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Sample records for personnel dosimeter apd

  1. Personnel ionizing radiation dosimeter

    International Nuclear Information System (INIS)

    Williams, R.A.

    1975-01-01

    A dosimeter and method for use by personnel working in an area of mixed ionizing radiation fields for measuring and/or determining the effective energy of x- and gamma radiation; beta, x-, and gamma radiation dose equivalent to the surface of the body; beta, x-, and gamma radiation dose equivalent at a depth in the body; the presence of slow neutron, fast neutron dose equivalent; and orientation of the person wearing the dosimeter to the source of radiation is disclosed. Optionally integrated into this device and method are improved means for determining neutron energy spectrum and absorbed dose from fission gamma and neutron radiation resulting from accidental criticality

  2. Hanford personnel dosimeter supporting studies FY-1981

    International Nuclear Information System (INIS)

    1982-08-01

    This report examined specific functional components of the routine external personnel dosimeter program at Hanford. Components studied included: dosimeter readout; dosimeter calibration; dosimeter field response; dose calibration algorithm; dosimeter design; and TLD chip acceptance procedures. Additional information is also presented regarding the dosimeter response to light- and medium-filtered x-rays, high energy photons and neutrons. This study was conducted to clarify certain data obtained during the FY-1980 studies

  3. The active personnel dosimeter---APFEL enterprises superheated drop detector

    International Nuclear Information System (INIS)

    Ipe, N.E.; Donahue, R.J.; Busick, D.D.

    1991-03-01

    The Active Personnel Dosimeter (APD) provides a digital readout of events caused by neutrons interacting with superheated liquid droplets. The droplets are suspended in a gel held in a replaceable cartridge. Upon neutron interaction, the superheated droplet vaporizes, forming a bubble. The sound produced in this process is recorded by transducers that sense the accompanying pressure pulse. The APD electronically discriminates against spurious noise and vibration. Studies with the production prototype APDs indicate that the detector response is linear up to about 0.40 mSv, with large variations sometimes from predicted values and between cartridges at higher dose equivalents. The response to standard neutron sources (bare 252 Cf, PuBe, PuB, PuF, PuLi) is reported and compared with the expected response. Unirradiated cartridges self-nucleate when heated to temperatures of 46 degrees C. The APD is insensitive to low-energy photons but responds to high-energy photons and electrons. 8 refs., 2 figs., 3 tabs

  4. LOW-COST PERSONNEL DOSIMETER.

    Science.gov (United States)

    specification was achieved by simplifying and improving the basic Bendix dosimeter design, using plastics for component parts, minimizing direct labor, and making the instrument suitable for automated processing and assembly. (Author)

  5. The LLNL CR-39 personnel neutron dosimeter

    International Nuclear Information System (INIS)

    Hankins, D.E.; Homann, S.; Westermark, J.

    1987-01-01

    We developed a personnel neutron dosimetry system based on the electrochemical etching of CR-39 plastic at elevated temperatures. The doses obtained using this dosimeter system are more accurate than those obtained using other dosimetry systems, especially when varied neutron spectra are encountered. This CR-39 dosimetry system does not have the severe energy dependence that exists with albedo neutron dosimeters or the fading and reading problems encountered with NTA film. 3 refs., 4 figs

  6. Automating the personnel dosimeter monitoring program

    International Nuclear Information System (INIS)

    Compston, M.W.

    1982-12-01

    The personnel dosimetry monitoring program at the Portsmouth uranium enrichment facility has been improved by using thermoluminescent dosimetry to monitor for ionizing radiation exposure, and by automating most of the operations and all of the associated information handling. A thermoluminescent dosimeter (TLD) card, worn by personnel inside security badges, stores the energy of ionizing radiation. The dosimeters are changed-out periodically and are loaded 150 cards at a time into an automated reader-processor. The resulting data is recorded and filed into a useful form by computer programming developed for this purpose

  7. Intercomparison of high energy neutron personnel dosimeters

    International Nuclear Information System (INIS)

    McDonald, J.C.; Akabani, G.; Loesch, R.M.

