation of the methodology and its application are presented and discussed. (authors)

  8. Automation of radiation dosimetry using PTW dosemeter and LabVIEW™

    Science.gov (United States)

    Weiss, C.; Al-Frouh, K.; Anjak, O.

    2011-10-01

    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™ 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™ as a development tool is extremely convenient to make things easier when software modifications and improvements are needed.

  9. Evaluation of the calibration procedure of active personal dosemeters for interventional radiology.

    Science.gov (United States)

    Bordy, J-M; Daures, J; Clairand, I; Denozière, M; Donadille, L; d'Errico, F; Gouriou, J; Itié, C; Struelens, L

    2008-01-01

    An overview of the use of active personal dosemeters (APD) in interventional radiology is presented. It is based on the work done by the working package 7 of the CONRAD coordinated action supported by the EC within the frame of the 6th FP. This study was done in collaboration with the working package 4 of CONRAD to deal with the calculations required for studying the new calibration facility. The main requirements of the standard for the APD and the difficulties caused by the use of pulsed radiations are presented through the results of an intercomparison organised in a realistic calibration facility similar to the workplace situation in interventional radiology. The main characteristics of this facility are presented. PMID:18757898

  10. Two-dimensional differential calibration method for a neutron dosemeter using a thermal neutron beam.

    Science.gov (United States)

    Matsumoto, Tetsuro; Harano, Hideki; Masuda, Akihiko; Nishiyama, Jun; Matsue, Hideaki; Uritani, Akira; Nunomiya, Tomoya

    2013-08-01

    A new thermal neutron calibration method to experimentally determine the energy response function of a neutron detector using a pulse parallel beam and the time-of-flight (TOF) technique is developed. The calibration method was experimentally demonstrated for a (3)He proportional counter and an electric personal dosemeter using a pulsed thermal neutron beam from the research reactor JRR-3M. The responses of the detectors were successfully obtained as a function of neutron energy. However, detailed information on the detector structure is required to obtain the spatial response distribution for the detector. The authors further propose an improved calibration method obtaining the spatial response distribution using a pulsed narrow beam, the TOF technique and a beam scanning technique. PMID:23509397

  11. Thermoluminescent dosemeters for determining the energy absorbed during X-ray radiography of the vertebral column

    International Nuclear Information System (INIS)

    The dose and absorbed energy during normal diagnostic X-ray of various sections of the vertebral column were determined with LiF-dosemeters in a phantom. The paper describes a method to be used to determine integral doses from the dose measurements. The energy absorbed for one X-ray picture of the vertebral column is between 5 and 30 mJ. Compared to other diagnostical X-rays the quantity of the energy absorbed during X-ray of the vertebral column is rather high and is only reached by X-rays in the pelvic region. The speculations on the rate of incidence of malignent neoplasms on the basis of diagnostical X-ray of the vertebral column reveal a value of 50 per 60 x 106 persons. This value is likely to overestimate the risk, seems, however, to be low in comparison to other risks of every day life (traffic accident, mountainering, etc). (orig./HP)

  12. Mine test of thermoluminescence energy discriminatory track etch personal dosemeters in uranium mines having nearly equal concentrations of radon and thoron daughters

    International Nuclear Information System (INIS)

    Energy discriminatory CEA track etch dosemeters and LiF thermoluminescence dosemeters were used to record the total dose in a uranium mine atmosphere containing both radon daughters and thoron daughters in approximately equal concentrations. In addition, the track etch dosemeters were used to record the individual concentrations of RaA, RaC' and ThC', thereby allowing calculation of the separate radon daughter and thoron daughter working levels. The pump performance of the dosemeters was characterized in terms of durability, stability and sensitivity to attitude, vibration and impact. Grab sampling results taken in the work area were not representative of all of the individual miner exposures because of the strong effect of job function on exposure. (author)

  13. The β-ray energy and angular response of the EYE-D™ eye-lens dosemeter

    International Nuclear Information System (INIS)

    Following the recent ICRP recommendation to decrease the limit of occupational exposure to the eye lens from 150 mSv to 20 mSv/year, a dedicated individual eye-lens dosemeter, EYE-D™, was developed at the IFJ PAN. This dosemeter uses MCP-N (LiF:Mg,Cu,P) thermoluminescent detectors covered with a polyamide capsule and was so far optimized to achieve a flat photon energy and angular response for X-ray exposures typical in interventional radiology. To verify the applicability of this eye-lens dosemeter in external β-ray fields which arise, e.g. in nuclear medicine procedures, we measured and calculated its β-ray energy and angular response. Measurements, applying β-rays from Sr-90/Y-90 isotope, were performed at the Beta Secondary Standard type 2 (BSS 2) in CLOR. Calculations, using the PENELOPE Monte Carlo transport code which simulates coupled electron and photon transport in arbitrary materials, were performed for P-32, K-42 and Sr-90/Y-90 fields to simulate doses received by the eye lens within the human body. PENELOPE Monte Carlo transport code was also used to calculate doses received with EYE-D™ detectors. We found good agreement between the measured and calculated energy and angular responses which confirms the suitability of this dosemeter in assessing Hp(3) to estimate the eye lens. Obtained results and conclusions, however preliminary, conform with current ICRP recommendations when performing individual radiation protection dosimetry in external β-ray fields occurring in nuclear industry and nuclear medicine activities. -- Highlights: •The applicability of EYE-D™ eye-lens dosemeter in external β-ray fields have been investigated. •Measurements and calculations β-ray energy and angular response of EYE-D™ have been performed. •A comparison of calculations results with experimental data is presented. •Obtained results confirmed the suitability of this dosemeter in assessing Hp(3) to estimate the eye lens

  14. 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)

  15. Study of a selection of 10 historical types of dosemeter: variation of the response to Hp(10) with photon energy and geometry of exposure.

    Science.gov (United States)

    Thierry-Chef, I; Pernicka, F; Marshall, M; Cardis, E; Andreo, P

    2002-01-01

    An international collaborative study of cancer risk among workers in the nuclear industry is tinder way to estimate direetly the cancer risk following protracted low-dose exposure to ionising radiation. An essential aspect of this study is the characterisation and quantification of errors in available dose estimates. One major source of errors is dosemeter response in workplace exposure conditions. Little information is available on energy and geometry response for most of the 124 different dosemeters used historically in participating facilities. Experiments were therefore set up to assess this. using 10 dosemeter types representative of those used over time. Results show that the largest errors were associated with the response of early dosemeters to low-energy photon radiation. Good response was found with modern dosemeters. even at low energy. These results are being used to estimate errors in the response for each dosemeter type, used in the participating facilities, so that these can be taken into account in the estimates of cancer risk. PMID:12408486

  16. Practical consequences for the use of a personal dosemeter for fast neutrons at high-energy accelerators based on PADC detectors exposed up to one year

    International Nuclear Information System (INIS)

    Since 1998, Paul Scherrer Institut has employed the routine use of a personal neutron dosimetry system based on chemically etched PADC (poly allyl diglycol carbonate) detectors and automatic track counting. In 2004, a new concept for individual monitoring at high-energy accelerators was implemented. In this concept the photon dosemeter of a combined photon/neutron dosemeter is evaluated monthly. The neutron dosemeter is only evaluated if the personal photon dose exceeds 2 mSv, or if the exposition period of the neutron dosemeter exceeds one year. Significant consequences for the evaluation of the neutron dosemeter in the dosimetry service were evidenced in the new concept. The wearing period of the neutron dosemeter can range from 1 to 12 months, potentially longer. Therefore, the long-term behavior of background track density and variation of response to Am-Be within 17 months was studied. The effects of 'fading' and 'aging' that influence the response of PADC detectors are determined. The application of an algorithm for neutron dose calculation takes into account long-term behavior and is described. Furthermore, repeated field calibrations were performed at the CERN-EU high-energy reference field (CERF) facility.

  17. Comparison of neutron dose quantities and instrument and dosemeter readings at representative locations in an MOX fuel fabrication plant

    CERN Document Server

    Bartlett, D T; Tanner, R J; Haley, R M; Cooper, A J

    2002-01-01

    The relationships between operational and protection quantities, and values of personal dosemeter and instrument readings have been determined for a recently designed MOX fuel fabrication plant. The relationships between the quantities, and the readings of personal dosemeters are sensitive to both the energy and direction distribution of neutron fluence. The energy distributions were calculated using the Monte Carlo code MCBEND. The direction distribution was addressed by calculating independently, spectral components for which the direction distribution could be reasonably assumed. At representative locations, and for assumed worker orientations, the radiation field is analysed as having, in general, three components--a direct, unidirectional component from the nearest identified discrete source, which is considered incident A-P, several unidirectional components from other such sources which are treated as a rotational component and a scattered isotropic component. The calculated spectra were folded with co...

  18. Relative thermoluminescent efficiencies proton/gamma and helium/gamma of high temperature peaks in TLD-100 dosemeters

    International Nuclear Information System (INIS)

    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)

  19. New ICRU quantities for the environmental and individual monitoring. Standardization of individual dosemeters by using external beams of photon radiation

    International Nuclear Information System (INIS)

    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

  20. The routine calibration in terms of the new ICRU quantities of personal dosemeters to be worn on the trunk

    International Nuclear Information System (INIS)

    A brief article describes the routine calibration of personal dosemeters in terms of the phantom quantities directional dose equivalent at 0.07 mm, H' (0.07) and at 10 mm, H' (10) for which internationally recommended conversion coefficients from air kerma or neutron fluence are available. These quantities are the calibration quantities for the measurement of individual dose equivalent, superficial, and individual dose equivalent, penetrating respectively. (U.K.)

  1. Performance of a personal neutron dosemeter based on direct ion storage at workplace fields in the nuclear industry

    International Nuclear Information System (INIS)

    Full text: Devices for personal dosimetry in neutron or mixed neutron-photon fields are still far less established than systems for photon radiation only. The DIS-N dosemeter based on ionization chambers with Direct Ion Storage developed by RADOS has the potential to contribute to the improvement of this situation. A double-chamber system allows for differential readings to separate the neutron from the photon dose. The sensitivity to neutrons can be altered by using different converter materials, i.e. polyethylene containing lithium or the tissue equivalent material A-150 containing boron. The dose response can further be modified by surrounding and thus shielding the detectors with additional material mainly to reduce the sensitivity to thermal neutrons. In the framework of the EVIDOS project, funded by the EC, measurements with DIS-N dosemeters were carried out at several workplace fields, namely at a fuel processing plant, a boiling and a pressurized water reactor and near transport and storage casks. The measurements and results obtained with the DIS-N in these workplaces, which are representative for the nuclear industry, are described. Different configurations of converter and shielding materials were considered. The results are compared with reference values for personal dose equivalent which were assessed within the EVIDOS project by other partners. The advantages and limitations of the DIS-N dosemeter are discussed. (author)

  2. Estimating the uncertainty in measurement of occupational exposure with personal dosemeters

    International Nuclear Information System (INIS)

    Full text: In the 1990 Recommendations of the ICRP it is stated that an uncertainty of a factor 1.5 in either direction 'will not be unusual' in a dose measured under workplace conditions. In many documents like the EU Technical recommendations, the IAEA Safety Guides and papers in scientific journals, this statement is understood to be a starting point for developing type-test criteria and criteria for approval of dosimetric systems. And, although meant to refer to effective dose it is usually understood to refer to personal dose equivalent as well. When using a personal dosemeter, the quantity to be measured, personal dose equivalent, is derived from a number of input quantities such as light output of one or more TLDs or densities of areas on a film, sensitivity of the detection material, properties of the evaluating equipment and dose due to background radiation. Each of these input quantities is the result of a measurement that is inexact and thus resulting in an inexact value for the dose. In cases where the transformation of the raw measurements into the quantity to be estimated, measurand, only involves linear transformations and the distributions of the errors in the input quantities are Gaussian or at least symmetrical and Gausslike, then the uncertainty in the measurand can more or less reliably be derived from the uncertainties in the input quantities using the familiar 'general law of error propagation'. In cases where the evaluation involves non-linear transformations and/or the probability distributions of the input quantities are not well approximated by Gaussian distributions then it is far from obvious that the familiar techniques will result in a realistic estimate of the uncertainty in the dose. This paper presents a method using Monte Carlo techniques that does not depend on the validity of the general law of error propagation. The method is based on the 'Guide to the Expression of Uncertainty in Measurement' and the 'Supplement 1: Numerical

  3. Development of a extremity thermoluminescence dosemeter for photon dose equivalent assessment

    International Nuclear Information System (INIS)

    An extremely thermoluminescence dosimeter, to be used when the extremity may become the limiting organ, based on CaSO4:Dy pellet was developed to be worn as wristlet by technicians who work with unsealed sources or handle radioactive materials. This system permits photon dose equivalent assessment as well as the effective energy determination. Such dosemeter has to be worn in addition to a whole-body dosemeter. The system consists of two pieces of polyethylene with dimensions of 40 mm x 20 mm x 10 mm that can be superimposed and three discs of CaSO4:Dy plus Teflon (PTFE), as sensitive material, between different filters. The detectors are produced by the Dosimetric Materials Laboratory of IPEN and have diameter of 6.0 mm and a thickness of 0.8 mm. One detector is placed between plastic filters of 3.0 mm thickness that guarantees electronic equilibrium for 60Co gamma rays. Another detector is located between 1.0 mm thick lead filters plus 3.0 mm plastic filters. A third detector is sandwiched between filters of lead 0.8 mm thick with a central hole of 2.0 mm diameter and plastic filters of 3.0 mm thickness. The detectors are sealed in a plastic film 20 mg.cm-2 thick. All TL detectors are in contact with filters. The filter area is a little larger than the TL detector. The validation of the proposed dosimetric system was performed for 60Co gamma doses between 0.1 and 200 mGy. In this range the relationship dose-response is linear. The energy response of the dosimetric system was evaluated for an energy range between 30 and 662 keV. The maximum, relative to 60Co, energy dependence TL response is observed at 31.2 keV (factor 10.2). To obtain the dose equivalent and the effective energy from the correlation between the three TL readings was developed an algorithm. Taking into account the results obtained in simulated laboratory comparisons, better than ±5%, we conclude that the proposed dosimetric system agrees with the requirements for its application as extremity

  4. Evaluation of the directional dose equivalent H,(0.07) for ring dosemeters

    International Nuclear Information System (INIS)

    The personnel dosimetry laboratory (LDP) of the Metrology department received an user's of radiation beta application that incidentally had irradiated 14 couples of ring dosemeters for extremities of the type TLD-100 given by the LDP. This sample of 14 couples of rings tentatively it was irradiated in the months of July-August of the year 2004, and he requested in an expedite way the evaluation of the received dose equivalent. The LSCD builds two calibration curves in terms of the directional dose equivalent H'(0.07) using two sources patterns of 90 Sr-90 Y for beta radiation: one of 74 MBq and another of 1850 MBq with traceability to the PTB. The first curve in the interval of 0 to 5 mSv, the second in the range of 5 to 50 mSv, taking into account effects by positioned of the rings in the phantom. Both calibration curves were validated by adjustment lack, symmetry of residuals and normality of the same ones. It is evaluated and analyzing the H'(0.007) for these 14 couples of rings using the Tukey test of media of a single road. It was found that the H, its could be classified in 4 groups, and that the probability that its has irradiated in a random way it was smaller to the level at α = 0.05. (Author)

  5. Cosmic-radiation dosimetry using electronic personal dosemeter (EPD) at commercial aircraft altitude

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, Hiroshi; Fujitaka, Kazunobu [National Inst. of Radiological Sciences, Chiba (Japan). International Space Radiation Lab.

    2000-02-01

    Electronic Personal Dosemeter (EPD) was examined for effectiveness in cosmic radiation dosimetry at aircraft altitude through the measurements in a Japan-US round trip. The EPD value (H{sub epd}) of individual dose equivalent, penetrating, H{sub p}(10), was considered to be almost equal the deep absorbed dose attributed to electrons at the aircraft altitude. By assuming the fractions and the effective quality factors for other components (muons, protons, and neutrons) based on model-calculation data, an empirical equation to estimate a conservative deep dose-equivalent at 5 cm-tissue depth, H(50), was given as H(50)=3.1 x H{sub epd}. Estimated H(50) values in the international flights were 4.9 {mu}Sv h{sup -1} from Tokyo to New York and 3.6 {mu}Sv h{sup -1} from Los Angeles to Tokyo. These values agreed well with the predicted values presented by NCRP. (author)

  6. The influence of time-temperature on the behaviour of TLD-100 as personal dosemeters

    International Nuclear Information System (INIS)

    Since 1965, the survey of individual exposure for the people working in the medical field is carried out within the Institute of Hygiene and Public Health, by a central service belonging to the Romanian Ministry of Health. During this period 6500 persons per month were monitored, using film-badges. The relative low sensitivity of film dosemeters lead to a decrease of confidence in this old system. Furthermore, the film badges do not have appropriate filters for measuring the personal equivalent doses Hp(10) and Hp(0.07), as are the new recommendations of ICRP and IAEA. These facts made clear there is a necessity of changing this type of monitoring system with another one, having a higher sensitivity and allowing the measurement of personal equivalent doses Hp(10) and Hp(0.07). The decision was to switch to a TL dosimetry system, namely the Harshaw 6600 System. The performances of this new system have to be checked by the TL Dosimetry Group, at the Institute of Hygiene and Public Health, before being officially accepted as the new individual dosimetry system. The paper presents the results of some of the test performed on the TLD-100 chips, concerning the influence of the heating rate and pre-heat temperature and duration (the time-temperature profiles) and the fading of the detectors. (author)

  7. Use of active personal dosemeters in interventional radiology and cardiology: Tests in hospitals – ORAMED project

    International Nuclear Information System (INIS)

    Although active personal dosemeters (APDs) are not used quite often in hospital environments, the possibility to assess the dose and/or dose rate in real time is particularly interesting in interventional radiology and cardiology (IR/IC) since operators can receive relatively high doses while standing close to the primary radiation field. A study concerning the optimization of the use of APDs in IR/IC was performed in the framework of the ORAMED project, a Collaborative Project (2008–2011) supported by the European Commission within its 7th Framework Program. This paper reports on tests performed with APDs on phantoms using an X-ray facility in a hospital environment and APDs worn by interventionalists during routine practice in different European hospitals. The behaviour of the APDs is more satisfactory in hospitals than in laboratories with respect to the influence of the tube peak high voltage and pulse width, because the APDs are tested in scattered fields with dose equivalent rates generally lower than 1 Sv.h−1. .

  8. Active personal dosemeters in interventional radiology: Tests in laboratory conditions and in hospitals

    International Nuclear Information System (INIS)

    The work package 3 of the ORAMED project, Collaborative Project (2008-11) supported by the European Commission within its seventh Framework Programme, is focused on the optimisation of the use of active personal dosemeters (APDs) in interventional radiology and cardiology (IR/IC). Indeed, a lack of appropriate APD devices is identified for these specific fields. Few devices can detect low-energy X rays (20-100 keV), and none of them are specifically designed for working in pulsed radiation fields. The work presented in this paper consists in studying the behaviour of some selected APDs deemed suitable for application in IR/IC. For this purpose, measurements under laboratory conditions, both with continuous and pulsed X-ray beams, and tests in real conditions on site in different European hospitals were performed. This study highlights the limitations of APDs for this application and the need of improving the APD technology so as to fulfil all needs in the IR/IC field. (authors)

  9. Performance of CVD diamond as an optically and thermally stimulated luminescence dosemeter

    International Nuclear Information System (INIS)

    Diamond is a material with extreme physical properties. Its radiation hardness, chemical inertness and tissue equivalence qualify it as an ideal material for radiation dosimetry. In the present work, the optically stimulated luminescence (OSL) and thermoluminescence (TL) characteristics of a 10 μm thick CVD diamond (polycrystalline diamond films prepared by chemical vapor deposition) film were studied in order to test its performance as a beta radiation dosemeter. The TL response is composed of four main TL glow peaks; two of these are in the range of 150-200 deg. C and two additional peaks in the 250-400 deg. C temperature range. The integrated TL as a function of radiation dose is linear up to 100 Gy and increases with increasing dose exposure. The dose dependence of the integrated OSL exhibits a similar behavior. The observed OSL/TL behavior for the CVD diamond film clearly demonstrate its capability for applications in radiation dosimetry with special relevance in medical dosimetry owing to the diamond's intrinsic material properties. (authors)

  10. Investigations of the luminescence of phosphate glasses with respect to their application as solid dosemeters

    International Nuclear Information System (INIS)

    A comprehensive presentation of the luminescent properties of phosphate glass is worked out. The extensive investigations show an essential enlargement of the knowledge on the luminescence of phosphate glass existing hitherto. These results form the basis for a detailed discussion of the luminescence mechanism. By applying additional results of measurements concerning optical and paramagnetic absorption, enabling the access to the atomic effect, propositions were developed for models of absorption, excitation and luminous centers relevant for dosimetry for which Ag++ was found to be the constituent determining the centers. The interpretation of the luminescence phenomena within the frame of these models leads to considerable corrections on the existing concepts. At the same time the comparability of Ag-doped phosphate glasses and alkali halogenides is shown with respect to their luminescence behaviour, and with it an argument for the existence of crystal-like short-order regions in the amorphous glass is provided. This result serves as a basis for a discussion of the centers in the band model. Further investigations dealt with the quantities of influence for the practical application of the dosemeter. By interpretation of these results explanations are given for the effect of irradiation and evaluation temperatures, of LET, the dose, and UV light on the measuring signal. The phenomenon of 'pre-dose', for which especially surface effects have been detected as cause, is discussed under the aspect of a boundary layer theory. (orig./HP)

  11. Cosmic radiation protection dosimetry using an electronic personal dosemeter (Siemens EPD) on selected international flights

    International Nuclear Information System (INIS)

    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. (author)

  12. The implementation in routine of the ENEA new personal photon dosemeter

    International Nuclear Information System (INIS)

    The ENEA photon dosemeter, introduced in 1995, consisting of two differently filtrated LiF(Mg,Cu,P) detectors, has been modified recently. The ABS (acrylonitrile butadiene styrene) plastic support has been replaced by a new aluminium card supporting the same two detectors (LiF(Mg,Cu,P) GR200). The new card, fully developed at the ENEA-Radiation Protection Inst. (which is going to be patented), can now be processed through a Harshaw Model 6600 Automated TLD Reader, a hot gas reader. This paper reports the results of the individual calibration of ∼60,000 LiF(Mg,Cu,P) GR200 detectors inserted on the new aluminium cards. Before the implementation in routine of the new cards, the reader has been characterised. Steps and tests to be made to use the card in routine (i.e. reader stability, linearity, reproducibility, etc.) are reported. The whole dosimetric system now combines the very good performances of the Harshaw Model 6600 reader and that of LiF(Mg,Cu,P) thermoluminescent material. (authors)

  13. Thermoluminescent and optical processes in alkaline halogenides dosemeters contaminated with Europium

    International Nuclear Information System (INIS)

    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)

  14. Biological dosimetry, scopes and limitations

    International Nuclear Information System (INIS)

    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)

  15. Utilization of thermoluminescent dosemeters for determination of exposure or absorbed dose in a radiation gamma or X radiation field with unknown spectral distribution

    International Nuclear Information System (INIS)

    Having in view the choice of the best pair of dosemeters to be used in the 'Tandem' method, the main response characteristics of LiF:Mg, Ti, Li2B4O7:Mn, CaSO4Dy, CaF2:Mn and CaF2:Dy thermoluminescent dosemeters and also some critical parameters in their calibration and evaluation processes were studied. Three different physical forms of TLD's were investigated: hot pressed chips, disc teflon dosemeters and glass mini TLD's. Their calibration factors were obtained for the energy of Cobalt-60 gamma rays. Their energy dependences normalized to 60Co radiation were determined using spectral width as parameter. 'Tandens' formed by all TLD's evaluated were compaired. (E.G.)

  16. Effect of the energy dependence of response of neutron personal dosemeters routinely used in the UK on the accuracy of dose estimation

    CERN Document Server

    Tanner, R J; Thomas, D J

    2002-01-01

    A large set of neutron energy distributions have been classified by workplace to provide a guide to the neutron fields to which workers in particular industries are likely to be exposed. These have been combined (folded) with the results of a major programme of neutron personal dosemeter response function measurements, to provide results for the systematic errors that those dosemeters would give in workplaces. Data for neutron doses recorded for UK classified workers have been taken from the CIDI tables, and related to the results from the folding process. It has hence been possible to draw conclusions about the probable systematic errors that result from the use of the currently available neutron personal dosemeters, which have inherent problems associated with their energy dependence of response.

  17. A combined dosemeter for passive, long-term integration measurement of radon and its short-lived decay products in air

    International Nuclear Information System (INIS)

    Natural radiation exposure of man, and especially the radiation exposure of professionally exposed persons, is predominantly caused by radon (Rn), a gas occurring naturally, and its short-lived decay products (RnDPs). Compared to the short-lived RnDPs, the inhalative radiation load caused by the radon gas itself is smaller in general by more than one order of magnitude. Because of this, and because of the fact that it is not known how much time is spent by professionaly exposed persons and persons from the general population in their spheres of life respectively of work, the development of a personnel dosemeter permitting to establish directly the dose-determining content of RnDPs in air is pre-eminent in order to establish the real, individual radiation exposure of persons, BfS, in cooperation with ULS, has developed, calibrated and tested under different conditions a passive personnel/area dosemeter for combined determination of the RnDP content and Rn concentration in atmosphere. The concordance of the effective measuring times of the dosemeter with the real exposure times of the persons concerned safeguards representative measuring results. The main factor of uncertainty in establishing individual radiation loads on the basis of Rn measurements, the assumption of mean steady-state factors, is thus eliminated. The dosemeter stands out by its matchbox size, simple use, sufficient detection efficiency, and its good value for money. Applications of the dosemeter comprise both routine measurements of large, professionally exposed groups of persons, and measurements of individual persons in areas with increased or varying Rn/RnDP concentrations. The optimum exposure time of the dosemeter is three months. (orig.)

  18. Calibration of PADC-based neutron area dosemeters in the neutron field produced in the treatment room of a medical LINAC

    International Nuclear Information System (INIS)

    PADC-based nuclear track detectors have been widely used as convenient ambient dosemeters in many working places. However, due to the large energy dependence of their response in terms of ambient dose equivalent (H∗(10)) and to the diversity of workplace fields in terms of energy distribution, the appropriate calibration of these dosemeters is a delicate task. These are among the reasons why ISO has introduced the 12789 Series of Standards, where the simulated workplace neutron fields are introduced and their use to calibrate neutron dosemeters is recommended. This approach was applied in the present work to the UAB PADC-based nuclear track detectors. As a suitable workplace, the treatment room of a 15 MV Varian CLINAC DHX medical accelerator, located in the Ospedale S. Chiara (Pisa), was chosen. Here the neutron spectra in two points of tests (1.5 m and 2 m from the isocenter) were determined with the INFN-LNF Bonner Sphere Spectrometer equipped with Dysprosium activation foils (Dy-BSS), and the values of H∗(10) were derived on this basis. The PADC dosemeters were exposed in these points. Their workplace specific H*(10) responses were determined and compared with those previously obtained in different simulated workplace or reference (ISO 8529) neutron fields. - Highlights: ► The neutron field of a medical LINAC was used to calibrate PADC neutron dosemeters. ► The neutron spectra were derived with a Dy-foil based Bonner Sphere Spectrometer. ► Workplace specific calibration factor were derived for the PADC dosemeters. ► These factors were compared with those obtained in reference neutron fields

  19. Fiber-optic-coupled dosemeter for remote optical sensing of radiation

    International Nuclear Information System (INIS)

    Remote sensing technologies for the detection and measurement of ionizing radiation exposure are of current interest for applications such as patient dose verification during radiotherapy and the monitoring of environmental contaminants. Fiberoptic-based sensing is attractive due to the advantages of small size, low cost, long life and freedom from electromagnetic interference. Several fiberoptic-based radiation sensing systems have been described that utilize radiation induced changes in the optical characteristics of the fiber such as reduced transmission as a result of darkening of the glass, optical phase shifts due to heating, or changes in the birefringence of a polarization-maintaining fiber. The measurement of radiation induced darkening is limited in both sensitivity and dynamic range and requires long fiber lengths. Phase shift measurements require the use of single-mode lasers, phase sensitive interferometric detection, long fiber lengths and complex signal processing techniques. Alternatively, thermoluminescent (TL) phosphor powders have been coated onto fiberoptic cables and remote dosimetry measurements performed using traditional laser heating techniques. The sensitivity is limited by the requirement for a very thin layer of phosphor material, due to problems associated with light scattering and efficient heating by thermal diffusion. In this paper we report the development of an all-optical, fiber-optic-coupled, thermoluminescence dosemeter for remote radiation sensing that offers significant advantages compared to previous technologies. We recently reported the development of an optically transparent, TL glass material having exceptionally good characteristics for traditional dosimetry applications. We also reported a modified TL glass incorporating a rare earth ion dopant in order to absorb light from a semiconductor laser and utilize the absorbed light energy to internally heat the glass and release the trapped electrons. (author)

  20. Dosimetric studies of the eye lens using a new dosemeter – Surveys in interventional radiology departments

    International Nuclear Information System (INIS)

    During interventional radiology (IR) and cardiology (IC) procedures, medical staff can receive high doses to their eye lenses. The Retrospective Evaluation of Lens Injuries and Dose study organized in Argentina in 2010 found incipient opacity in 50% of IC physicians and 41% of IC technicians/nurses. These results, added to the recommendations of the International Commission on Radiological Protection, which lowered their former occupational equivalent dose limit for the lens, led us to assess the eye lens dose, Hp(3), during interventional procedures. To this end, a new dosemeter was designed and calibrated at the National Atomic Energy Commission of Argentina to evaluate Hp(3). Personal dose equivalent (Hp(10)), and Hp(3) were assessed for 3 months in two IC and IR departments. An Alderson phantom was used to simulate monthly exposures of five occupational staff members. Hp(3) and Hp(10) were obtained monthly for 14 occupational staff members exposed to 121 IR and IC procedures. We concluded that the annual effective dose and Hp(3) were lower than 0.3 and 10 mSv, respectively and the average cumulative Hp(3) for working life was lower than 400 and 200 mSv for physicians and technicians/scrub nurse, respectively. An occupational annual dose constraint of 0.3 mSv was calculated. - Highlights: • An eye lens dosimeters was designed at the Personal Dosimetry Laboratory of CNEA. • A successful dosimetric survey in two interventional departments was done. • The annual effective dose and the annual eye lens dose are lower than the ICRP dose thresholds. • In order to reduce doses actions should be promoted to maximize radiation protection

  1. Obtention of thermoluminescent efficiencies by means of irradiation of TLD-100 dosemeters with proton beams helium and carbon

    International Nuclear Information System (INIS)

    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)

  2. Determination of kinetic parameters in Tl dosemeters of LiF: Mg, Cu, P + PTFE developed in the ININ

    International Nuclear Information System (INIS)

    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 (α), beta (β) and gamma (γ). 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 being

  3. Development of quality assurance procedures for thermoluminescent CaSO4:Dy-teflon skived tape dosemeter

    International Nuclear Information System (INIS)

    CaSO4:Dy-Teflon TLD dosemeter material has been manufactured locally in a 0.4 mm thick continuous tape form. Fourteen batches have been examined for physical thickness, density, spectral transmission, diffuse optical density, beta transmission and TL output per unit area for evolving a procedure for quality assurance of the TLD element for large scale production. With the exception of two batches, the TL output per unit area of the tape for a number of batches lies within ±7% of that for a standard batch. (author)

  4. Organ and effective dose evaluation in diagnostic radiology based on in-phantom dose measurements with novel photodiode-dosemeters

    International Nuclear Information System (INIS)

    Organ and the effective doses of patients undergoing clinical X-ray examinations of chest and abdomen were evaluated with an anthropomorphic phantom and a new dosimetry system. The system was comprised of 34 pin photodiode dosemeters placed in/on particular tissues or organs of the anthropomorphic phantom, where the tissues and organs are defined by the International Commission on Radiological Protection (ICRP) to estimate the effective doses. Dosemeter signals were acquired on a personal computer directly, and converted into absorbed doses, from which the organ and the effective doses were evaluated on the computer. Our study showed that organ doses ranged from <0.01 to 0.72 mGy in routine X-ray radiography of chest and of abdomen and from 0.07 to 55.91 mGy in routine computed tomography (CT) examinations with current multi-slice CT scanners. The effective dose observed in the chest CT examination was approximately 300 times higher than that in chest radiography. (authors)

  5. 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. PMID:26170437

  6. Dosimetric studies in children and adolescents using thermoluminescence dosemeters following radiation exposure from panoramic dental X-ray units

    International Nuclear Information System (INIS)

    For the determination of the somatic radiation exposure of children and adolescents by X-ray films with the status X panorama X-ray unit personal dosimetric measurements were carried out by means of thermoluminescence dosemeters (LiF and CaSO4) in 46 patients aged 7 to 16 years. The non-screen film 'ORWO TF 13' and the screen film 'ORWO TF 2' in connection with flexible intensifying screens were used. During the exposure the dosemeters were always fixed at the same measuring points being situated within or outside the mouth of the patient. The maximum radiation exposure was registered at those points where the transparent window of the hollow anode introduced into the mouth of the patient was directly opposite to the palatal and lingual, mucosa resp. With a maxillary or mandibular panorama film and the use of non-screen films doses of 60 to 80 mGy (6 - 8 rd) were determined. Using TF 2 screen films in connection with flexible intensifying screens the values for exposure time and radiation dose could be decreased by more than 50%. Basing on these results not only a strict indication but also the use of intensifying screens have to be required for the performance of radiodiagnostical examination with status X panorama X-ray units. (author)

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

    International Nuclear Information System (INIS)

    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 deg. and deviates only at larger angles of incidence. Thus, calibrations (usually performed at 0 deg. radiation incidence) are practically equivalent on both the slab and the cylinder phantoms. However, type tests (up to 75 deg. or even 90 deg. 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. (authors)

  8. Calibration of an eye lens dosemeter in terms of Hp(3) to be used in interventional radiology

    International Nuclear Information System (INIS)

    Recently, the International Commission on Radiological Protection has reviewed epidemiological evidences suggesting that there were tissue reaction effects in the eye lens below the previously considered absorbed dose threshold. A new statement related to the eye lens was issued that changed the absorbed dose threshold and reduced the dose limits for occupationally exposed persons. As consequence, some planned exposures require eye lens dosimetry and a debate was raised on the adequacy of the dosimetric quantity and on its method of measurement. The aim of this work was to study the methodology for calibrating the EYE-DTM holder with a TLD-100H Harshaw chip detector and to determine its angular and energy dependences in terms of personal dose equivalent, Hp(3). - Highlights: • Results of calibration of the eye lens dosemeters, in terms of Hp(3). • The proposal of phantoms and specific dosemeters for eye lens have proved viable. • The tests carried out met the limits of acceptance proposed by ISO. • The good performance of the tests may suggest a reduction in the acceptance limits

  9. 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)

  10. 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...

  11. The use of albedo neutron dosemeters for the measurement of low doses in mixed photon neutron radiation fields at transport casks for high active waste

    International Nuclear Information System (INIS)

    Radiation exposure of the police forces accompanying transports of spent fuel elements and high-active waste form reprocessing (HAW) is determined by means of albedo dosemeters. The official dosimetry services use this type of dosemeter to mesure the personal dose in mixed gamma/neutron radiation fields above all for routine monitoring of workers occupationally exposed to radiation. The present report describes the detailed set-up and functioning of the albedo dosemeter, the process of obtaining the photon and neutron personal dose from the detector indications as well as the determination of the detection limit of the total personal dose of the albedo dosemeter according to the methods specified in the valid standards. Determination of the detection limit is based on the experience gained during previous transports, on measurements performed at transport casks, on results of type tests at PTB (Federal Physical and Technical Authority), on the measurement uncertainties obtained from the annual intercomparison measurements of the PTB as well as on the test irradiation specially performed in the range of small neutron and photon doses under laboratory conditions. For the dosimetry systems of the dosimetry services and the specific transport conditions, a reference level of 100 μSv was specified with regard to the dose detection limit. (orig.)