    1993-03-01

    An intercomparison of high-energy neutron personnel dosimeters was performed to evaluate the uniformity of the response characteristics of typical neutron dosimeters presently in use at US Department of Energy (DOE) accelerator facilities. It was necessary to perform an intercomparison because there are no national or international standards for high-energy neutron dosimetry. The testing that is presently under way for the Department of Energy Laboratory Accreditation Program (DOELAP) is limited to the use of neutron sources that range in energy from about 1 keV to 2 MeV. Therefore, the high-energy neutron dosimeters presently in use at DOE accelerator facilities are not being tested effectively. This intercomparison employed neutrons produced by the 9 Be(p,n) 9 B interaction at the University of Washington cyclotron, using 50-MeV protons. The resulting neutron energy spectrum extended to a maximum of approximately 50-MeV, with a mean energy of about 20-MeV. Intercomparison results for currently used dosimeters, including Nuclear Type A (NTA) film, thermoluminescent dosimeter (TLD)-albedo, and track-etch dosimeters (TEDs), indicated a wide variation in response to identical doses of high-energy neutrons. Results of this study will be discussed along with a description of plans for future work

  8. A pocket type thermoluminescent personnel dosimeter

    International Nuclear Information System (INIS)

    Vora, K.G.; Nagpal, J.S.; Pendurkar, H.K.; Gangadharan, P.

    1979-01-01

    A pocket type thermoluminescent personnel dosemeter using CaSO 4 : Dy phosphor is described. Two glass capillaries containing the phosphor are fitted into a plastic tube and covered by a cylindrical filter. The combination is fitted into an ink barrel of a fountain pen. The response of this Dy glass dosimeter was studied for various incident photon energies. A uniform response over the energy range from 33 keV to 1250 keV is achieved. (A.K.)

  9. Guidelines for the calibration of personnel dosimeters

    International Nuclear Information System (INIS)

    Roberson, P.L.; Holbrook, K.L.

    1984-01-01

    This guide describes minimum acceptable performance levels for personnel dosimetry systems used at Department of Energy (DOE) facilities. The goal is to improve both the quality of radiological calibrations and the methods of comparing reported occupational doses between DOE facilities. Reference calibration techniques are defined. A standard for evaluation of personnel dosimetry systems and recommended design parameters for personnel dosimeters are also included. Approximate intervals for the radiation energies for which these guidelines are appropriate are 15 keV to 2 MeV for photons; above 0.3 MeV for beta particles; and 1 keV to 2 MeV for neutrons. An analysis of ANSI N13.11 was completed using performance evaluations of selected personnel dosimetry systems in use at DOE facilities. The results of this analysis are incorporated in the guidelines

  10. Response characteristics of selected personnel neutron dosimeters

    International Nuclear Information System (INIS)

    McDonald, J.C.; Fix, J.J.; Hadley, R.T.; Holbrook, K.L.; Yoder, R.C.; Roberson, P.L.; Endres, G.W.R.; Nichols, L.L.; Schwartz, R.B.

    1983-09-01

    Performance characteristics of selected personnel neutron dosimeters in current use at Department of Energy (DOE) facilities were determined from their evaluation of neutron dose equivalent received after irradiations with specific neutron sources at either the National Bureau of Standards (NBS) or the Pacific Northwest Laboratory (PNL). The characteristics assessed included: lower detection level, energy response, precision and accuracy. It was found that when all of the laboratories employed a common set of calibrations, the overall accuracy was approximately +-20%, which is within uncertainty expected for these dosimeters. For doses above 80 mrem, the accuracy improved to better than 10% when a common calibration was used. Individual differences found in this study may reflect differences in calibration technique rather than differences in the dose rates of actual calibration standards. Second, at dose rates above 100 mrem, the precision for the best participants was generally below +-10% which is also within expected limits for these types of dosimeters. The poorest results had a standard deviation of about +-25%. At the lowest doses, which were sometimes below the lower detection limit, the precision often approached or exceeded +-100%. Third, the lower level of detection for free field 252 Cf neutrons generally ranged between 20 and 50 mrem. Fourth, the energy dependence study provided a characterization of the response of the dosimeters to neutron energies far from the calibration energy. 11 references, 22 figures, 26 tables

  11. Energy response study of modified CR-39 neutron personnel dosimeter

    International Nuclear Information System (INIS)

    Sathian, Deepa; Bakshi, A.K.; Datta, D.; Nair, Sreejith S.; Sathian, V.; Mishra, Jitendra; Sen, Meghnath