  12. The MCNP-4C2 design of a two element photon/electron dosemeter that uses magnesium/copper/phosphorus doped lithium fluoride

    International Nuclear Information System (INIS)

    The Health Protection Agency is changing from using detectors made from 7LiF:Mg,Ti in its photon/electron personal dosemeters, to 7LiF:Mg,Cu,P. Specifically, the Harshaw TLD-700H card is to be adopted. As a consequence of this change, the dosemeter holder is also being modified not only to accommodate the shape of the new card, but also to optimize the photon and electron response characteristics of the device. This redesign process was achieved using MCNP-4C2 and the kerma approximation, electron range/energy tables with additional electron transport calculations, and experimental validation, with different potential filters compared; the optimum filter studied was a polytetrafluoroethylene disc of diameter 18 mm and thickness 4.3 mm. Calculated relative response characteristics at different angles of incidence and energies between 16 and 6174 keV are presented for this new dosemeter configuration and compared with measured type-test results. A new estimate for the energy-dependent relative light conversion efficiency appropriate to the 7LiF:Mg,Cu,P was also derived for determining the correct dosemeter response. (authors)

  13. Development of a neutron dosemeter for personnel dosimetry with direct response of dose equivalent in neutron fields of different energy spectra. 2

    International Nuclear Information System (INIS)

    The evaluation of neutron dosemeters in personnel dosimetry using dielectric track detectors is described. Etched mica foils are evaluated by means of spark counting. The efficiency is presented in dependence on etching time. For single evaluation of the etch pits due to fission fragments the dose equivalent can be calculated as a multiple of the sparks number

  14. Response of electret dosemeters to eletrons with energies of 3 MeV, 7 MeV, 11 MeV

    International Nuclear Information System (INIS)

    The response of the electret dosemeter to electrons of 3,7 and 11 MeV from an accelerator Mevatron 12 is studied. Two external coatings (polyethylene or nylon) are used and a comparative evaluation is presented. (M.A.C.)

  15. Several techniques for improving energy dependence of a commercial personal neutron dosemeter package based on PADC track detector

    International Nuclear Information System (INIS)

    The practical applicability of several techniques has been investigated for improving the energy dependence of PADC-based personal neutron dosemeter for a commercial dose-assessment service. Under a constraint of no modification in detector material and the fixed chemical processes, two technical attempts have been investigated: an analysis of etch-pit data obtained by microscopic observation and a design of radiator structure. In addition to the number of etch-pits, information of their distribution in terms of various parameters was analyzed. It was found that the two-window method was possibly applicable to the distribution in the etch-pit size and the gray-level. In the latter, a performance of radiator-degrader structure has been confirmed experimentally, and it was found to be one of most promising techniques.

  16. A Modification of Gamma Surveymeter Dosemeter 3007A for Monitoring Use Ethernet by PLC T100MD Series

    International Nuclear Information System (INIS)

    It has been modified a gamma surveymeter Dosemeter 3007A. The Surveymeter represents analogous surveymeter, so that an interface for data acquisition is required. Acquisition system from surveymeter is added to the voltage amplifier module from 0 - 200 mV to 0 - 5 V. This voltage value will represent of doses 0 - 5 mR/hour. Hereinafter the analogous signal 0 - 5 V as signal of input to peripheral of PLC T100MD series. Data in the form of processed analogous signal presented at local display of PLC. For long distance monitoring, data have been sent to a computer from PLC by ethernet. After this modification, the surveymeter can be used to monitor from long distance. By using Internet Service Provider, monitoring can be done at any time and any where as long as network internet is available. (author)

  17. Application of workplace correction factors to dosemeter results for the assessment of personal doses at nuclear facilities

    International Nuclear Information System (INIS)

    Ratios of Hp(10) and H*(10) were determined with reference instruments in a number of workplace fields within the nuclear industry and used to derive workplace-specific correction factors. When commercial survey meter results together with these factors were applied to the results of the locally used personal dosemeters their results improved and became within 0.7 and 1.7 of the reference values or better depending on the response of the survey meter. A similar result was obtained when a correction was determined with a prototype reference instrument for Hp(10) after adjustment of its response. Commercially available survey instruments both for photon and neutron H*(10) measurements agreed with the reference instruments in most cases to within 0.5-1.5. Those conclusions are derived from results reported within the EC supported EVIDOS contract. (authors)

  18. Improvement and calibration of a SSNT personal dosemeter and study of importance of albedo factor for dose calculation

    International Nuclear Information System (INIS)

    The Neutriran albedo neutron dosemeter has been improved and calibrated for neutron personal dosimetry. The Monte Carlo code MCNP4b was used to calculate the thermal neutrons backscattered from the body (albedo factor). Backscattering from the wall, ceiling and floor in calibration room was considered also via simulation by MCNP4C. A semi automated counting system applying a high-resolution scanner was used for counting of tracks. An 241Am source was used to produce similar alpha particles from 10B (n,α) 7Li reaction for the optimisation of scanner parameters to distinguish and separate the tracks in SSNTD, which lead to a better distinction between etched alpha tracks and, consequently, a higher linear region of dose characteristic. (authors)

  19. Performance of the electronic personal dosemeter for neutron 'saphydose-n' at different workplaces of nuclear facilities

    International Nuclear Information System (INIS)

    This paper mainly aims at presenting the measurements and the results obtained with the electronic personal neutron dosemeter Saphydose-N at different facilities. Three campaigns were led in the frame of the European contract EVIDOS ('Evaluation of Individual Dosimetry in Mixed Neutron and Photon Radiation Fields'). The first one consisted in the measurements at the IRSN French research laboratory in reference neutron fields generated by a thermal facility (SIGMA), radionuclide ISO sources (241AmBe; 252Cf; 252Cf(D2O)/Cd) and a realistic spectrum (CANEL/T400). The second one was performed at the Kruemmel Nuclear Power Plant (Germany) close to the boiling water reactor and to a spent fuel transport cask. The third one as realised at Mol (Belgium), at the VENUS Research Reactor and at Belgonucleaire, a fuel processing factory. (authors)

  20. A fibre optic scintillator dosemeter for absorbed dose measurements of low-energy X-ray-emitting brachytherapy sources

    International Nuclear Information System (INIS)

    A newly developed dosemeter using a 0.5 mm diameter x 0.5 mm thick cylindrical plastic scintillator coupled to the end of a fibre optic cable is capable of measuring the absorbed dose rate in water around low-activity, low-energy X-ray emitters typically used in prostate brachytherapy. Recent tests of this dosemeter showed that it is possible to measure the dose rate as a function of distance in water from 2 to 30 mm of a 103Pd source of air-kerma strength 3.4 U (1 U = 1 μGy m2h-1), or 97 MBq (2.6 mCi) apparent activity, with good signal-to-noise ratio. The signal-to-noise ratio is only dependent on the integration time and background subtraction. The detector volume is enclosed in optically opaque, nearly water-equivalent materials so that there is no polar response other than that due to the shape of the scintillator volume chosen, in this case cylindrical. The absorbed dose rate very close to commercial brachytherapy sources can be mapped in an automated water phantom, providing a 3-D dose distribution with sub-millimeter spatial resolution. The sensitive volume of the detector is 0.5 mm from the end of the optically opaque waterproof housing, enabling measurements at very close distances to sources. The sensitive detector electronics allow the measurement of very low dose rates, as exist at centimeter distances from these sources. The detector is also applicable to mapping dose distributions from more complex source geometries such as eye applicators for treating macular degeneration. (authors)

  1. Measurements of non-target organ doses using MOSFET dosemeters for selected IMRT and 3D CRT radiation treatment procedures.

    Science.gov (United States)

    Wang, Brian; Xu, X George

    2008-01-01

    Many expressed concerns about the potential increase in second cancer risk from the widespread shift to intensity-modulated radiation therapy (IMRT) techniques from traditional 3-D conformal radiation treatment (3D CRT). This paper describes the study on in-phantom measurements of radiation doses in organ sites away from the primary tumour target. The measurements involved a RANDO((R)) phantom and Metal Oxide Semiconductor Field Effect Transistor dosemeters for selected 3D CRT and IMRT treatment plans. Three different treatment plans, 4-field 3D CRT, 6-field 3D CRT and 7-field IMRT for the prostate, were considered in this study. Steps to reconstruct organ doses from directly measured data were also presented. The dosemeter readings showed that the doses decrease as the distances increase for all treatment plans. At 40 cm from the prostate target, doses were <1% of the therapeutic dose. At this location, however, the IMRT plan resulted in an absorbed dose from photons, that is a factor of 3-5 higher than the 3D CRT treatment plans. This increase on absorbed dose is due to the increased exposure time for delivering the IMRT plan. The total monitor unit (MU) was 2850 for the IMRT case, while the MU was 1308 and 1260 for 6-field and 4-field 3D CRT cases, respectively. Findings from this case study involving the prostate treatments agree with those from previous studies that IMRT indeed delivers higher photon doses to locations that are away from the primary target. PMID:17627959

  2. 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)

  3. 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 Co60

    International Nuclear Information System (INIS)

    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-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 doesnt 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 and without

  4. 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)

  5. Photon energy response of luminescence dosemeters and its impact on assessment of Hp(10) and Hp(0.07) in mixed fields of varying energies of photons and beta radiation.

    Science.gov (United States)

    Pradhan, A S

    2002-01-01

    X and gamma rays continue to remain the main contributors to the dose to humans. As these photons of varying energies are encountered in various applications, the study of photon energy response of a dosemeter is an important aspect to ensure the accuracy in dose measurement. Responses of dosemeters have to be experimentally established because for luminescence dosemeters, they depend not only on the effective atomic number (ratio of mass energy absorption coefficients of dosemeter and tissue) of the detector, but also considerably on the luminescence efficiency and the material surrounding the dosemeters. Metal filters are generally used for the compensation of energy dependence below 200 keV and/or to provide photon energy discrimination. It is noted that the contribution to Hp(0.07) could be measured more accurately than Hp(10). For the dosemeters exhibiting high photon energy-dependent response, estimation of the beta component of Hp(0.07) becomes very difficult in the mixed field of beta radiation and photons of energy less than 100 keV. Recent studies have shown that the thickness and the atomic number of metal filters not only affect the response below 200 keV but also cause a significant over-response for high energy (>6 MeV) photons often encountered in the environments of pressurised heavy water reactors and accelerators. PMID:12382729

  6. Eye lens monitoring for interventional radiology personnel: dosemeters, calibration and practical aspects of H-p(3) monitoring. A 2015 review

    OpenAIRE

    Carinou, Eleftheria; Ferrari, Paolo; Ciraj Bjelac, Olivera; Ginjaume Egido, Mercè; Sans Merce, Marta; O'Connor, Una

    2015-01-01

    A thorough literature review about the current situation on the implementation of eye lens monitoring has been performed in order to provide recommendations regarding dosemeter types, calibration procedures and practical aspects of eye lens monitoring for interventional radiology personnel. Most relevant data and recommendations from about 100 papers have been analysed and classified in the following topics: challenges of today in eye lens monitoring; conversion coefficients, phantoms and cal...

  7. 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)

  8. The energy and angle dependence of response in terms of the ICRU quantities of the new design of NRPB neutron personal dosemeter

    International Nuclear Information System (INIS)

    In the present design of neutron dosemeter the detector consists of a uniquely-encoded element of polyallyl diglycol carbonate (PADC), 27 x 39 x 0.5 mm whose rear surface is in contact with a piece of nylon-6 of similar size. The PADC and nylon are heat-sealed inside a polyethylene/aluminium laminate pouch and enclosed in a simple polypropylene holder with no other filters or radiators. The rear surface only of the PADC is electrochemically etched. The fast neutron response is mainly a result of recoil protons generated in the PADC itself. There is also a contribution from reactions with oxygen and carbon nuclei. The thermal neutron response and a (lower) response up to about 1 keV is a result of protons produced by the neutron capture reactions 14N(n,p)14C in the piece of nylon. The new holder is moulded from nylonh-6. The PADC detector element is held between the two halves of the holder whose good fit prevents the ingress of foreign matter. The new design saves effort in the issuing of dosemeters although this cost saving is partly offset by the nonreusable holder. The new dosemeter has been type-tested in terms of the new (ICRU) International Commission on Radiation Units, secondary quantities and also environment effects (temperature and humidity) have been investigated for storage before and after irradiation. These latter investigations have shown no difference between the two designs of dosemeter for the effects of environment/storage. (author)

  9. Energy response of GR-200A thermoluminescence dosemeters to 60Co and to monoenergetic synchrotron radiation in the energy range 28-40 keV.

    Science.gov (United States)

    Emiro, F; Di Lillo, F; Mettivier, G; Fedon, C; Longo, R; Tromba, G; Russo, P

    2016-01-01

    The response of LiF:Mg,Cu,P thermoluminescence dosemeters (type GR-200A) to monoenergetic radiation of energy 28, 35, 38 and 40 keV was evaluated with respect to irradiation with a calibrated (60)Co gamma-ray source. High-precision measurements of the relative air kerma response performed at the SYRMEP beamline of the ELETTRA synchrotron radiation facility (Trieste, Italy) showed a significant deviation of the average response to low-energy X-rays from that to (60)Co, with an over-response from 6 % (at 28 keV) to 22 % (at 40 keV). These data are not consistent with literature data for these dosemeters, where model predictions gave deviation from unity of the relative air kerma response of about 10 %. The authors conclude for the need of additional determinations of the low-energy relative response of GR-200A dosemeters, covering a wider range of monoenergetic energies sampled at a fine energy step, as planned in future experiments by their group at the ELETTRA facility. PMID:25737582

  10. Effect of short-term sensitivity loss in LiF:Mg,Cu,P thermoluminescent dosemeter and its implications on personnel dosimetry operations

    International Nuclear Information System (INIS)

    A short-term sensitivity loss in LiF:Mg,Cu,P thermoluminescent dosemeters (TLDs) was observed and is described. Its observation occurred during a pre-irradiation anneal with a slightly elevated maximum temperature (5-15 deg. C), which causes notable under-response (5-10 %) of the subsequent read at the recommended time-temperature profile (TTP), which has a peak temperature of 260 deg. C. A subsequent irradiation and reading using the recommended TTP showed partial or complete recovery of the TLD's sensitivity. To the best of our knowledge, there were no publications on possible implications of a one-time 5-15 deg. C overheat of LiF:Mg,Cu,P TLDs during anneal. This is not unusual when several readers with some variations in their heating cycles are used to calibrate and process the same population of dosemeters. A special test to identify if a small uncontrolled overheating of a dosemeter element has occurred was developed and tested. Two practical implications of the effect of a short-term sensitivity loss in LiF:Mg,Cu,P, e.g. inconsistency in results of metrological traceability verification and reporting of false neutron doses, are described in detail. Simple indicators of a small uncontrolled overheating are provided. (authors)

  11. Integral dosemeter as an indicator of external irradiation of organisms in water discharged from nuclear power plants

    International Nuclear Information System (INIS)

    The results are discussed of experiments whose objective was to identify an indicator of external irradiation of organisms in water discharged from nuclear power plants and to measure doses in the water and in the sediments, or to assess external irradiation of organisms in conditions similar to natural conditions. The experiments proceeded in vats of 500 l each with water of a natural river composition and in tanks of 25 to 60 l in volume with water without sediments. CaSO4:Dy or Tm thermoluminescence detectors in lead filters of 0.3 mm or 0.5 mm in thickness and in a plastic cover, respectively, were found to be the most suitable dosemeters. The experimental results of dose measurement were compared to doses calculated from activities in water. The experiments also showed that for quick display of increased radionuclide contribution in water and/or for the determination of doses of external irradiation of moving water organisms it is appropriate to deploy detectors in water at a point remote from the sediment and in the sediment. (Z.M.). 3 tabs., 10 refs

  12. 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)

  13. On the use of LiF:Mg,Ti thermoluminescence dosemeters in space--a critical review.

    Science.gov (United States)

    Horowitz, Y S; Satinger, D; Fuks, E; Oster, L; Podpalov, L

    2003-01-01

    The use of LiF:Mg,Ti thermoluminescence dosemeters (TLDs) in space radiation fields is reviewed. It is demonstrated in the context of modified track structure theory and microdosimetric track structure theory that there is no unique correlation between the relative thermoluminescence (TL) efficiency of heavy charged particles, neutrons of all energies and linear energy transfer (LET). Many experimental measurements dating back more than two decades also demonstrate the multivalued, non-universal, relationship between relative TL efficiency and LET. It is further demonstrated that the relative intensities of the dosimetric peaks and especially the high-temperature structure are dependent on a large number of variables, some controllable, some not. It is concluded that TL techniques employing the concept of LET (e.g. measurement of total dose, the high-temperature ratio (HTR) methods and other combinations of the relative TL efficiency of the various peaks used to estimate average Q or simulate Q-LET relationships) should be regarded as lacking a sound theoretical basis, highly prone to error and, as well, lack of reproducibility/universality due to the absence of a standardised experimental protocol essential to reliable experimental methodology. PMID:14653322

  14. 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. PMID:23825221

  15. Chromosomal analysis and application of biological dosimetry in two cases of apparent over exposure

    International Nuclear Information System (INIS)

    The gamma radiation calibration curve of 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)

  16. Evaluation of dose equivalent and identification of energy rangeby the electronic personal dosemeter for neutron 'Saphydose-N' at different workplaces of nuclear facilities

    International Nuclear Information System (INIS)

    Full text: According to the transposition of the Directive 96/29/EURATOM into the French legislation, any worker operating in a controlled area has to be monitored by 'passive' and 'active' dosemeters. Electronic personal dosemeters are especially needed for optimization of workplaces. In nuclear facilities, some of the workers are likely to be exposed to mixed neutron-photon fields. If the dosimetry of the photons is relatively well controlled, the neutron dosimetry raises more difficulties. In this context, the Institute for Radiological Protection and Nuclear Safety (IRSN) has developed an electronic device based on a silicon detector: the 'Saphydose-N' dosemeter. It is composed of several detectors and covers more than eight energy decades. The Saphydose-N device complies with recommendations of standard IEC 1323. As the radiation fields produced in laboratory are not strictly representative to those encountered at workplaces, IRSN evaluated the response of Saphydose-N at various workplaces from nuclear industry. Several campaigns were performed in the framework of the European contract EVIDOS ('Evaluation of Individual Dosimetry in Mixed Neutron and Photon Radiation Fields'). Saphydose-N was carried out at a fuel processing plant, at the Nuclear Power Plant close to the boiling water reactor, near the transport and storage cask and at the Research Reactor. This paper mainly aims at presenting the measurements, the identification of the energy range and the results obtained with the electronic personal neutron Saphydose-N at different facilities. The results are compared with reference values, defined by other partners in EVIDOS project, for ambient and personal dose equivalent. (author)

  17. Relative thermoluminescent efficiencies proton/gamma and helium/gamma of peaks of high temperature in TLD-100 dosemeters

    International Nuclear Information System (INIS)

    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)

  18. Comparison of two models for the X-ray dispersion produced in a Novillo Tokamak with measurements make with thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    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)

  19. Comparison measurements with official neutron personal dosemeters - Implementation of changes according to the new Euratom basic standard 96/29 applicable in Germany

    International Nuclear Information System (INIS)

    The Directive concerning personal dosimetry services determines that the PTB has to perform annual comparison measurements of all types of neutron personal dosemeters used in Germany. Up to now the measurement quantity has been the directional dose equivalent H'(10). As a consequence of the acceptance of the Euratom basic standard 96/29 by the German government, in the future the personal dose equivalent Hp(10) will be used for these comparison measurements. This work describes the determination of the personal dose equivalent for calibration, presents the necessary conversion coefficients, and describes the relevant irradiation conditions. (orig.)

  20. 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)

  1. Biological Threats

    Science.gov (United States)

    ... Workplace Plans School Emergency Plans Main Content Biological Threats Biological agents are organisms or toxins that can ... for Disease Control and Prevention . Before a Biological Threat Unlike an explosion, a biological attack may or ...

  2. A model of heavy ion detection in physical and biological systems

    International Nuclear Information System (INIS)

    Track structure theory (the Katz model) and its application to the detection of heavy ions in physical and biological systems are reviewed. Following the use of a new corrected formula describing the radial distribution of average dose around the path of a heavy ion, based on results of Monte Carlo calculations and on results of experimental measurements, better agreement is achieved between model calculations and experimentally measured relative effectiveness, for enzymatic and viral systems, for the Fricke dosemeter and for alanine and thermoluminescent (TDL-700) dosemeters irradiated with beams of heavy charged particles. From experimentally measured RBE dependences for survival and frequency of neoplastic transformations in a mammalian cell culture irradiated with beams of energetic heavy ions, values of model parameters for these biological endpoints have been extracted, and a model extrapolation to the low-dose region performed. Results of model calculations are then compared with evaluations of the lung cancer hazard in populations exposed to radon and its progeny. The model can be applied to practical phenomenological analysis of radiation damage in solid-state systems and to dosimetry of charged particle and fast neutron beams using a variety of detectors. The model can also serve as a guide in building more basic models of the action of ionizing radiation with physical and biological systems and guide of development of models of radiation risk more relevant than that used presently. 185 refs., 31 figs., 3 tabs. (author)

  3. Characteristic parameters analysis on diagnostic X-ray beams for dosemeter calibration

    International Nuclear Information System (INIS)

    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

  4. Studying dosimetric parameters of thermoluminescent dosemeter of CaSO4:Dy powder made in the Nuclear Research Institute for personal radiation dosimetry

    International Nuclear Information System (INIS)

    The research group of the Nuclear Research Institute (NRI) itself studied and successfully made thermoluminescent dosemeters (TLDs) using powder material of CaSO4:Dy in 2014. For external personal dosimetry, dosimetric parameters of the TLDs were surveyed by radiating with various gamma doses of 137Cs source and measured by Rexon-320 Reader such as glow curve with temperature, calibration factor (or response value), homogeneity of the batch, reproducibility of measurement, linearity of dose response, limit of detection, fading, light sensitivity, dose-rate dependence, and energy dependence of the response, etc. The studied results were shown that the dosemeters were ensured for personal dosimetry according to the standards of IEC-61066:2006. Besides, the TLDs were also radiated with standard doses of gamma (137Cs) and X-rays at the Secondary Standards Dosimetry Laboratory (SSDL) of the Institute for Nuclear Science and Technology in Hanoi. Comparison results on dose were shown that the TLDs have been confident. Therefore, they have been used for routinely external personal dosimetry for radiation workers in the NRI and other radiation installations from the beginning of 2015. (author)

  5. Evaluation of a personal and environmental dosemeter based on CR-39 track detectors in quasi-monoenergetic neutron fields

    International Nuclear Information System (INIS)

    In this paper, the evaluation of the dosimetric capability of a detector based on a CR-39 solid-state nuclear track detector coupled to a 1 cm thickness of PMMA radiator was made with the aim of understanding the applicability of this technique to personal and environmental neutron dosimetry. The dosemeter has been exposed to monoenergetic and quasi-monoenergetic neutron beams at PTB in Braunschweig, Germany and at Ithemba Laboratories, in Faure, South Africa, with peak energies ranging from 0.565 to 100 MeV. The results showed a response that is almost independent of the neutron energy in the whole energy range. Solid-state nuclear track detectors (SSNTDs) can be successfully used to measure particle linear energy transfer (LET) by measuring the track image parameters(1, 2). For practical applications, the LET can be used to derive a good approximation of the ambient dose equivalent and the personal dose equivalent(2). The detector, meant for neutron dosimetry, is realised by coupling the CR-39 SSNTD, primarily made of polyallyl diglycol carbonate (PADC) to a PMMA [composition (C5O2H8)n] radiator. The neutron interaction in PMMA provides recoil proton via (n,p) elastic scattering. This channel of charged particle production dominates up to a neutron energy of around 7-8 MeV. For higher neutron energies, elastic and inelastic scattering cross section of oxygen and carbon becomes important. The effect on the passive detectors is that tracks are not only produced by recoil protons but by heavier charged secondary particles. The exact evaluation of the secondary particle energy distribution is out of the scope of the present paper. Using the method described in this paper, the response of the PADC detectors, coupled with plastic converters proved to be almost independent of the neutron energy, in a wide energy range (0.565-100 MeV). This is particularly interesting for personal and environmental dosimetry applications, since this neutron energy range is wide enough

  6. 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)

  7. 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)

  8. Equipment for dosemeter calibration

    International Nuclear Information System (INIS)

    The device is used for precise calibration of dosimetric instrumentation, such as used at nuclear facilities. The high precision of the calibration procedure is primarily due to the fact that one single and steady radiation source is used. The accurate alignment of the source and the absence of shielding materials in the beam axis make for high homogeneity of the beam and reproducibility of the measurement; this is also contributed to by the horizontal displacement of the optical bench, which ensures a constant temperature field and the possibility of adjusting the radiation source at a sufficient distance from the instrument to be calibrated. (Z.S.). 3 figs

  9. HSP as bio dosemeters

    International Nuclear Information System (INIS)

    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)

  10. Proposals for the type tests criteria and calibration conditions of passive eye lens dosemeters to be used in interventional cardiology and radiology workplaces

    International Nuclear Information System (INIS)

    The paper is aimed at making a proposal for the type test and calibration of eye lens passive dosemeters especially used in the interventional cardiology/radiology (IC/IR). Starting from the only existing standard dealing with eye lens dosimetry using TLDs (), parameters such as, detection threshold, energy and angle dependence of response criteria have been reviewed and it has been tried to harmonise them as much as possible with the IEC 62387 requirements, taking into account the particular use at IC/IR workplaces. Conversion coefficients from air kerma to dose equivalent at 3 mm depth for RQR and ISO radiation qualities, employed for type test and calibration purposes, have been calculated in a new phantom introduced within the ORAMED (Optimization of RAdiation protection for MEDical staff) project. This phantom is more representative of the head so that the estimation of Hlens by Hp(3) is more accurate.

  11. 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...... that crucially depends on the heating rate used and, therefore, the all-optical nature of the OSL procedure is an obvious advantage as it obviates the necessity to heat the material thereby avoiding destruction of the luminescence signal. It is demonstrated that the exceptional high OSL sensitivity 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....

  12. Experimental calibration and determination of the relative response for Lif: Mg, Ti(TLD-100) dosemeters at 60Co gamma and 60 kVp X-ray energies

    International Nuclear Information System (INIS)

    The thermoluminescence efficiency of LiF: Mg, Ti (TLD-100) dosemeters has been determined for photon beams from 60Co gamma rays and 60 kVp X-rays. It has been proven that light yield varies as a function of the photon energy. An experiment was performed using an X-ray beam whose spectrum has been determined by an X-ray fluorescence method. This enabled a direct calculation of the absorbed doses in the T1 material for the different operation conditions. These values and the experimental ones from measuring T1 intensities have been used to obtain the efficiency for energy X-ray spectrum. From the above values, the dosemeter T1 response, relative to 60Co, has been evaluated. (author)

  13. 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)

  14. 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.

  15. 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)

  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. 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

  18. 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 (90Sr / 90Y)

    International Nuclear Information System (INIS)

    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;α). Since H' (O. 07;α) 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-2); these dosemeters they were previously selected, [to see, Study of the Homogeneity of the response of Personal Dosemeters (Cards G-l, TLD-100) in Radiation of Countrysides of 60Co, J.T. Alvarez R. Technician Report GSR/IT/0001/94].The irradiations to effectued in secondary countryside of radiation beta of 90Sr/90Y. 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 90Sr/90Y 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; four positions of irradiation is used: glass 1 (window of 171 mg cm-2

  19. Characteristics of a 85Kr beta-particle source applied in Series 1 reference irradiations of TMDIS-1 direct ion storage dosemeters

    International Nuclear Information System (INIS)

    Characteristics necessary to specify an ISO 6980 Series 1 reference radiation field were determined for a commercially available 85Kr beta-particle source, using a BEAM EGS4 Monte Carlo code. The characteristics include residual maximum beta energy, Eres, and the uniformity of the dose rate over the calibration area. The Eres and the uniformity were also determined experimentally, using an extrapolation ionization chamber (EC) and a 0.2 cm3 parallel plate ionization chamber, respectively. The depth-dose curve measured with the EC gave a value 0.62 MeV for the Eres. Series 2 90Sr + 90Y and Series 1 85Kr beta-particle sources calibrated for Hp(0.07) at the secondary standard dosimetry laboratory (SSDL) of STUK were used to determine the energy and angular responses of TMDIS-1 direct ion storage dosemeters. The averaged zero angle Hp(0.07) responses to the 90Sr + 90Y and 85Kr reference radiations were 135 and 80%, respectively. The responses were normalized to 100%, Hp (0.07) response to 137Cs photon radiation. (authors)

  20. Transient conductance spectroscopy measurements of defect states in γ-irradiated n-channel silicon field effect transistors with possible γ-dosemeter applications

    International Nuclear Information System (INIS)

    A deep level transient capacitance spectroscopy (DLTS) system, modified for the measurement of transient conductance, has been used to observe gamma-ray induced defect centres in the gate junction of 2N4416 Si field effect transistors. The defect concentrations increased linearly wth gamma-dose in the range 50 kGy to 10 x 103 kGy (5-1000 Mrad) for the common Esub(c) - 0.17 eV level, and in the range 500 kGy to 10 x 103 kGy (50-1000 Mrad) for the levels Esub(c) - 0.22 eV and Esub(c) - 0.44 eV. Another common level, a hole trap at Esub(v) + 0.42 eV, was the only minority trap observed. The technique may be useful for measur-ing gamma-fluxes in situations inaccessible to standard dosemeters (e.g. flux-mapping)

  1. Study of a solid state micro-dosemeter based on a monolithic silicon telescope: Irradiations with low-energy neutrons and direct comparison with a cylindrical TEPC

    International Nuclear Information System (INIS)

    A silicon device based on the monolithic silicon telescope technology coupled to a tissue-equivalent converter was proposed and investigated for solid state microdosimetry. The detector is constituted by a DE stage about 2 μm in thickness geometrically segmented in a matrix of micrometric diodes and a residual-energy measurement stage E about 500 μm in thickness. Each thin diode has a cylindrical sensitive volume 9 μm in nominal diameter, similar to that of a cylindrical tissue-equivalent proportional counter (TEPC). The silicon device and a cylindrical TEPC were irradiated in the same experimental conditions with quasi-monoenergetic neutrons of energy between 0.64 and 2.3 MeV at the INFN-Legnaro National Laboratories (LNLINFN, Legnaro (Italy)). The aim was to study the capability of the silicon-based system of reproducing microdosimetric spectra similar to those measured by a reference micro-dosemeter. The TEPC was set in order to simulate a tissue site about 2 μm in diameter. The spectra of the energy imparted to the ΔE stage of the silicon telescope were corrected for tissue-equivalence through an optimized procedure that exploits the information from the residual energy measurement stage E. A geometrical correction based on parametric criteria for shape-equivalence was also applied. The agreement between the dose distributions of lineal energy and the corresponding mean values is satisfactory at each neutron energy considered. (authors)

  2. 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)

  3. Biology Notes.

    Science.gov (United States)

    School Science Review, 1982

    1982-01-01

    Presents procedures, exercises, demonstrations, and information on a variety of biology topics including labeling systems, biological indicators of stream pollution, growth of lichens, reproductive capacity of bulbous buttercups, a straw balance to measure transpiration, interaction of fungi, osmosis, and nitrogen fixation and crop production. (DC)

  4. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2009-06-01

    Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

  5. Quantum Biology

    CERN Document Server

    Sergi, Alessandro

    2009-01-01

    A critical assessment of the recent developments of molecular biology is presented. The thesis that they do not lead to a conceptual understanding of life and biological systems is defended. Maturana and Varela's concept of autopoiesis is briefly sketched and its logical circularity avoided by postulating the existence of underlying {\\it living processes}, entailing amplification from the microscopic to the macroscopic scale, with increasing complexity in the passage from one scale to the other. Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces, is criticized. It is suggested that the correct interpretation of quantum dispersion forces (van der Waals, hydrogen bonding, and so on) as quantum coherence effects hints at the necessity of including long-ranged forces (or mechanisms for them) in condensed matter theories of biological processes. Some quantum effects in biology are reviewed and quantum mechanics is acknowledge...

  6. 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)

  7. 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

  8. Pulsed X-rays for interventional radiology: tests on active personal dosemeters (APD) (European project FP7 ORAMED WP3); Rayons X pulses pour la radiologie interventionnelle: tests sur dosimetres personnel actifs

    Energy Technology Data Exchange (ETDEWEB)

    Denoziere, M.; Bordy, J.M.; Daures, J.; Lecerf, N

    2009-07-01

    this report presents the results of the tests performed on Active Personal dosemeters (A.P.D.) to check their responses in pulsed X-ray beam used in interventional X-ray radiology. this work is one of the goal of O.R.A.M.E.D W.P.3. (Optimization of radiation protection for medical staff)The response of seven A.P.D.s types was measured in terms of dose equivalent Hp (10) for different pulsed X-ray width and dose rate. (author)

  9. Biological Oceanography

    Science.gov (United States)

    Abbott, M. R.

    1984-01-01

    Within the framework of global biogeochemical cycles and ocean productivity, there are two areas that will be of particular interest to biological oceanography in the 1990s. The first is the mapping in space time of the biomass and productivity of phytoplankton in the world ocean. The second area is the coupling of biological and physical processes as it affects the distribution and growth rate of phytoplankton biomass. Certainly other areas will be of interest to biological oceanographers, but these two areas are amenable to observations from satellites. Temporal and spatial variability is a regular feature of marine ecosystems. The temporal and spatial variability of phytoplankton biomass and productivity which is ubiquitous at all time and space scales in the ocean must be characterized. Remote sensing from satellites addresses these problems with global observations of mesocale (2 to 20 days, 10 to 200 km) features over a long period of time.

  10. Biological preconcentrator

    Science.gov (United States)

    Manginell, Ronald P.; Bunker, Bruce C.; Huber, Dale L.

    2008-09-09

    A biological preconcentrator comprises a stimulus-responsive active film on a stimulus-producing microfabricated platform. The active film can comprise a thermally switchable polymer film that can be used to selectively absorb and desorb proteins from a protein mixture. The biological microfabricated platform can comprise a thin membrane suspended on a substrate with an integral resistive heater and/or thermoelectric cooler for thermal switching of the active polymer film disposed on the membrane. The active polymer film can comprise hydrogel-like polymers, such as poly(ethylene oxide) or poly(n-isopropylacrylamide), that are tethered to the membrane. The biological preconcentrator can be fabricated with semiconductor materials and technologies.

  11. Radiation cytogenetic in vitro studies on human donors in the development of a suitable biological dosimeter

    International Nuclear Information System (INIS)

    The final report is on the work carried out under the Agency research contract 3173/RB entitled ''Radiation cytogenetic in vitro studies on human donors in the development of a suitable biological dosimeter'', at the Clinical Hospital Centre ''Zvezdara'' in Belgrade, Yugoslavia. In co-operation and co-ordination dissemination with an international team of cytogeneticists under the IAEA CRP, the development of a suitable biological dosimetry system has been accomplished at the national institute to assist reliably in the absorbed radiation-dose assessment of accidentally-over-exposed personnel. The quantitative yield of asymmetrical chromosomal aberrations, such as dicentrics, rings and fragments consequent to exposure(s) to radiation overdose, help in such estimation of vital prognostic and radiation protection significance. This biological dosimeter system is particularly essential where the exposed person was not wearing any physical dosemeter during the accident. Prerequisite for implementation of an effective biological dosimetry is the availability of a reliable standard dose-response curve and an adherence to a protocol for lymphocytic chromosome analysis in first division phase of lymphocytes. The validation of the reported biological dosimeter is established through its successful analysis of a simulated over-exposure incident, with the associated error of less than 10%. Analytical cytogenetic methods for whole- and part-body acute exposures have been discussed. Part of the results have been reported in the publications under the CRP concerned

  12. Marine Biology

    Science.gov (United States)

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  13. Biology Notes.

    Science.gov (United States)

    School Science Review, 1983

    1983-01-01

    Describes laboratory procedures, demonstrations, and classroom activities/materials, including water relation exercise on auxin-treated artichoke tuber tissue; aerobic respiration in yeast; an improved potometer; use of mobiles in biological classification, and experiments on powdery mildews and banana polyphenol oxidase. Includes reading lists…

  14. 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). PMID:21227957

  15. Mesoscopic biology

    Indian Academy of Sciences (India)

    G V Shivashankar

    2002-02-01

    In this paper we present a qualitative outlook of mesoscopic biology where the typical length scale is of the order of nanometers and the energy scales comparable to thermal energy. Novel biomolecular machines, governed by coded information at the level of DNA and proteins, operate at these length scales in biological systems. In recent years advances in technology have led to the study of some of the design principles of these machines; in particular at the level of an individual molecule. For example, the forces that operate in molecular interactions, the stochasticity involved in these interactions and their spatio-temporal dynamics are beginning to be explored. Understanding such design principles is opening new possibilities in mesoscopic physics with potential applications.