    2018-01-01

    Personnel neutron dosimetry is an integral part of radiation protection. No single dosimeter provides the satisfactory energy response, sensitivity, angular dependence characteristics and accuracy necessary to meet the requirement of an ideal personnel neutron dosimeter. The response of a personnel neutron dosimeter is critically dependent upon the energy distribution of the neutron field. CR-39 personnel neutron dosimeters were typically calibrated in the standard neutron field of 252 Cf and 241 Am-Be in our laboratory, although actual neutron fields may vary from the calibration neutron spectrum. Recently the badge cassette of the personnel neutron dosimeter was changed due to frequent damage of the PVC badge used earlier. This paper discusses energy response of CR-39 solid state nuclear track detector loaded in this modified badge cassette as per latest ISO recommendation

  12. Personnel neutron dosimeter evaluation and upgrade program

    International Nuclear Information System (INIS)

    Fix, J.J.; Brackenbush, L.W.; McDonald, J.C.; Roberson, P.L.; Holbrook, K.L.; Endres, G.W.R.; Faust, L.G.

    1983-01-01

    Evaluation of neutron dosimeters from twelve DOE laboratories involved about 2500 dosimeter irradiations at both PNL and the National Bureau of Standards (NBS) using neutrons of several energies and doses and several irradiations for good statistical analysis. The data and their analyses will be published later. The information evaluates accuracy, precision, lower dose detection, and energy response of dosimeters

  13. Site-specific calibration of the Hanford personnel neutron dosimeter

    International Nuclear Information System (INIS)

    Endres, A.W.; Brackenbush, L.W.; Baumgartner, W.V.; Rathbone, B.A.

    1994-10-01

    A new personnel dosimetry system, employing a standard Hanford thermoluminescent dosimeter (TLD) and a combination dosimeter with both CR-39 nuclear track and TLD-albedo elements, is being implemented at Hanford. Measurements were made in workplace environments in order to verify the accuracy of the system and establish site-specific factors to account for the differences in dosimeter response between the workplace and calibration laboratory. Neutron measurements were performed using sources at Hanford's Plutonium Finishing Plant under high-scatter conditions to calibrate the new neutron dosimeter design to site-specific neutron spectra. The dosimeter was also calibrated using bare and moderated 252 Cf sources under low-scatter conditions available in the Hanford Calibration Laboratory. Dose equivalent rates in the workplace were calculated from spectrometer measurements using tissue equivalent proportional counter (TEPC) and multisphere spectrometers. The accuracy of the spectrometers was verified by measurements on neutron sources with calibrations directly traceable to the National Institute of Standards and Technology (NIST)

  14. Personnel neutron dosimeter for use in a plutonium processing plant

    International Nuclear Information System (INIS)

    Brunskill, R.T.; Hwang, F.S.W.

    1978-01-01

    A thermoluminesence dosimeter for personnel neutron dose measurement, which is based on the albedo principle, has been developed at Windscale works. The dosimeter has been calibrated against a 238 Pu/Be neutron source using different degrees of moderation and against a variety of neutron spectra prevailing in different areas of the Plutonium Finishing Plant. The dosimeter consists of two identical parts in which the sensitive elements are graphite discs which have thermoluminescent crystals sealed to the plane faces with a high temperature resin. The graphite discs are supported in teflon washers which fit into a body of tufnol. A circular insert of boronated polythene in each tufnol body provides a thermal neutron absorber for the sensitive element in the other half of the dosimeter. Natural lithium borate was used as the neutron sensitive phosphor and a lithium borate made from isotopes 7 Li (99.9%) and 11 B (99.2%) as the neutron insensitive materials. Neutron-sensitive lithium borate is sealed to one face of each disc and the neutron-insensitive material to the opposite face. The dosimeter is so assembled that the neutron-sensitive faces both lie in the central plane. The design is such that one neutron sensitive face responds to the incident flux of neutron only while the other responds to the albedo flux

  15. VALIDATION OF HANFORD PERSONNEL AND EXTREMITY DOSIMETERS IN PLUTONIUM ENVIRONMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Scherpelz, Robert I.; Fix, John J.; Rathbone, Bruce A.