  16. Biological programming

    OpenAIRE

    Ramsden, Jeremy J.; Bándi, Gergely

    2010-01-01

    Biology offers a tremendous set of concepts that are potentially very powerfully usable for the software engineer, but they have been barely exploited hitherto. In this position paper we propose a fresh attempt to create the building blocks of a programming technology that could be as successful as life. A key guiding principle is to develop and make use of unambiguous definitions of the essential features of life.

  17. Biological radioprotector

    International Nuclear Information System (INIS)

    According to the patent description, the biological radioprotector is deuterium depleted water, DDW, produced by vacuum distillation with an isotopic content lower than natural value. It appears as such or in a mixture with natural water and carbon dioxide. It can be used for preventing and reducing the ionizing radiation effects upon humans or animal organisms, exposed therapeutically, professionally or accidentally to radiation. The most significant advantage of using DDW as biological radioprotector results from its way of administration. Indeed no one of the radioprotectors currently used today can be orally administrated, what reduces the patients' compliance to prophylactic administrations. The biological radioprotector is an unnoxious product obtained from natural water, which can be administrated as food additive instead of drinking water. Dose modification factor is according to initial estimates around 1.9, what is a remarkable feature when one takes into account that the product is toxicity-free and side effect-free and can be administrated prophylactically as a food additive. A net radioprotective action of the deuterium depletion was evidenced experimentally in laboratory animals (rats) hydrated with DDW of 30 ppm D/(D+H) concentration as compared with normally hydrated control animals. Knowing the effects of irradiation and mechanisms of the acute radiation disease as well as the effects of administration of radiomimetic chemicals upon cellular lines of fast cell division, it appears that the effects of administrating DDW result from stimulation of the immunity system. In conclusion, the biological radioprotector DDW presents the following advantages: - it is obtained from natural products without toxicity; - it is easy to be administrated as a food additive, replacing the drinking water; - besides radioprotective effects, the product has also immunostimulative and antitumoral effects

  18. Marine biology

    International Nuclear Information System (INIS)

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index

  19. Marine biology

    Energy Technology Data Exchange (ETDEWEB)

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index.

  20. Reference beta radiations for calibrating dosemeters and dose ratemeters and for determining their response as a function of beta radiation energy. 1. ed.

    International Nuclear Information System (INIS)

    This International Standard specifies the requirements for reference beta radiations produced by radionuclide sources to be used for the calibration of protection level dosemeters and dose ratemeters, and for the determination of their response as a function of beta energy. It gives the characteristics of radionuclides which have been used to produce reference beta radiations, gives examples of suitable source constructions and describes methods for the measurement of the residual maximum beta energy and the absorbed dose rate at a depth of 7 mg·cm-2 in a semi-infinite tissue-equivalent medium. The energy range involved lies between 66 keV and 3.6 MeV and the absorbed dose rates are in the range from about 10 μGy·h-1 (1 mrad·h-1) to at least 10 Gy·h-1 (103 rad·h-1). This International Standard proposes two series of beta reference radiations from which the radiation necessary for determining the characteristics (calibration and energy response) of an instrument shall be selected. Series 1 reference radiations are produced by radionuclide sources used with beam flattening filters designed to give uniform dose rates over a large area at a specific distance. The proposed sources of 90Sr+90Y, 204TI and 147Pm produce maximum dose rates of approximately 5mGy·h-1 (0.5 rad·h-1). Series 2 reference radiations are produced without the use of beam flattening filters which allows a range of source-to-calibration plane distances to be used. Close to the sources only relatively small areas of uniform dose rate are produced but this Series has the advantage of extending the energy and dose rate ranges beyond those of Series 1. The radionuclides used are those of Series 1 with the addition of the radionuclides 14C and 106Ru+106Rh; these sources produce dose rates of up to 10 Gy·h-1 (103 rad·h-1)

  1. Radiation protection of medical staff: a coordinated action by EURADOS on extremely dosimetry and the use of active personnel dosemeters (CONRAD)

    International Nuclear Information System (INIS)

    subgroup of WG9 dealt specifically with the use of extremity dosemeters in medical radiation fields. Active personal dosimeters (APDs) are very efficient tools to monitor occupational doses in real time during exposure and provide selectable alarm levels to avoid high doses. Interventional radiology operators belong to a specific worker category, which would benefit from a real time, accurate assessment of their dose. Another subgroup dealt with the adequate dosimetry of scattered photons, using APDs. They must be able to respond to low-energy (10-100 keV) and pulsed radiation with relatively high instantaneous dose rates

  2. Biological Databases

    Directory of Open Access Journals (Sweden)

    Kaviena Baskaran

    2013-12-01

    Full Text Available Biology has entered a new era in distributing information based on database and this collection of database become primary in publishing information. This data publishing is done through Internet Gopher where information resources easy and affordable offered by powerful research tools. The more important thing now is the development of high quality and professionally operated electronic data publishing sites. To enhance the service and appropriate editorial and policies for electronic data publishing has been established and editors of article shoulder the responsibility.

  3. Radiation induced damage to the cells of pig hairs: a biological indicator of radiation dose and dose distribution in skin

    International Nuclear Information System (INIS)

    Radiation damage to the matrix cells of actively growing pig hairs resulted in a transient reduction in diameter. This was clearly dose dependent for doses in the range 0.5-5 Gy for 250 kV X rays and 3-8 Gy surface dose for 90Sr β rays. While the relationship between the percentage reduction in hair diameter and the X ray dose was linear between 0.5 and 5 Gy, the skin surface dose for β rays and the percentage reduction in hair diameter was found to be best fitted by a quadratic equation. Differences in the effect produced by X and β ray irradiation can be attributed to the absorption of β rays with depth in the dermis and a correction for this has been applied. This system would appear to have considerable potential for use as a biological dosemeter. (author)

  4. Biological biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Jorge-Herrero, E. [Servicio de Cirugia Experimental. Clinica Puerta de Hierro, Madrid (Spain)

    1997-05-01

    There are a number of situations in which substances of biological origin are employed as biomaterials. Most of them are macromolecules derived from isolated connective tissue or the connective tissue itself in membrane form, in both cases, the tissue can be used in its natural form or be chemically treated. In other cases, certain blood vessels can be chemically pretreated and used as vascular prostheses. Proteins such as albumin, collagen and fibrinogen are employed to coat vascular prostheses. Certain polysaccharides have also been tested for use in controlled drug release systems. Likewise, a number of tissues, such as dura mater, bovine pericardium, procine valves and human valves, are used in the preparation of cardiac prostheses. We also use veins from animals or humans in arterial replacement. In none of these cases are the tissues employed dissimilar to the native tissues as they have been chemically modified, becoming a new bio material with different physical and biochemical properties. In short, we find that natural products are being utilized as biomaterials and must be considered as such; thus, it is necessary to study both their chemicobiological and physicomechanical properties. In the present report, we review the current applications, problems and future prospects of some of these biological biomaterials. (Author) 84 refs.

  5. Biological effects

    International Nuclear Information System (INIS)

    Following an introduction into the field of cellular radiation effect considering the most important experimental results, the biological significance of the colony formation ability is brought out. The inactivation concept of stem cells does not only prove to be good, according to the present results, in the interpretation of the pathogenesis of acute radiation effects on moult tissue, it also enables chronicle radiation injuries to be interpreted through changes in the fibrous part of the organs. Radiation therapy of tumours can also be explained to a large extent by the radiation effect on the unlimited reproductiveness of tumour cells. The more or less similar dose effect curves for healthy and tumour tissue in practice lead to intermittent irradiation. The dependence of the intermittent doses and intervals on factors such as Elkind recovery, synchronisation, redistribution, reoxygenation, repopulation and regeneration are reviewed. (ORU/LH)

  6. Creating biological nanomaterials using synthetic biology

    International Nuclear Information System (INIS)

    Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems. (review)

  7. Creating biological nanomaterials using synthetic biology

    Directory of Open Access Journals (Sweden)

    MaryJoe K Rice

    2014-01-01

    Full Text Available Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems.

  8. Electronic dosemeter development - final stages

    International Nuclear Information System (INIS)

    An electronic personal dosimetry service has been described together with the procedure which is being adopted to gain approval in the UK for monitoring the exposure of classified workers. NRPB considers this to be the next logical development in personal dosimetry and it has been shown that the device offers a number of advantages for this purpose. (Author)

  9. Electric dosemeters. Application in radiodiagnosis

    International Nuclear Information System (INIS)

    This work relates the realization of an useful dosimeter in radiodiagnosis. The detection is founded on depolarization measurement of an electret submitted to X rays. First of all we have studied several methods for the making of electrets with a polymer tip of low thickness (100 μm). Is described an assembly for the making and carrying out of the samples measurement. Are also presented the results obtained by two polarization methods. The relative importance of the two mechanisms which stem out from these results are discussed in the last part. The shape of the curves is justified

  10. Barcode scanner for ring dosemeters

    International Nuclear Information System (INIS)

    A barcode scanner for circular bar codes was developed as an additional module for a dosimeter-reader manufactured in the USA. The new scanner had to fulfill all existing interface specifications (power supply, serial interface) to be integrated seamlessly into the existing instrument. The size of the barcode reader had to be compact enough to fit into the instrument without the need for additional external components. The barcode scanner has been realized using image processing technology. The system is designed in a way to fulfill all the functions of the 'old' laser barcode scanner (decoding of linear codes) plus the additional function of decoding circular barcodes in parallel. The system consists of CCD (charge coupled device) camera, infrared illumination, image processing hardware (frame grabber) and computer. The computer runs an image processing software developed in C. The result of the development effort is a fully functional prototype that is to be adapted for serial production (with minor modifications) by the US-manufacturer. (author)

  11. Dosemeter for ultraviolet-radiation

    International Nuclear Information System (INIS)

    A commercial available, wrist watch like instrument for the measurement of UV-exposure by sun radiation will be described (SUNWATCH). The conditions will be indicated, under which this device can be used for the determination of the UV-exposure at workplace. (orig.)

  12. Structural Biology Fact Sheet

    Science.gov (United States)

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area What is structural biology? Structural biology is a field of science focused ...

  13. Thin layer a-Al{sub 2}O{sub 3}:C beta dosemeters for the assessment of current dose rate in teeth due to {sup 90}Sr intake and comparison with electron paramagnetic resonance dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Goksu, H.Y.; Semiochkina, N.; Shiskina, E.A.; Wieser, A.; El-Faramawy, N.A.; Degteva, M.O.; Jacob, P.; Ivanov, D.V

    2002-07-01

    The use of thin-layer a-Al{sub 2}O{sub 3}:C thermoluminescence detectors (TLDs) for the assessment of current beta dose rate in human teeth due to {sup 90}Sr intake is investigated. The teeth used in this study were collected from members of the Techa river population who were exposed to radiation as a result of releases of the Mayak plutonium production facilities (Southern Urals-Russia) between 1949 and 1956. The beta dose rates from different parts of the tooth (enamel, crown dentine, and root) were determined by storing the detectors over the samples in a shielded environment. The cumulative dose measured by electron paramagnetic resonance (EPR) in different dental tissues is found to be proportional to the current dose rate obtained from a-Al{sub 2}O{sub 3}:C thermoluminescence dosemeters. The retention of {sup 90}Sr in various parts of the teeth is discussed. (author)

  14. Thin layer a-Al2O3:C beta dosemeters for the assessment of current dose rate in teeth due to 90Sr intake and comparison with electron paramagnetic resonance dosimetry

    International Nuclear Information System (INIS)

    The use of thin-layer a-Al2O3:C thermoluminescence detectors (TLDs) for the assessment of current beta dose rate in human teeth due to 90Sr intake is investigated. The teeth used in this study were collected from members of the Techa river population who were exposed to radiation as a result of releases of the Mayak plutonium production facilities (Southern Urals-Russia) between 1949 and 1956. The beta dose rates from different parts of the tooth (enamel, crown dentine, and root) were determined by storing the detectors over the samples in a shielded environment. The cumulative dose measured by electron paramagnetic resonance (EPR) in different dental tissues is found to be proportional to the current dose rate obtained from a-Al2O3:C thermoluminescence dosemeters. The retention of 90Sr in various parts of the teeth is discussed. (author)

  15. Simulating Biological and Non-Biological Motion

    Science.gov (United States)

    Bruzzo, Angela; Gesierich, Benno; Wohlschlager, Andreas

    2008-01-01

    It is widely accepted that the brain processes biological and non-biological movements in distinct neural circuits. Biological motion, in contrast to non-biological motion, refers to active movements of living beings. Aim of our experiment was to investigate the mechanisms underlying mental simulation of these two movement types. Subjects had to…

  16. A Brief Introduction to Chinese Biological Biological

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Chinese Biological Abstracts sponsored by the Library, the Shanghai Institutes for Biological Sciences, the Biological Documentation and Information Network, all of the Chinese Academy of Sciences, commenced publication in 1987 and was initiated to provide access to the Chinese information in the field of biology.

  17. Creating biological nanomaterials using synthetic biology

    OpenAIRE

    MaryJoe K Rice; Ruder, Warren C.

    2014-01-01

    Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic bi...

  18. Biological effects of radiation

    International Nuclear Information System (INIS)

    This fourth chapter presents: cell structure and metabolism; radiation interaction with biological tissues; steps of the production of biological effect of radiation; radiosensitivity of tissues; classification of biological effects; reversibility, transmissivity and influence factors; pre-natal biological effects; biological effects in therapy and syndrome of acute irradiation

  19. Use of FISH-translocations analyses for retrospective biological dosimetry: How stable are stable chromosome aberrations?

    International Nuclear Information System (INIS)

    Chromosome aberrations, in particular dicentrics, in peripheral blood lymphocytes are used to estimate the absorbed dose immediately following a radiation accident. However, difficulties for dose estimation arise with old exposures, due to a decline of cells containing unstable dicentric aberrations. The fluorescence in situ hybridisation (FISH) technique employing chromosome specific DNA libraries to 'paint' individual human chromosomes has opened new perspectives for rapid and reliable detection of stable chromosome aberrations such as translocations. The inherent stability of translocations over cell generations has enabled them to be used as a biodosemeter. However, due to the limited life of circulating T-lymphocytes, a level of uncertainty exists on the long-term persistence of stable translocations. The objectives of the present work are to present the current state of knowledge on the stability of translocations detected by FISH. The following aspects have been considered; (1) experience so far of retrospective biological dosimetry in humans following accidental and occupational over-exposure, (2) animal studies using mice and monkeys, (3) the influence of subsequent cell divisions on the yield and persistence of translocations following in vitro irradiation of human lymphocytes, and (4) the needs for further work to standardise and validate the use of FISH as a biological dosemeter, and to investigate the influence of various parameters such as radiation quality, dose rate and the discrimination of sub-types of translocations on persistence. (author)

  20. Biological and sanitary effects of non ionizing radiations

    International Nuclear Information System (INIS)

    The objective of this day was to encourage the collaborations, especially multidisciplinary, on the biological, clinical, epidemiological and dosimetry aspects. The different presentations are as follow: the magneto reception among animals; the health and radio frequencies foundation; expo-metry to radio frequency fields: dosemeters evaluation; the electro-optical probes as tool of hyper frequency dosimetry; characterisation of emissions produced by the low consumption fluo-compact lamps in the perspective of persons exposure; strong and weak points of epidemiology; numerical dosimetry in low frequency magnetic and/or electric field; exposure of the French population to the 50 Hz magnetic field: first results for the Ile-de-france and Rhone alpes areas; characterisation of the exposure to the very low frequency magnetic fields in the town of Champlan; measurement of the residential exposure of children to the extremely low frequency, very low frequency and radiofrequency (E.L.F., V.L.F. and R.F.) fields and modeling of the high voltage magnetic field face to the child leukemia; effects of radiofrequency signals of wireless communications on the young animals; study of combined effects of 2.45 GHz microwaves and a known mutagen on DNA by two different approaches; effects on the oxidizing stress of nervous cells exposure to an (enhanced data rates for GSM evolution) E.D.G.E. signal; is environmental epidemiology still a science; cardiac implants and exposure to 50 Hz electromagnetic fields in occupational environment; the tanning by artificial UV radiation: norms and legislation; mobiles phones, Wi Fi and other wireless communications; effects on health of 50-60 Hz electromagnetic fields; natural and artificial ultraviolet radiations: a proved risk. (N.C.)

  1. Biological conversion system

    Science.gov (United States)

    Scott, C.D.

    A system for bioconversion of organic material comprises a primary bioreactor column wherein a biological active agent (zymomonas mobilis) converts the organic material (sugar) to a product (alcohol), a rejuvenator column wherein the biological activity of said biological active agent is enhanced, and means for circulating said biological active agent between said primary bioreactor column and said rejuvenator column.

  2. Synthetic biology: insights into biological computation.

    Science.gov (United States)

    Manzoni, Romilde; Urrios, Arturo; Velazquez-Garcia, Silvia; de Nadal, Eulàlia; Posas, Francesc

    2016-04-18

    Organisms have evolved a broad array of complex signaling mechanisms that allow them to survive in a wide range of environmental conditions. They are able to sense external inputs and produce an output response by computing the information. Synthetic biology attempts to rationally engineer biological systems in order to perform desired functions. Our increasing understanding of biological systems guides this rational design, while the huge background in electronics for building circuits defines the methodology. In this context, biocomputation is the branch of synthetic biology aimed at implementing artificial computational devices using engineered biological motifs as building blocks. Biocomputational devices are defined as biological systems that are able to integrate inputs and return outputs following pre-determined rules. Over the last decade the number of available synthetic engineered devices has increased exponentially; simple and complex circuits have been built in bacteria, yeast and mammalian cells. These devices can manage and store information, take decisions based on past and present inputs, and even convert a transient signal into a sustained response. The field is experiencing a fast growth and every day it is easier to implement more complex biological functions. This is mainly due to advances in in vitro DNA synthesis, new genome editing tools, novel molecular cloning techniques, continuously growing part libraries as well as other technological advances. This allows that digital computation can now be engineered and implemented in biological systems. Simple logic gates can be implemented and connected to perform novel desired functions or to better understand and redesign biological processes. Synthetic biological digital circuits could lead to new therapeutic approaches, as well as new and efficient ways to produce complex molecules such as antibiotics, bioplastics or biofuels. Biological computation not only provides possible biomedical and

  3. Computational Systems Chemical Biology

    OpenAIRE

    Oprea, Tudor I.; May, Elebeoba E.; Leitão, Andrei; Tropsha, Alexander

    2011-01-01

    There is a critical need for improving the level of chemistry awareness in systems biology. The data and information related to modulation of genes and proteins by small molecules continue to accumulate at the same time as simulation tools in systems biology and whole body physiologically-based pharmacokinetics (PBPK) continue to evolve. We called this emerging area at the interface between chemical biology and systems biology systems chemical biology, SCB (Oprea et al., 2007).

  4. Pictures of Synthetic Biology

    OpenAIRE

    Cserer, Amelie; Seiringer, Alexandra

    2009-01-01

    This article is concerned with the representation of Synthetic Biology in the media and by biotechnology experts. An analysis was made of German-language media articles published between 2004 and 2008, and interviews with biotechnology-experts at the Synthetic Biology conference SB 3.0 in Zurich 2007. The results have been reflected in terms of the definition of Synthetic Biology, applications of Synthetic Biology and the perspectives of opportunities and risks. In the media, Synthetic Biolog...

  5. The use of enriched 6Li and 7Li LiF: Mg, Cu, P glass-rod thermoluminescent dosemeters for linear accelerator out-of-field radiation dose measurements

    International Nuclear Information System (INIS)

    6Li:Mg, Cu, P and 7Li:Mg, Cu, P glass-rod thermoluminescent dosemeters (TLDs) were used for measurements of out-of-field photon and neutron doses produced by Varian iX linear accelerator. Both TLDs were calibrated using 18-MV X-ray beam to investigate their dose-response sensitivity and linearity. CR-39 etch-track detectors (Luxel+, Landauer) were employed to provide neutron dose data to calibrate 6Li:Mg, Cu, P TLDs at various distances from the iso-centre. With cadmium filters employed, slow neutrons (< 0.5 eV) were distinguished from fast neutrons. The average in-air photon dose equivalents per monitor unit (MU) ranged from 1.5±0.4 to 215.5±94.6 uμSv at 100 and 15 cm from the iso-centre, respectively. Based on the cross-calibration factors obtained with CR-39 etch-track detectors, the average in-air fast neutron dose equivalents per MU range from 10.6±3.8 to 59.1±49.9 uμSv at 100 and 15 cm from the iso-centre, respectively. Contribution of thermal neutrons to total neutron dose equivalent was small: 3.1±7.2 uμSv per MU at 15 cm from the iso-centre. (authors)

  6. The use of enriched 6Li and 7Li Lif:Mg,Cu,P glass-rod thermoluminescent dosemeters for linear accelerator out-of-field radiation dose measurements.

    Science.gov (United States)

    Takam, R; Bezak, E; Liu, G; Marcu, L

    2012-06-01

    (6)LiF:Mg,Cu,P and (7)LiF:Mg,Cu,P glass-rod thermoluminescent dosemeters (TLDs) were used for measurements of out-of-field photon and neutron doses produced by Varian iX linear accelerator. Both TLDs were calibrated using 18-MV X-ray beam to investigate their dose-response sensitivity and linearity. CR-39 etch-track detectors (Luxel+, Landauer) were employed to provide neutron dose data to calibrate (6)LiF:Mg,Cu,P TLDs at various distances from the isocentre. With cadmium filters employed, slow neutrons (calibration factors obtained with CR-39 etch-track detectors, the average in-air fast neutron dose equivalents per MU range from 10.6±3.8 to 59.1±49.9 μSv at 100 and 15 cm from the isocentre, respectively. Contribution of thermal neutrons to total neutron dose equivalent was small: 3.1±7.2 μSv per MU at 15 cm from the isocentre. PMID:21873634

  7. Long-term investigation on self-irradiation and sensitivity to cosmic rays of TL detector types TLD-200, TLD-700, MCP-N and new phosphate glass dosemeters

    International Nuclear Information System (INIS)

    The cosmic component of background gamma radiation, the intrinsic background (or 'self-dose') and fading of TLD-600, TLD-700 and TLD-200 (all produced by Harshaw), MCP-N (LiF:Mg,Cu,P produced by INP Kradow) and phosphate glass dosemeters SC-1 (Toshiba Glass) were measured over a period of 557 days at the Asse salt-mine 775 m below ground level, in a steel shielding at the FZK (Karlsruhe Research Centre) laboratory and in a buoy off-shore of an artificial lake. Assuming a reference cosmic dose rate of 37 nGy.h-1 over the lake, the relative response to cosmic rays was estimated at 0.76 for the LiF:Mg, Ti and CaF2:Dy detectors and 0.86 and 0.81 for the phosphate glass and LiF:Mg,Cu,P detectors, respectively. Fading of detectors of all types did not exceed 5% per annum, including long-term storage at 33oC in the slat mine. (author)

  8. 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)

  9. Advances in Biological Science.

    Science.gov (United States)

    Oppenheimer, Steven B.; And Others

    1988-01-01

    Reviews major developments in areas that are at the cutting edge of biological research. Areas include: human anti-cancer gene, recombinant DNA techniques for the detection of Huntington disease carriers, and marine biology. (CW)

  10. Biology of Blood

    Science.gov (United States)

    ... Mail Facebook TwitterTitle Google+ LinkedIn Home Blood Disorders Biology of Blood Overview of Blood Medical Dictionary Also ... Version. DOCTORS: Click here for the Professional Version Biology of Blood Overview of Blood Components of Blood ...

  11. Engineering scalable biological systems

    OpenAIRE

    Lu, Timothy K.

    2010-01-01

    Synthetic biology is focused on engineering biological organisms to study natural systems and to provide new solutions for pressing medical, industrial, and environmental problems. At the core of engineered organisms are synthetic biological circuits that execute the tasks of sensing inputs, processing logic, and performing output functions. In the last decade, significant progress has been made in developing basic designs for a wide range of biological circuits in bacteria, yeast, and mammal...

  12. Systems interface biology

    OpenAIRE

    Francis J Doyle; Stelling, Jörg

    2006-01-01

    The field of systems biology has attracted the attention of biologists, engineers, mathematicians, physicists, chemists and others in an endeavour to create systems-level understanding of complex biological networks. In particular, systems engineering methods are finding unique opportunities in characterizing the rich behaviour exhibited by biological systems. In the same manner, these new classes of biological problems are motivating novel developments in theoretical systems approaches. Henc...

  13. Biological Races in Humans

    OpenAIRE

    Templeton, Alan R.

    2013-01-01

    Races may exist in humans in a cultural sense, but biological concepts of race are needed to access their reality in a non-species-specific manner and to see if cultural categories correspond to biological categories within humans. Modern biological concepts of race can be implemented objectively with molecular genetic data through hypothesis-testing. Genetic data sets are used to see if biological races exist in humans and in our closest evolutionary relative, the chimpanzee. Using the two m...

  14. Upgrading Undergraduate Biology Education

    Science.gov (United States)

    Musante, Susan

    2011-01-01

    On many campuses throughout the country, undergraduate biology education is in serious need of an upgrade. During the past few decades, the body of biological knowledge has grown exponentially, and as a research endeavor, the practice of biology has evolved. Education research has also made great strides, revealing many new insights into how…

  15. Biology Myth-Killers

    Science.gov (United States)

    Lampert, Evan

    2014-01-01

    "Biology Myth-Killers" is an activity designed to identify and correct common misconceptions for high school and college introductory biology courses. Students identify common myths, which double as biology misconceptions, and use appropriate sources to share the "truth" about the myths. This learner-centered activity is a fun…

  16. Designing synthetic biology.

    Science.gov (United States)

    Agapakis, Christina M

    2014-03-21

    Synthetic biology is frequently defined as the application of engineering design principles to biology. Such principles are intended to streamline the practice of biological engineering, to shorten the time required to design, build, and test synthetic gene networks. This streamlining of iterative design cycles can facilitate the future construction of biological systems for a range of applications in the production of fuels, foods, materials, and medicines. The promise of these potential applications as well as the emphasis on design has prompted critical reflection on synthetic biology from design theorists and practicing designers from many fields, who can bring valuable perspectives to the discipline. While interdisciplinary connections between biologists and engineers have built synthetic biology via the science and the technology of biology, interdisciplinary collaboration with artists, designers, and social theorists can provide insight on the connections between technology and society. Such collaborations can open up new avenues and new principles for research and design, as well as shed new light on the challenging context-dependence-both biological and social-that face living technologies at many scales. This review is inspired by the session titled "Design and Synthetic Biology: Connecting People and Technology" at Synthetic Biology 6.0 and covers a range of literature on design practice in synthetic biology and beyond. Critical engagement with how design is used to shape the discipline opens up new possibilities for how we might design the future of synthetic biology. PMID:24156739

  17. Biological Water or Rather Water in Biology?

    Czech Academy of Sciences Publication Activity Database

    Jungwirth, Pavel

    2015-01-01

    Roč. 6, č. 13 (2015), s. 2449-2451. ISSN 1948-7185 Institutional support: RVO:61388963 Keywords : biological water * protein * interface Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 7.458, year: 2014

  18. A new analysis of radiation-induced cytogenetic damage in human lymphocytes using the PCC technique, and its implications for biological dosimetry and the understanding of cell-cycle-dependent radiosensitivity fluctuations

    International Nuclear Information System (INIS)

    The objectives of the project are: to develop a sensitive biological dosemeter, based on the analysis of C-banded peripheral blood lymphocyte prematurely condensed chromosomes (PCCs), for the early assessment of radiation injury and the establishment of absorbed dose estimates in accidental overexposures; and to elucidate the mechanisms of radiation action at the molecular, chromosomal and cellular levels by the study of the effects of DNA repair inhibitors on the repair of radiation damage, effects of BrdUrd incorporation on radiation damage, effects of hyperthermia on the induction and repair of radiation-induced damage, and induction and repair of radiation damage in an X-ray sensitive CHO mutant cell line. (authors) 16 refs., 1 fig

  19. Synthetic biological networks

    International Nuclear Information System (INIS)

    Despite their obvious relationship and overlap, the field of physics is blessed with many insightful laws, while such laws are sadly absent in biology. Here we aim to discuss how the rise of a more recent field known as synthetic biology may allow us to more directly test hypotheses regarding the possible design principles of natural biological networks and systems. In particular, this review focuses on synthetic gene regulatory networks engineered to perform specific functions or exhibit particular dynamic behaviors. Advances in synthetic biology may set the stage to uncover the relationship of potential biological principles to those developed in physics. (review article)

  20. Quantum biological information theory

    CERN Document Server

    Djordjevic, Ivan B

    2016-01-01

    This book is a self-contained, tutorial-based introduction to quantum information theory and quantum biology. It serves as a single-source reference to the topic for researchers in bioengineering, communications engineering, electrical engineering, applied mathematics, biology, computer science, and physics. The book provides all the essential principles of the quantum biological information theory required to describe the quantum information transfer from DNA to proteins, the sources of genetic noise and genetic errors as well as their effects. Integrates quantum information and quantum biology concepts; Assumes only knowledge of basic concepts of vector algebra at undergraduate level; Provides a thorough introduction to basic concepts of quantum information processing, quantum information theory, and quantum biology; Includes in-depth discussion of the quantum biological channel modelling, quantum biological channel capacity calculation, quantum models of aging, quantum models of evolution, quantum models o...

  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. 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)

  3. Branching processes in biology

    CERN Document Server

    Kimmel, Marek

    2015-01-01

    This book provides a theoretical background of branching processes and discusses their biological applications. Branching processes are a well-developed and powerful set of tools in the field of applied probability. The range of applications considered includes molecular biology, cellular biology, human evolution and medicine. The branching processes discussed include Galton-Watson, Markov, Bellman-Harris, Multitype, and General Processes. As an aid to understanding specific examples, two introductory chapters, and two glossaries are included that provide background material in mathematics and in biology. The book will be of interest to scientists who work in quantitative modeling of biological systems, particularly probabilists, mathematical biologists, biostatisticians, cell biologists, molecular biologists, and bioinformaticians. The authors are a mathematician and cell biologist who have collaborated for more than a decade in the field of branching processes in biology for this new edition. This second ex...

  4. Spectroscopy of biological nanocrystals

    OpenAIRE

    Ortac, Inanc; Severcan, Feride

    2007-01-01

    Nanocrystals have gained much interest in recent years, due to their unusual properties allowing interesting applications in physical and biological science. In this literature review, biological nanocrystals are discussed from the spectroscopic point of view. Firstly, the theory behind the outstanding abilities of the nanocrystals is described. Secondly, the spectroscopic properties of biological nanocrystals are mentioned. Lastly, the use of nanocrystals with various spectroscopic applicati...

  5. Biological detector and method

    Energy Technology Data Exchange (ETDEWEB)

    Sillerud, Laurel; Alam, Todd M; McDowell, Andrew F

    2014-04-15

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  6. Biological detector and method

    Energy Technology Data Exchange (ETDEWEB)

    Sillerud, Laurel; Alam, Todd M.; McDowell, Andrew F.

    2015-11-24

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  7. Introducing Aquatic Biology

    OpenAIRE

    Kinne, Otto; Browman, Howard I.; Seaman, Matthias

    2007-01-01

    The Inter-Research Science Center (IR) journals Marine Ecology Progress Series (MEPS) and Aquatic Microbial Ecology (AME) have been receiving increasing numbers of high-quality manuscripts that are principally biological, rather than ecological. With regret, we have had to turn these submissions away. Also, leading limnologists have for many years suggested that IR should provide an outlet for top quality articles on freshwater biology and ecology. Aquatic Biology (...

  8. Biological detector and method

    Science.gov (United States)

    Sillerud, Laurel; Alam, Todd M; McDowell, Andrew F

    2013-02-26

    A biological detector includes a conduit for receiving a fluid containing one or more magnetic nanoparticle-labeled, biological objects to be detected and one or more permanent magnets or electromagnet for establishing a low magnetic field in which the conduit is disposed. A microcoil is disposed proximate the conduit for energization at a frequency that permits detection by NMR spectroscopy of whether the one or more magnetically-labeled biological objects is/are present in the fluid.

  9. Glycobiology Current Molecular Biology

    OpenAIRE

    Sabire KARAÇALI

    2003-01-01

    Carbohydrate chemistry evolved into carbohydrate biochemistry and gradually into the biology of carbohydrates, or glycobiology, at the end of the last century. Glycobiology is the new research area of modern molecular biology, and it investigates the structure, biosynthesis and biological functions of glycans. The numbers, linkage types (a or b), positions, binding points and functional group differences of monosaccharides create microheterogeneity. Thus, numerous glycoforms with precise stru...

  10. Foundations of biology

    OpenAIRE

    Sikorav, Jean-Louis; Braslau, Alan; Goldar, Arach

    2014-01-01

    It is often stated that there are no laws in biology, where everything is contingent and could have been otherwise, being solely the result of historical accidents. Furthermore, the customary introduction of fundamental biological entities such as individual organisms, cells, genes, catalysts and motors remains largely descriptive; constructive approaches involving deductive reasoning appear, in comparison, almost absent. As a consequence, both the logical content and principles of biology ne...

  11. Biological aerosol background characterization

    Science.gov (United States)

    Blatny, Janet; Fountain, Augustus W., III

    2011-05-01

    To provide useful information during military operations, or as part of other security situations, a biological aerosol detector has to respond within seconds or minutes to an attack by virulent biological agents, and with low false alarms. Within this time frame, measuring virulence of a known microorganism is extremely difficult, especially if the microorganism is of unknown antigenic or nucleic acid properties. Measuring "live" characteristics of an organism directly is not generally an option, yet only viable organisms are potentially infectious. Fluorescence based instruments have been designed to optically determine if aerosol particles have viability characteristics. Still, such commercially available biological aerosol detection equipment needs to be improved for their use in military and civil applications. Air has an endogenous population of microorganisms that may interfere with alarm software technologies. To design robust algorithms, a comprehensive knowledge of the airborne biological background content is essential. For this reason, there is a need to study ambient live bacterial populations in as many locations as possible. Doing so will permit collection of data to define diverse biological characteristics that in turn can be used to fine tune alarm algorithms. To avoid false alarms, improving software technologies for biological detectors is a crucial feature requiring considerations of various parameters that can be applied to suppress alarm triggers. This NATO Task Group will aim for developing reference methods for monitoring biological aerosol characteristics to improve alarm algorithms for biological detection. Additionally, they will focus on developing reference standard methodology for monitoring biological aerosol characteristics to reduce false alarm rates.

  12. 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

  13. Biological Clocks & Circadian Rhythms

    Science.gov (United States)

    Robertson, Laura; Jones, M. Gail

    2009-01-01

    The study of biological clocks and circadian rhythms is an excellent way to address the inquiry strand in the National Science Education Standards (NSES) (NRC 1996). Students can study these everyday phenomena by designing experiments, gathering and analyzing data, and generating new experiments. As students explore biological clocks and circadian…

  14. Experimenting with Mathematical Biology

    Science.gov (United States)

    Sanft, Rebecca; Walter, Anne

    2016-01-01

    St. Olaf College recently added a Mathematical Biology concentration to its curriculum. The core course, Mathematics of Biology, was redesigned to include a wet laboratory. The lab classes required students to collect data and implement the essential modeling techniques of formulation, implementation, validation, and analysis. The four labs…

  15. Bioinformatics and School Biology

    Science.gov (United States)

    Dalpech, Roger

    2006-01-01

    The rapidly changing field of bioinformatics is fuelling the need for suitably trained personnel with skills in relevant biological "sub-disciplines" such as proteomics, transcriptomics and metabolomics, etc. But because of the complexity--and sheer weight of data--associated with these new areas of biology, many school teachers feel…

  16. Biological Macromolecule Crystallization Database

    Science.gov (United States)

    SRD 21 Biological Macromolecule Crystallization Database (Web, free access)   The Biological Macromolecule Crystallization Database and NASA Archive for Protein Crystal Growth Data (BMCD) contains the conditions reported for the crystallization of proteins and nucleic acids used in X-ray structure determinations and archives the results of microgravity macromolecule crystallization studies.

  17. Biological pretreatment sewages water

    OpenAIRE

    Veselý, Václav

    2009-01-01

    Bachelor's thesis deals with waste water purification at the stage of pre-inflow of water into the biological waste water treatment plants. It is divided into two parts, a theoretical and calculation. The theoretical part deals about sewage water and the method of biological treatment. Design proposal is part of the activation tank for quantity EO.