    2000-02-10

    A study was performed in the Plutonium Finishing Plant to assess the performance of Hanford personnel neutron dosimetry. The study was assessed whole body dosimetry and extremity dosimetry performance. For both parts of the study, the TEPC was used as the principle instrument for characterizing workplace neutron fields. In the whole body study, 12.7-cm-diameter TEPCs were used in ten different locations in the facility. TLD and TED personnel dosimeters were exposed on a water-filled phantom to enable a comparison of TEPC and dosimeter response. In the extremity study, 1.27-cm-diameter TEPCs were exposed inside the fingers of a gloveboxe glove. Extremity dosimeters were wrapped around the TEPCs. The glove was then exposed to six different cans of plutonium, simulating the exposure that a worker's fingers would receive in a glovebox. The comparison of TEPC-measured neutron dose equivalent to TLD-measured gamma dose equivalent provided neutron-to-gamma ratios that can be used to estimate the neutron dose equivalent received by a worker's finger based on the gamma readings of an extremity dosimeter. The study also utilized a Snoopy and detectors based on bubble technology for assessing neutron exposures, providing a comparison of the effectiveness of these instruments for workplace monitoring. The study concludes that the TLD component of the HCND performs adequately overall, with a positive bias of 30%, but exhibits excessive variability in individual results due to instabilities in the algorithm. The TED response was less variable but only 20% of the TEPC reference dose on average because of the low neutron energies involved. The neutron response of the HSD was more variable than the TLD component of the HCND and biased high by a factor of 8 overall due to its calibration to unmoderated 252Cf. The study recommends further work to correct instabilities in the HCND algorithm and to explore the potential shown by the bubble-based dosimeters.

  16. Description and evaluation of the Hanford personnel dosimeter program from 1944 through 1989. [Contain Glossary

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, R.H.; Fix, J.J.; Baumgartner, W.V.; Nichols, L.L.

    1990-09-01

    This report describes the evolution of personnel dosimeter technology at Hanford since the inception of Hanford operations in 1944. Each of the personnel dosimeter systems used by people working or visiting Hanford is described. In addition, the procedures used to calibrate and calculate dose for each of the dosimeter systems are described. The accuracy of the recorded dose, primarily whole body deep dose, for the different dosimeter systems is evaluated. The evaluation is based on an extensive review of historical literature, as well as a 1989 intercomparison study of all film dosimeters and performance testing of the thermoluminescent dosimeter, also conducted during 1989. 73 refs., 40 figs., 41 tabs.

  17. Hanford beta-gamma personnel dosimeter prototypes and evaluation

    International Nuclear Information System (INIS)

    Fix, J.J.; Holbrook, K.L.; Soldat, K.L.

    1983-04-01

    Upgraded and modified Hanford dosimeter prototypes were evaluated for possible use at Hanford as a primary beta-gamma dosimeter. All prototypes were compatible with the current dosimeter card and holder design, as well as processing with the automated Hanford readers. Shallow- and deep-dose response was determined for selected prototypes using several beta sources, K-fluorescent x rays and filtered x-ray techniques. All prototypes included a neutron sensitive chip. A progressive evaluation of the performance of each of the upgrades to the current dosimeter is described. In general, the performance of the current dosimeter can be upgraded using individual chip sensitivity factors to improve precision and an improved algorithm to minimize bias. The performance of this dosimeter would be adequate to pass all categories of the ANSI N13.11 performance criteria for dosimeter procesors, provided calibration techniques compatible with irradiations adopted in the standard were conducted. The existing neutron capability of the dosimeter could be retained. Better dosimeter performance to beta-gamma radiation can be achieved by modifying the Hanford dosimeter so that four of the five chip positions are devoted to calculating these doses instead of the currently used two chip positions. A neutron sensitive chip was used in the 5th chip position, but all modified dosimeter prototypes would be incapable of discriminating between thermal and epithermal neutrons. An improved low energy beta response can be achieved for the current dosimeter and all prototypes considered by eliminating the security credential. Further improvement can be obtained by incorporating the 15-mil thick TLD-700 chips

  18. Personnel radiation dosimetry laboratory accreditation programme for thermoluminescent dosimeters : a proposal

    International Nuclear Information System (INIS)

    Bhatt, B.C.; Srivastava, J.K.; Iyer, P.S.; Venkatraman, G.