  18. Integrated Biological Control

    International Nuclear Information System (INIS)

    Biological control is any activity taken to prevent, limit, clean up, or remediate potential environmental, health and safety, or workplace quality impacts from plants, animals, or microorganisms. At Hanford the principal emphasis of biological control is to prevent the transport of radioactive contamination by biological vectors (plants, animals, or microorganisms), and where necessary, control and clean up resulting contamination. Other aspects of biological control at Hanford include industrial weed control (e.g.; tumbleweeds), noxious weed control (invasive, non-native plant species), and pest control (undesirable animals such as rodents and stinging insects; and microorganisms such as molds that adversely affect the quality of the workplace environment). Biological control activities may be either preventive (apriori) or in response to existing contamination spread (aposteriori). Surveillance activities, including ground, vegetation, flying insect, and other surveys, and apriori control actions, such as herbicide spraying and placing biological barriers, are important in preventing radioactive contamination spread. If surveillance discovers that biological vectors have spread radioactive contamination, aposteriori control measures, such as fixing contamination, followed by cleanup and removal of the contamination to an approved disposal location are typical response functions. In some cases remediation following the contamination cleanup and removal is necessary. Biological control activities for industrial weeds, noxious weeds and pests have similar modes of prevention and response

  19. Biological sample collector

    Science.gov (United States)

    Murphy, Gloria A.

    2010-09-07

    A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

  20. Optics of Biological Particles

    CERN Document Server

    Hoekstra, Alfons; Videen, Gorden

    2007-01-01

    This book covers the optics of single biological particles, both theory and experiment, with emphasis on Elastic Light Scattering and Fluorescence. It deals with the optics of bacteria (bio-aerosols), marine particles (selected phytoplankton communities) and red and white blood cells. Moreover, there are dedicated chapters on a general theory for scattering by a cell, and modelling and simulation of scattering by inhomogeneous biological cells. Finally, one chapter is dedicated to astro-biological signatures, discussing the possibilities for detecting non-terrestrial biological material. The volume has up-to-date discussions on new experimental and numerical techniques, and many examples of applications of these techniques in real-life systems, as used to detect and characterize e.g. biological warfare agents or human blood cells.

  1. Frontiers in mathematical biology

    CERN Document Server

    1994-01-01

    Volume 100, which is the final volume of the LNBM series serves to commemorate the acievements in two decades of this influential collection of books in mathematical biology. The contributions, by the leading mathematical biologists, survey the state of the art in the subject, and offer speculative, philosophical and critical analyses of the key issues confronting the field. The papers address fundamental issues in cell and molecular biology, organismal biology, evolutionary biology, population ecology, community and ecosystem ecology, and applied biology, plus the explicit and implicit mathematical challenges. Cross-cuttting issues involve the problem of variation among units in nonlinear systems, and the related problems of the interactions among phenomena across scales of space, time and organizational complexity.

  2. Biological and Chemical Security

    Energy Technology Data Exchange (ETDEWEB)

    Fitch, P J

    2002-12-19

    The LLNL Chemical & Biological National Security Program (CBNP) provides science, technology and integrated systems for chemical and biological security. Our approach is to develop and field advanced strategies that dramatically improve the nation's capabilities to prevent, prepare for, detect, and respond to terrorist use of chemical or biological weapons. Recent events show the importance of civilian defense against terrorism. The 1995 nerve gas attack in Tokyo's subway served to catalyze and focus the early LLNL program on civilian counter terrorism. In the same year, LLNL began CBNP using Laboratory-Directed R&D investments and a focus on biodetection. The Nunn-Lugar-Domenici Defense Against Weapons of Mass Destruction Act, passed in 1996, initiated a number of U.S. nonproliferation and counter-terrorism programs including the DOE (now NNSA) Chemical and Biological Nonproliferation Program (also known as CBNP). In 2002, the Department of Homeland Security was formed. The NNSA CBNP and many of the LLNL CBNP activities are being transferred as the new Department becomes operational. LLNL has a long history in national security including nonproliferation of weapons of mass destruction. In biology, LLNL had a key role in starting and implementing the Human Genome Project and, more recently, the Microbial Genome Program. LLNL has over 1,000 scientists and engineers with relevant expertise in biology, chemistry, decontamination, instrumentation, microtechnologies, atmospheric modeling, and field experimentation. Over 150 LLNL scientists and engineers work full time on chemical and biological national security projects.

  3. Correlation on LET-measurements using TLDs with biological effects in a proton beam of 62 MeV

    International Nuclear Information System (INIS)

    A method based on TLDs was developed which enables the measurement of the absorbed dose as well as the determination of the average LET of mixed radiation fields. This method was successfully applied in space and in aircrafts and was used to measure the absorbed dose and the LET in proton beams. Stacks of dosemeters were exposed to a modulated as well as to an unmodulated proton beam (Bragg peak) of 62 MeV protons at the Paul Scherrer Institute, Switzerland. The irradiation in the unmodulated proton beam was used to calibrated the dosemeters. The increase of HTR with increasing LET was determined. This calibration was used to measure the LET in dependence of the depth of the modulated proton beam. The modulated proton beam is usually used in proton therapy modulated over the depth of the tumor. The advantage of this technique is a constant dose over the region of modulation. Nevertheless prior measurements of the RBE have shown an increase with increasing absorber thickness. This increase of RBE was verified with the HTR-method. An increase of the HTR respectively of the LET was measured in dependence of the proton range. Furthermore a comparison of the HTR with the survival propability of V79 irradiated in the modulated beam show a good agreement. The LET measured with TLDs increases from 1.78 keV/μm to 4.83 keV/μm tissue for 30 mGy absorbed dose, the survival propability decreases from 66.5% (1.4 mm depth) to 42.8% (28.6 mm) for 2 Gy absorbed dose. In addition to these measurements biological investigations with lymphocytes were performed irradiating TLDs and lymphocytes in a polyethylene phantom at two depths (5 mm and 20 mm absorber). For each position a dose characteristic was obtained from 0.25 to 2.0 Gy. The genotoxic essay was micronuclei. The analysis of the HTR-method show an increase of HTR of 30% from position 1 to position 2, considering that the absolute values depend on the absorbed dose. (author)

  4. Neutron in biology

    Energy Technology Data Exchange (ETDEWEB)

    Niimura, Nobuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-11-01

    Neutron in biology can provide an experimental method of directly locating relationship of proteins and DNA. However, there are relatively few experimental study of such objects since it takes a lot of time to collect a sufficient number of Bragg reflections and inelastic spectra due to the low flux of neutron illuminating the sample. Since a next generation neutron source of JAERI will be 5MW spallation neutron source and its effective neutron flux will be 10{sup 2} to 10{sup 3} times higher than the one of JRR-3M, neutron in biology will open a completely new world for structural biology. (author)

  5. A Molecular Biology Database Digest

    OpenAIRE

    Bry, François; Kröger, Peer

    2000-01-01

    Computational Biology or Bioinformatics has been defined as the application of mathematical and Computer Science methods to solving problems in Molecular Biology that require large scale data, computation, and analysis [18]. As expected, Molecular Biology databases play an essential role in Computational Biology research and development. This paper introduces into current Molecular Biology databases, stressing data modeling, data acquisition, data retrieval, and the integration...

  6. SOIL BIOLOGY AND ECOLOGY

    Science.gov (United States)

    The term "Soil Biology", the study of organism groups living in soil, (plants, lichens, algae, moss, bacteria, fungi, protozoa, nematodes, and arthropods), predates "Soil Ecology", the study of interactions between soil organisms as mediated by the soil physical environment. oil ...

  7. Insecticides and Biological Control

    Science.gov (United States)

    Furness, G. O.

    1972-01-01

    Use of insecticides has been questioned due to their harmful effects on edible items. Biological control of insects along with other effective practices for checking spread of parasites on crops are discussed. (PS)

  8. Teaching evolutionary biology

    Directory of Open Access Journals (Sweden)

    Tidon Rosana

    2004-01-01

    Full Text Available Evolutionary Biology integrates several disciplines of Biology in a complex and interactive manner, where a deep understanding of the subject demands knowledge in diverse areas. Since this knowledge is often inaccessible to the majority of specialized professionals, including the teachers, we present some reflections in order to stimulate discussions aimed at the improvement of the conditions of education in this area. We examine the profile of evolutionary teaching in Brazil, based on questionnaires distributed to teachers in Secondary Education in the Federal District, on data provided by the "National Institute for Educational Studies and Research", and on information collected from teachers working in various regions of this country. Issues related to biological misconceptions, curriculum and didactic material are discussed, and some proposals are presented with the objective of aiding discussions aimed at the improvement of the teaching of evolutionary biology.

  9. Vibrations, Quanta and Biology

    CERN Document Server

    Huelga, S F

    2013-01-01

    Quantum biology is an emerging field of research that concerns itself with the experimental and theoretical exploration of non-trivial quantum phenomena in biological systems. In this tutorial overview we aim to bring out fundamental assumptions and questions in the field, identify basic design principles and develop a key underlying theme -- the dynamics of quantum dynamical networks in the presence of an environment and the fruitful interplay that the two may enter. At the hand of three biological phenomena whose understanding is held to require quantum mechanical processes, namely excitation and charge transfer in photosynthetic complexes, magneto-reception in birds and the olfactory sense, we demonstrate that this underlying theme encompasses them all, thus suggesting its wider relevance as an archetypical framework for quantum biology.

  10. Nutritional Systems Biology

    DEFF Research Database (Denmark)

    Jensen, Kasper

    and network biology has the potential to increase our understanding of how small molecules affect metabolic pathways and homeostasis, how this perturbation changes at the disease state, and to what extent individual genotypes contribute to this. A fruitful strategy in approaching and exploring the field...... biology research. The paper also shows as a proof-of-concept that a systems biology approach to diet is meaningful and demonstrates some basic principles on how to work with diet systematic. The second chapter of this thesis we developed the resource NutriChem v1.0. A foodchemical database linking...... sites of diet on the disease pathway. We propose a framework for interrogating the critical targets in colon cancer process and identifying plant-based dietary interventions as important modifiers using a systems chemical biology approach. The fifth chapter of the thesis is on discovering of novel anti...

  11. Mechanical Biological Treatment

    DEFF Research Database (Denmark)

    Bilitewski, B-; Oros, Christiane; Christensen, Thomas Højlund

    The basic processes and technologies of composting and anaerobic digestion, as described in the previous chapters, are usually used for specific or source-separated organic waste flows. However, in the 1990s mechanical biological waste treatment technologies (MBT) were developed for unsorted or...... residual waste (after some recyclables removed at the source). The concept was originally to reduce the amount of waste going to landfill, but MBT technologies are today also seen as plants recovering fuel as well as material fractions. As the name suggests the technology combines mechanical treatment...... technologies (screens, sieves, magnets, etc.) with biological technologies (composting, anaerobic digestion). Two main technologies are available: Mechanical biological pretreatment (MBP), which first removes an RDF fraction and then biologically treats the remaining waste before most of it is landfilled, and...

  12. Enhanced Biological Sampling Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is a database of a variety of biological, reproductive, and energetic data collected from fish on the continental shelf in the northwest Atlantic Ocean....

  13. Hammond Bay Biological Station

    Data.gov (United States)

    Federal Laboratory Consortium — Hammond Bay Biological Station (HBBS), located near Millersburg, Michigan, is a field station of the USGS Great Lakes Science Center (GLSC). HBBS was established by...

  14. Mammalian cell biology

    International Nuclear Information System (INIS)

    This section contains summaries of research on mechanisms of lethality and radioinduced changes in mammalian cell properties, new cell systems for the study of the biology of mutation and neoplastic transformation, and comparative properties of ionizing radiations

  15. Mechanical Biological Treatment

    DEFF Research Database (Denmark)

    Bilitewski, B-; Oros, Christiane; Christensen, Thomas Højlund

    2011-01-01

    The basic processes and technologies of composting and anaerobic digestion, as described in the previous chapters, are usually used for specific or source-separated organic waste flows. However, in the 1990s mechanical biological waste treatment technologies (MBT) were developed for unsorted or...... residual waste (after some recyclables removed at the source). The concept was originally to reduce the amount of waste going to landfill, but MBT technologies are today also seen as plants recovering fuel as well as material fractions. As the name suggests the technology combines mechanical treatment...... technologies (screens, sieves, magnets, etc.) with biological technologies (composting, anaerobic digestion). Two main technologies are available: Mechanical biological pretreatment (MBP), which first removes an RDF fraction and then biologically treats the remaining waste before most of it is landfilled, and...

  16. Laboratory of Biological Modeling

    Data.gov (United States)

    Federal Laboratory Consortium — The Laboratory of Biological Modeling is defined by both its methodologies and its areas of application. We use mathematical modeling in many forms and apply it to...

  17. The Biology of Behaviour.

    Science.gov (United States)

    Broom, D. M.

    1981-01-01

    Discusses topics to aid in understanding animal behavior, including the value of the biological approach to psychology, functional systems, optimality and fitness, universality of environmental effects on behavior, and evolution of social behavior. (DS)

  18. Biological satellite Kosmos-936

    Science.gov (United States)

    Vedeshin, L. A.

    1978-01-01

    A description is given of physiological experiments performed on the biological satellite Kosmos-936. Other experiments to determine the electrostatic and dielectric responses to the effects of cosmic radiation are discussed.

  19. Ontologies for molecular biology.

    Science.gov (United States)

    Schulze-Kremer, S

    1998-01-01

    Molecular biology has a communication problem. There are many databases using their own labels and categories for storing data objects and some using identical labels and categories but with a different meaning. A prominent example is the concept "gene" which is used with different semantics by major international genomic databases. Ontologies are one means to provide a semantic repository to systematically order relevant concepts in molecular biology and to bridge the different notions in various databases by explicitly specifying the meaning of and relation between the fundamental concepts in an application domain. Here, the upper level and a database branch of a prospective ontology for molecular biology (OMB) is presented and compared to other ontologies with respect to suitability for molecular biology (http:/(/)igd.rz-berlin.mpg.de/approximately www/oe/mbo.html). PMID:9697223

  20. Fishery Biology Database (AGDBS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Basic biological data are the foundation on which all assessments of fisheries resources are built. These include parameters such as the size and age composition of...

  1. Large Pelagics Biological Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Large Pelagics Biological Survey (LPBS) collects additional length and weight information and body parts such as otoliths, caudal vertebrae, dorsal spines, and...

  2. The Biology of Aging.

    Science.gov (United States)

    Sprott, Richard L.; And Others

    1992-01-01

    Thirteen articles in this special issue discuss aging theories, biomarkers of aging, aging research, disease, cancer biology, Alzheimer's disease, stress, oxidation of proteins, gene therapy, service delivery, biogerontology, and ethics and aging research. (SK)

  3. Synthetic biology: A foundation for multi-scale molecular biology

    OpenAIRE

    Bower, Adam G; McClintock, Maria K; Stephen S. Fong

    2010-01-01

    The field of synthetic biology has made rapid progress in a number of areas including method development, novel applications and community building. In seeking to make biology “engineerable,” synthetic biology is increasing the accessibility of biological research to researchers of all experience levels and backgrounds. One of the underlying strengths of synthetic biology is that it may establish the framework for a rigorous bottom-up approach to studying biology starting at the DNA level. Bu...

  4. Computational Thinking in Biology

    OpenAIRE

    Priami, Corrado

    2007-01-01

    The paper presents a new approach based on process calculi to systems modeling suitable for biological systems. The main characteristic of process calculi is a linguistic description level to dene incrementally and compositionally executable models. The formalism is suitable to be exploited on the same systems at dierent levels of abstractions connected through well dened formal rules. The abstraction principle that represents biological entities as interacting computational units is the basi...

  5. Biological Sciences Building

    OpenAIRE

    Kumaraswamy, Mohan

    2002-01-01

    One element of the CIVCAL project Web-based resources containing images, tables, texts and associated data on the construction of the Biological Sciences Building. The HKU Kadoorie Biological Sciences Building is an 11-storey reinforced concrete framed building with a structural steel arch roof. The building dimensions are approximately 60 metres x 30 metres. The estimated project cost for the superstructure construction (excluding the bored pile foundations) was about HK$ 400 million....

  6. Biological treatment for sewage

    OpenAIRE

    Xintai, Wang; Luc Sanya, Eric

    2007-01-01

    The sewage treatment is by no means insignificant in our world, and for many sewage treatment plants, the biological treatment is the best choice to eliminate the nutrients and organic compounds in the waste water. Today, in most waste water treatment plants, there are two main kinds of biological waste water treatment – the active sludge method and the biofilm method. Each of these two methods have their own advantages and disadvantages. For different towns or cities, the waste water treatme...

  7. Synthetic biology and biosecurity.

    Science.gov (United States)

    Robienski, Jürgen; Simon, Jürgen

    2014-01-01

    This article discusses the conflict fields and legal questions of synthetic biology, esp. concerning biosecurity. A respective jurisprudential discussion has not taken place yet in Germany apart from few statements and recommendations. But in Germany, Europe and the USA, it is generally accepted that a broad discussion is necessary. This is esp. true for the question of biosecurity and the possible dangers arising from Synthetic Biology. PMID:25845204

  8. Biological sequence analysis

    OpenAIRE

    Speed, T. P.

    2003-01-01

    This talk will review a little over a decade's research on applying certain stochastic models to biological sequence analysis. The models themselves have a longer history, going back over 30 years, although many novel variants have arisen since that time. The function of the models in biological sequence analysis is to summarize the information concerning what is known as a motif or a domain in bioinformatics, and to provide a tool for discovering instances of that motif or domain in a separa...

  9. Noise in Biology

    OpenAIRE

    Tsimring, Lev S

    2014-01-01

    Noise permeates biology on all levels, from the most basic molecular, sub-cellular processes to the dynamics of tissues, organs, organisms, and populations. The functional roles of noise in biological processes can vary greatly. Along with standard, entropy-increasing effects of producing random mutations, diversifying phenotypes in isogenic populations, limiting information capacity of signaling relays, it occasionally plays more surprising constructive roles by accelerating the pace of evol...

  10. Biological Effects of Ionizing Radiation

    Science.gov (United States)

    Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.

    1952-04-07

    This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.

  11. [Biologics and mycobacterial diseases].

    Science.gov (United States)

    Tsuyuguchi, Kazunari; Matsumoto, Tomoshige

    2013-03-01

    Various biologics such as TNF-alpha inhibitor or IL-6 inhibitor are now widely used for treatment of rheumatoid arthritis. Many reports suggested that one of the major issues is high risk of developing tuberculosis (TB) associated with using these agents, which is especially important in Japan where tuberculosis still remains endemic. Another concern is the risk of development of nontuberculous mycobacterial (NTM) diseases and we have only scanty information about it. The purpose of this symposium is to elucidate the role of biologics in the development of mycobacterial diseases and to establish the strategy to control them. First, Dr. Tohma showed the epidemiologic data of TB risks associated with using biologics calculated from the clinical database on National Database of Rheumatic Diseases by iR-net in Japan. He estimated TB risks in rheumatoid arthritis (RA) patients to be about four times higher compared with general populations and to become even higher by using biologics. He also pointed out a low rate of implementation of QuantiFERON test (QFT) as screening test for TB infection. Next, Dr. Tokuda discussed the issue of NTM disease associated with using biologics. He suggested the airway disease in RA patients might play some role in the development of NTM disease, which may conversely lead to overdiagnosis of NTM disease in RA patients. He suggested that NTM disease should not be uniformly considered a contraindication to treatment with biologics, considering from the results of recent multicenter study showing relatively favorable outcome of NTM patients receiving biologics. Patients with latent tuberculosis infection (LTBI) should receive LTBI treatment before starting biologics. Dr. Kato, a chairperson of the Prevention Committee of the Japanese Society for Tuberculosis, proposed a new LTBI guideline including active implementation of LTBI treatment, introducing interferon gamma release assay, and appropriate selection of persons at high risk for

  12. Stochastic Methods in Biology

    CERN Document Server

    Kallianpur, Gopinath; Hida, Takeyuki

    1987-01-01

    The use of probabilistic methods in the biological sciences has been so well established by now that mathematical biology is regarded by many as a distinct dis­ cipline with its own repertoire of techniques. The purpose of the Workshop on sto­ chastic methods in biology held at Nagoya University during the week of July 8-12, 1985, was to enable biologists and probabilists from Japan and the U. S. to discuss the latest developments in their respective fields and to exchange ideas on the ap­ plicability of the more recent developments in stochastic process theory to problems in biology. Eighteen papers were presented at the Workshop and have been grouped under the following headings: I. Population genetics (five papers) II. Measure valued diffusion processes related to population genetics (three papers) III. Neurophysiology (two papers) IV. Fluctuation in living cells (two papers) V. Mathematical methods related to other problems in biology, epidemiology, population dynamics, etc. (six papers) An important f...

  13. Biological races in humans.

    Science.gov (United States)

    Templeton, Alan R

    2013-09-01

    Races may exist in humans in a cultural sense, but biological concepts of race are needed to access their reality in a non-species-specific manner and to see if cultural categories correspond to biological categories within humans. Modern biological concepts of race can be implemented objectively with molecular genetic data through hypothesis-testing. Genetic data sets are used to see if biological races exist in humans and in our closest evolutionary relative, the chimpanzee. Using the two most commonly used biological concepts of race, chimpanzees are indeed subdivided into races but humans are not. Adaptive traits, such as skin color, have frequently been used to define races in humans, but such adaptive traits reflect the underlying environmental factor to which they are adaptive and not overall genetic differentiation, and different adaptive traits define discordant groups. There are no objective criteria for choosing one adaptive trait over another to define race. As a consequence, adaptive traits do not define races in humans. Much of the recent scientific literature on human evolution portrays human populations as separate branches on an evolutionary tree. A tree-like structure among humans has been falsified whenever tested, so this practice is scientifically indefensible. It is also socially irresponsible as these pictorial representations of human evolution have more impact on the general public than nuanced phrases in the text of a scientific paper. Humans have much genetic diversity, but the vast majority of this diversity reflects individual uniqueness and not race. PMID:23684745

  14. Informing Biological Design by Integration of Systems and Synthetic Biology

    OpenAIRE

    Smolke, Christina D.; Silver, Pamela A.

    2011-01-01

    Synthetic biology aims to make the engineering of biology faster and more predictable. In contrast, systems biology focuses on the interaction of myriad components and how these give rise to the dynamic and complex behavior of biological systems. Here, we examine the synergies between these two fields.

  15. Noise in biology

    International Nuclear Information System (INIS)

    Noise permeates biology on all levels, from the most basic molecular, sub-cellular processes to the dynamics of tissues, organs, organisms and populations. The functional roles of noise in biological processes can vary greatly. Along with standard, entropy-increasing effects of producing random mutations, diversifying phenotypes in isogenic populations, limiting information capacity of signaling relays, it occasionally plays more surprising constructive roles by accelerating the pace of evolution, providing selective advantage in dynamic environments, enhancing intracellular transport of biomolecules and increasing information capacity of signaling pathways. This short review covers the recent progress in understanding mechanisms and effects of fluctuations in biological systems of different scales and the basic approaches to their mathematical modeling. (review article)

  16. Traceability of biologicals

    DEFF Research Database (Denmark)

    Vermeer, Niels S; Spierings, Irina; Mantel-Teeuwisse, Aukje K;

    2015-01-01

    INTRODUCTION: Traceability is important in the postmarketing surveillance of biologicals, since changes in the manufacturing process may give rise to product- or batch-specific risks. With the expected expansion of the biosimilar market, there have been concerns about the ability to trace...... individual products within pharmacovigilance databases. AREAS COVERED: The authors discuss the present challenges in the traceability of biologicals in relation to pharmacovigilance, by exploring the processes involved in ensuring traceability. They explore both the existing systems that are in place...... for the recording of exposure information in clinical practice, as well as the critical steps involved in the transfer of exposure data to various pharmacovigilance databases. EXPERT OPINION: The existing systems ensure the traceability of biologicals down to the manufacturer within pharmacy records, but do...

  17. Epigenetics: Biology's Quantum Mechanics.

    Science.gov (United States)

    Jorgensen, Richard A

    2011-01-01

    The perspective presented here is that modern genetics is at a similar stage of development as were early formulations of quantum mechanics theory in the 1920s and that in 2010 we are at the dawn of a new revolution in genetics that promises to enrich and deepen our understanding of the gene and the genome. The interrelationships and interdependence of two views of the gene - the molecular biological view and the epigenetic view - are explored, and it is argued that the classical molecular biological view is incomplete without incorporation of the epigenetic perspective and that in a sense the molecular biological view has been evolving to include the epigenetic view. Intriguingly, this evolution of the molecular view toward the broader and more inclusive epigenetic view of the gene has an intriguing, if not precise, parallel in the evolution of concepts of atomic physics from Newtonian mechanics to quantum mechanics that are interesting to consider. PMID:22639577

  18. Epigenetics: Biology's Quantum Mechanics

    Directory of Open Access Journals (Sweden)

    Richard A Jorgensen

    2011-04-01

    Full Text Available The perspective presented here is that modern genetics is at a similar stage of development as were early formulations of quantum mechanics theory in the 1920's and that in 2010 we are at the dawn of a new revolution in genetics that promises to enrich and deepen our understanding of the gene and the genome. The interrelationships and interdependence of two views of the gene - the molecular biological view and the epigenetic view - are explored, and it is argued that the classical molecular biological view is incomplete without incorporation of the epigenetic perspective and that in a sense the molecular biological view has been evolving to include the epigenetic view. Intriguingly, this evolution of the molecular view toward the broader and more inclusive epigenetic view of the gene has an intriguing, if not precise, parallel in the evolution of concepts of atomic physics from Newtonian mechanics to quantum mechanics that are interesting to consider.

  19. Biological therapy of psoriasis

    Directory of Open Access Journals (Sweden)

    Sivamani Raja

    2010-01-01

    Full Text Available The treatment of psoriasis has undergone a revolution with the advent of biologic therapies, including infliximab, etanercept, adalimumab, efalizumab, and alefacept. These medications are designed to target specific components of the immune system and are a major technological advancement over traditional immunosuppressive medications. These usually being well tolerated are being found useful in a growing number of immune-mediated diseases, psoriasis being just one example. The newest biologic, ustekinumab, is directed against the p40 subunit of the IL-12 and IL-23 cytokines. It has provided a new avenue of therapy for an array of T-cell-mediated diseases. Biologics are generally safe; however, there has been concern over the risk of lymphoma with use of these agents. All anti-TNF-α agents have been associated with a variety of serious and "routine" opportunistic infections.

  20. 7th Annual Systems Biology Symposium: Systems Biology and Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Galitski, Timothy P.

    2008-04-01

    Systems biology recognizes the complex multi-scale organization of biological systems, from molecules to ecosystems. The International Symposium on Systems Biology has been hosted by the Institute for Systems Biology in Seattle, Washington, since 2002. The annual two-day event gathers the most influential researchers transforming biology into an integrative discipline investingating complex systems. Engineering and application of new technology is a central element of systems biology. Genome-scale, or very small-scale, biological questions drive the enigneering of new technologies, which enable new modes of experimentation and computational analysis, leading to new biological insights and questions. Concepts and analytical methods in engineering are now finding direct applications in biology. Therefore, the 2008 Symposium, funded in partnership with the Department of Energy, featured global leaders in "Systems Biology and Engineering."

  1. Biological and Pharmaceutical Nanomaterials

    Science.gov (United States)

    Kumar, Challa S. S. R.

    2006-01-01

    This first comprehensive yet concise overview of all important classes of biological and pharmaceutical nanomaterials presents in one volume the different kinds of natural biological compounds that form nanomaterials or that may be used to purposefully create them. This unique single source of information brings together the many articles published in specialized journals, which often remain unseen by members of other, related disciplines. Covering pharmaceutical, nucleic acid, peptide and DNA-Chitosan nanoparticles, the book focuses on those innovative materials and technologies needed for the continued growth of medicine, healthcare, pharmaceuticals and human wellness. For chemists, biochemists, cell biologists, materials scientists, biologists, and those working in the pharmaceutical and chemical industries.

  2. Neutron structural biology

    International Nuclear Information System (INIS)

    Neutron structural biology will be one of the most important fields in the life sciences which will interest human beings in the 21st century because neutrons can provide not only the position of hydrogen atoms in biological macromolecules but also the dynamic molecular motion of hydrogen atoms and water molecules. However, there are only a few examples experimentally determined at present because of the lack of neutron source intensity. Next generation neutron source scheduled in JAERI (Performance of which is 100 times better than that of JRR-3M) opens the life science of the 21st century. (author)

  3. The Biological Universe

    Science.gov (United States)

    Dick, Steven J.

    2000-03-01

    Introduction; 1. From the physical world to the biological universe: Democritus to Lowell; 2. Plurality of worlds and the decline of anthropocentrism; 3. The solar system: the limits of observation; 4. Solar systems beyond: the limits of theory; 5. Extraterrestrials in literature and the arts: the role of imagination; 6. The UFO controversy: on perception and deception; 7. The origin and evolution of life in the extraterrestrial context; 8. SETI: the Search for Extraterrestrial Intelligence; 9. The convergence of disciplines: birth of a new science; 10. The meaning of life; Summary and conclusion: the biological universe and the limits of science.

  4. Networks in Cell Biology = Modelling cell biology with networks

    OpenAIRE

    Buchanan, Mark; Caldarelli, Guido; De Los Rios, Paolo; Rao, Francesco; Vendruscolo, M.

    2010-01-01

    The science of complex biological networks is transforming research in areas ranging from evolutionary biology to medicine. This is the first book on the subject, providing a comprehensive introduction to complex network science and its biological applications. With contributions from key leaders in both network theory and modern cell biology, this book discusses the network science that is increasingly foundational for systems biology and the quantitative understanding of living systems. It ...

  5. European intercomparison of diagnostic dosemeters: results

    International Nuclear Information System (INIS)

    The measurement protocol for the 1990 CEC sponsored intercomparison is described and the results have been analysed. The majority of participants achieved good results, within 10% deviation of the correct value. Differences in performance can be linked to how each national centre organised the intercomparison and to national arrangements for similar measurements, particularly legislative requirements. Furthermore, certain types of instruments tended to perform well, particularly those with a flat energy response for the X ray qualities used. Participants who used instruments dedicated to mammographic and diagnostic X ray qualities, tended to obtain the best results. The greatest scope for improvement in the accuracy of measurements is in mammography, and this is related to the use of dedicated mammographic chambers. (14 figs)

  6. 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)

  7. Models in Biology.

    Science.gov (United States)

    Flannery, Maura C.

    1997-01-01

    Addresses the most popular models currently being chosen for biological research and the reasons behind those choices. Among the current favorites are zebra fish, fruit flies, mice, monkeys, and yeast. Concludes with a brief examination of the ethical issues involved, and why some animals may need to be replaced in research with model systems.…

  8. Evolution, Entropy, & Biological Information

    Science.gov (United States)

    Peterson, Jacob

    2014-01-01

    A logical question to be expected from students: "How could life develop, that is, change, evolve from simple, primitive organisms into the complex forms existing today, while at the same time there is a generally observed decline and disorganization--the second law of thermodynamics?" The explanations in biology textbooks relied upon by…

  9. Water pollution biology

    Energy Technology Data Exchange (ETDEWEB)

    Mason, C.F. [University of Essex, Colchester (United Kingdom). Dept. of Biology

    1996-12-31

    Chapter 4 of this book describes the effects of major types of pollutants on aquatic life. These are: organic pollution, eutrophication, acidification, toxic chemicals, oil, and radioactivity. The review includes an description of some of the methods of assessing the biological impacts of pollution. 50 refs., 8 figs., 3 tabs.

  10. Next-generation biology

    DEFF Research Database (Denmark)

    Rodrigues da Fonseca, Rute Andreia; Albrechtsen, Anders; Themudo, Gonçalo Espregueira;

    2016-01-01

    we present an overview of the current sequencing technologies and the methods used in typical high-throughput data analysis pipelines. Subsequently, we contextualize high-throughput DNA sequencing technologies within their applications in non-model organism biology. We include tips regarding managing...

  11. Biology task group

    International Nuclear Information System (INIS)

    The accomplishments of the task group studies over the past year are reviewed. The purposes of biological investigations, in the context of subseabed disposal, are: an evaluation of the dose to man; an estimation of effects on the ecosystem; and an estimation of the influence of organisms on and as barriers to radionuclide migration. To accomplish these ends, the task group adopted the following research goals: (1) acquire more data on biological accumulation of specific radionuclides, such as those of Tc, Np, Ra, and Sr; (2) acquire more data on transfer coefficients from sediment to organism; (3) Calculate mass transfer rates, construct simple models using them, and estimate collective dose commitment; (4) Identify specific pathways or transfer routes, determine the rates of transfer, and make dose limit calculations with simple models; (5) Calculate dose rates to and estimate irradiation effects on the biota as a result of waste emplacement, by reference to background irradiation calculations. (6) Examine the effect of the biota on altering sediment/water radionuclide exchange; (7) Consider the biological data required to address different accident scenarios; (8) Continue to provide the basic biological information for all of the above, and ensure that the system analysis model is based on the most realistic and up-to-date concepts of marine biologists; and (9) Ensure by way of free exchange of information that the data used in any model are the best currently available

  12. Situeret interesse i biologi

    DEFF Research Database (Denmark)

    Dohn, Niels Bonderup

    2006-01-01

    Interesse hævdes at spille en vigtig rolle i læring. Med udgangspunkt i interesseteori og situeret læring har jeg foretaget et studium i en gymnasieklasse med biologi på højt niveau, med henblik på at identificere hvilke forhold der har betydning for hvad der fanger elevers interesse. Jeg har...

  13. Molecular Biology of Medulloblastoma

    OpenAIRE

    J Gordon Millichap

    2007-01-01

    Current methods of diagnosis and treatment of medulloblastoma, and the influence of new biological advances in the development of more effective and less toxic therapies are reviewed by researchers at Children’s National Medical Center, The George Washington University, Washington, DC.

  14. Multiscale Biological Materials

    DEFF Research Database (Denmark)

    Frølich, Simon

    2016-01-01

    cortical bone, and the nanoscale response of bone in compression. Lastly, a framework for the investigation of biological design principles has been developed. The framework combines parametric modeling, multi-material 3D-printing, and direct mechanical testing to efficiently screen large parameter spaces...

  15. Spin glasses and biology

    CERN Document Server

    Stein, David

    1992-01-01

    This volume is an introduction to the application of techniques developed for the study of disordered systems to problems which arise in biology. Topics presented include neural networks, adaptation and evolution, maturation of the immune response, and protein dynamics and folding. This book will appeal to students and researchers interested in statistical and condensed matter physics, glasses and spin glasses, and biophysics.

  16. Biological Congress in Sweden

    Science.gov (United States)

    Bennett, D. P.

    1975-01-01

    Reports on the International Congress on the Improvement of Biology Education which was attended by delegates from fifty-eight different countries. The objectives of the Congress were to identify and analyze trends, to prepare a four-year plan for further improvement, and to prepare materials for publication by UNESCO. (GS)

  17. Antiprotons get biological

    CERN Multimedia

    2003-01-01

    After its final run in September, the first results of the Antiproton Cell Experiment (ACE) look very promising. It was the first experiment to take data on the biological effects of antiproton beams to evaluate the potential of antiprotons in radiation therapy.

  18. Plant Systems Biology (editorial)

    Science.gov (United States)

    In June 2003, Plant Physiology published an Arabidopsis special issue devoted to plant systems biology. The intention of Natasha Raikhel and Gloria Coruzzi, the two editors of this first-of-its-kind issue, was ‘‘to help nucleate this new effort within the plant community’’ as they considered that ‘‘...

  19. Nuclear physics and biology

    International Nuclear Information System (INIS)

    This paper is about nuclear instrumentation and biological concepts, based on images from appropriate Β detectors. First, three detectors are described: the SOFI detector, for gene mapping, the SOFAS detector, for DNA sequencing and the RIHR detector, for in situ hybridization. Then, the paper presents quantitative imaging in molecular genetic and functional imaging. (TEC)

  20. Biological activity determination

    Czech Academy of Sciences Publication Activity Database

    Madronová, L.; Novák, J.; Kubíček, J.; Antošová, B.; Kozler, J.; Novák, František

    New York: Nova Science Publisher, 2011 - (Madronová, L.), s. 85-103. (Chemistry Research and Applications). ISBN 978-1-61668-965-0 Institutional research plan: CEZ:AV0Z60660521 Keywords : biological activity * determination * potassium humate samples Subject RIV: CB - Analytical Chemistry, Separation