    1993-01-01

    Accreditation for thermoluminescent dosimeters is the process of evaluating a programme intending to use TL personnel dosimeters to measure, report and record dose equivalents received by radiation workers. In order to test the technical competence for conducting personnel dosimetry service as well as to decentralize personnel monitoring service, it has been proposed by Radiological Physics Division (RPhD) to accredit some of the laboratories, in the country. The objectives of this accreditation programme are: (i) to give recognition to competent dosimetry processors, and (ii) to provide periodic evaluation of dosimetry processors, including review of internal quality assurance programme to improve the quality of personnel dosimetry processing. The scientific support for the accreditation programme will be provided by the scientific staff from Radiological Physics Division (RPhD) and Radiation Protection Services Division (RPSD). This paper describes operational and technical requirements for the Personnel Radiation Dosimetry Laboratory Accreditation Programme for Thermoluminescent Dosimeters for Personnel Dosimetry Processors. Besides, many technical documents dealing with the TL Personnel Dosimeter System have been prepared. (author). 5 refs., 2 figs

  19. Use of an albedo neutron personnel dosimeter for X- and γ-ray monitoring

    International Nuclear Information System (INIS)

    Gorbics, S.G.; Nash, A.E.; Johnson, T.L.

    1981-01-01

    With a judicious choice of cadmium filter size and thickness, it is possible to use the information from the 7 LiF detectors used in an albedo neutron personnel dosimeter to determine an individual's X-and γ-ray exposure, thus eliminating the need for a separate dosimeter for this purpose. A filter area of 400 mm 2 and a thickness of 0.51 mm is shown to be optimum for a simple, plastic, dosimeter design using detectors held in dental-film size cards. (author)

  20. Personnel monitoring system by thermoluminescence dosimeter - a study and review

    International Nuclear Information System (INIS)

    Iyer, V.S.; Alok, M.; Chandel, B.S.

    2018-01-01

    The principle objective of personnel monitoring system is to prevent overexposure and avoid unnecessary exposure of personnel working with various sources of radiation. The adequate system of personnel monitoring must provide for the measurement. evaluation and recording of significant doses accumulated by individuals together with a recording of conditions under which these doses are received

  1. Determination of personnel exposures in the lower energy ranges of X-ray by photographic dosimeter

    International Nuclear Information System (INIS)

    Ha, C.W.; Kim, J.R.; Suk, K.W.

    1986-01-01

    This paper described an improved technical method required for proper evaluation of personnel exposures by means of the photographic dosimeter developed by KAERI in lower gamma or X-ray energy regions, with which response of the dosimeter varies significantly. With calibration of the dosimeter in the energy range from 30 to 300 keV, the beam spectrum was carefully selected and specified it adequately. The absorber combinations and absorber thickness used to obtain the specified X-ray spectra from a constant potential X-ray machine were determined theoretically and also experimentally. A correlation between the density and exposure for the four separate energies, such as 49 keV eff , 154 keV eff 250 keV eff and 662 keV, is experimentally determined. As a result, it can be directly evaluated the exposure from the measured response of dosimeter. (Author)

  2. The accreditation programs and proficiency test in Taiwan for personnel dosimeter services (1991-1998)

    International Nuclear Information System (INIS)

    Lee, B.T.; Hwang, W.S.; Su, S.H.

    2000-01-01

    According to the ionizing radiation safety regulation approved by the ROC Atomic Energy Council (AEC), personnel dosimeter processors shall be accredited by the Chinese National Laboratory Accreditation (CNLA) program before offering dosimeter services and shall be accredited every two years (now has been rescheduled to be every three years since 1996). The aim of this program is to secure quality and technical capability of personnel dosimeters, and to provide systematic improvement for the internal calibration and testing laboratory applying for accreditation by means of assessment procedures. The criteria used to evaluate the capability at laboratories are ISO/IEC 25 (1990) and technical guide in different accreditation fields. The Institute of Nuclear Energy Research (INER) was entrusted by CNLA as the central laboratory to perform the proficiency test of personnel dosimeters for laboratory accreditation in December 1990. Such proficiency tests, based on ANSI N13.11 (1983), which is mainly separated to accident categories and protection categories which consists of eight parts of tests including single and mixture radiation of x-ray, gamma, beta and neutron, have been conducted four times, in 1991, 1993, 1995 and 1998. This paper deals with the test procedures and results of proficiency tests of personnel dosimeters from 1991 until 1998. The results of the four proficiency tests showed that, for accident categories, the pass rate is about 91%; for protection categories, the pass rate is about 98%. Meanwhile, the central laboratory will adopt a new version of HPS N13.11 (1993) to replace ANSI N13.11 (1983) as new criteria for the next proficiency test to be conducted in 2001. (author)

  3. Design characteristics of a three-component AEOI Neutriran Albedo Neutron Personnel Dosimeter

    International Nuclear Information System (INIS)

    Sohrabi, M.; Katouzi, M.

    1991-01-01

    In establishing a national personnel neutron dosimetry service in Iran, different parameters of the AEOI Neutriran Albedo Neutron Personnel Dosimeter (NANPD) have been optimized. A NANPD was designed with three dosimetry components to measure (a) direct thermal neutrons, (b) direct fast neutrons and (C) direct neutrons by the detection of the albedo neutrons reflected from the body. The dosimeter consists of one or more Lexan polycarbonate and/or CR-39 foils and two 10 B (n,α) 7 Li converters in a cadmium cover so arranged as to efficiently measure the three neutron dose components separately. The boron converter thickness, its position relative to the beam direction and its distance from the PC foil were studied and the results were incorporated into the design. The dose response of the dosimeter, its lower detection limit as well as the correction factors related to the field neutrons and albedo neutrons were also determined for a 238 Pu-Be, an 241 Am-Be and a 252 Cf sources. In this paper, the dosimeter design and its dosimetric characteristics are presented and discussed. (author)

  4. Angular response characterization of the Martin Marietta Energy Systems, Inc., personnel dosimeter

    International Nuclear Information System (INIS)

    Ahmed, A.B.; McMahan, K.L.; Colwell, D.S.

    1993-08-01

    An evaluation of the Martin Marietta Energy Systems, Inc., personnel dosimeter to radiation incident from non-perpendicular angles was carried out to meet the Department of Energy Laboratory Accreditation Program (DOELAP) requirements. Dosimeters were exposed to six different radiation sources. For each source, dosimeters were rotated about their horizontal and vertical axes at seven different angles each. Raw readings were processed through the dose calculation algorithm used for routine personnel dosimetry to determine dose equivalent values. Dose equivalent responses relative to zero degree incident angle were found to be within ± 20% for M150, K-59 and 137 Cs photons when the incident angle was 60 degree or less. For low-energy photon irradiations (M30 and K-16), responses for angles other than perpendicular incidence are generally unpredictable. Reasons include: (1) failure of dose calculation algorithm to identify the radiation field correctly due to unusual element ratios; and (2) at extreme angles (± 85 degree), the dosimeter design (in relation to the irradiation geometry) becomes the limiting factor in producing reproducible results. Response to 204 Tl beta particles decreases rapidly with increasing angle of incidence

  5. Some aspects of the use of proton recoil proportional counters for fast neutron personnel dosimeters

    International Nuclear Information System (INIS)

    Yule, T.J.; Bennett, E.F.

    1984-01-01

    Gas-filled proton recoil proportional counters have been used extensively for the measurement of neutron spectra in degraded fission-spectrum environments. Some considerations relating to the use of these counters for personnel dosimetry are here described. High sensitivity and good accuracy in the determination of dose-equivalent can be obtained if relatively high pressure hydrogen-filled proportional counters are used as the active element in a dosimeter system

  6. A quality control program for the thermoluminescence dosimeter (TLD) in personnel radiation monitoring

    International Nuclear Information System (INIS)

    Seo, Kyung Won; Kim, Jang Lyul; Lee, Sang Yoon; Lee, Hyung Sub

    1994-01-01

    High quality radiation dosimetry is essential for workers who rely upon personal dosemeters to record the amount of radiation to which they are exposed. The ministry of science and technology (MOST) issued a ministerial ordinance (No 199-15) about the technical criteria on personnel dosimeter processors on 1992. The purpose of this quality control program is to prescribe the procedures approved by the management of KAERI for implementing a quality badge service by means of TLD for personnel working in an area where they may be exposed to ionization radiation. (Author) 10 refs

  7. Evaluation of spurious readings in Los Alamos personnel TL dosimeters

    International Nuclear Information System (INIS)

    Eisen, Y.; Littlejohn, G.J.; Cortez, J.R.

    1984-08-01

    This study investigates the possibility of tritium build-up in TLD-600 chips irradiated with neutrons and the causes of spurious readings in the Harshaw TLD cards used for personnel dosimetry. Experiments indicated that spurious readings in TLD-600 chips, previously irradiated with neutrons, might occur in cases where the cards had been accidentally read at temperatures lower than 300 0 C as a result of bad contact between the hot finger in the reading system and the chips. Because a TLD card contains glue and paper bar-code labels, the postannealing is performed at 80 0 C for 17 hours. This annealing procedure alone does not effectively deplete the high-energy traps, such as those near 260 0 C, populated by high-LET (Linear Energy Transfer) particles. TLD-600 chips, irradiated on a phantom by 400 mrem of moderated fission neutrons, read at 240 0 C, annealed at 80 0 C for 17 hours, and then reread at 280 0 C, showed residual doses as large as 200 mrem (equivalent photons). Calculations and experiments show that for neutron exposures around 1 rem of moderated fission neutrons with an average energy of 500 keV, the maximum build-up of dose as a result of tritium formation is less than 1 mrem. The dose build-up in properly annealed TLD-600 and TLD-700 chips, is nearly the same, even though the TLD-600 chips were previously irradiated by neutrons. Both kinds of chips show natural background accumulation. A mechanism for annealing the Harshaw cards at high temperatures, without destroying the label or the adhesive material, was developed and found to be useful. 7 references, 4 figures, 3 tables

  8. Dosimeter

    International Nuclear Information System (INIS)

    Thomson, I.

    1986-01-01

    This invention relates to a dosimeter for measuring ionizing radiation, and particularly to a dosimeter using an insulated gate field effect transistor (IGFET) as a sensor, having substantially improved accuracy. An IGFET is a field effect transistor fabricated on a silicon substrate and having an oxide insulator between the gate electrode and the silicon substrate. The gate electrode can be either metal or polycrystalline silicon dioxide. This invention overcomes previously-noted problems with IGFET sensors - the variation of threshold voltage with temperature, their inherent zero offset which varies from wafer to wafer, and the zero drift in threshold voltage - by measuring the differential threshold between two IGFET sensors exposed to the same radiation, in which one is biased into its conducting region, and the other is biased either off or to a conducting level less than the first. The measured differential threshold voltage between the two transistors will be a measure of the gamma radiation dose

  9. Performance testing of personnel extremity dosimeters by Korean LiF: Mg, Cu, Na, Si TLD(KLT-300)

    International Nuclear Information System (INIS)

    Kim, J.L.; Lee, J.I.; Chang, S.Y.; Choi, H.S.; Lee, D.H.; Han, S.J.

    2005-01-01

    Full text: As the needs and opportunities for utilization of atomic energy and radiation are increasing, the related industries, medicines, environments are developing and the relevant organizations and companies are also becoming diverse. In result, the types and kinds of the radiation related to occupational environments are becoming diversified. For the whole body dosimeters, the methodology and criteria for the performance evaluation and safety regulations and laws have been prepared in some detail, but for the extremity dosimeters, those are not prepared yet in Korea. The extremity dosimeters are required when the extremity part of our body, such as hand, elbow, and arm below the elbow, the foot, knee, and leg below the knee are exposed to the radiation in specific work environments. The dosimeter irradiation conditions are clearly discriminated between the whole body exposure condition and the extremity exposure condition. By the investigation and analysis of the management status and dose evaluation methods of the extremity dosimeters for the local absorbed dose, the personnel monitoring system of the extremity dosimeter services in Korea can be diagnosed, and the performance testing criteria and procedures can be established. Therefore, this study presents the performance testing results of extremity dosimeters on the finger and arm/leg phantoms by the procedures recommended in the ANSI (American National Standard) N13.32 using KLT-300 TL materials (LiF:Mg,Cu,Nas,Si) which were developed in Korea Atomic Energy Research Institute (KAERI). The results show that the performance index for the two types of phantoms are sufficiently satisfied with the prescribed tolerance level in the all of the test categories listed in the ANSI N13.32. These results and procedures used in this study can be applicable for regulatory body to establish the standard criteria for acceptable performance and testing conditions for personnel extremity dosimeters services in the

  10. 1987 Neutron and gamma personnel dosimeter intercomparison study using a D2O-moderated 252Cf source

    International Nuclear Information System (INIS)

    Swaja, R.E.; West, L.E.; Sims, C.S.; Welty, T.J.

    1989-05-01

    The thirteenth Personnel Dosimetry Intercomparison Study (i.e., PDIS 13) was conducted during April 1987 as a joint effort by Oak Ridge National Laboratory's (ORNL) Dosimetry Applications Research Group and the Southwest Radiation Calibration Center at the University of Arkansas. A total of 48 organizations (34 from the US and 14 from abroad) participated in PDIS 13. Participants submitted a total of 1,113 neutron and gamma dosimeters for this mixed field study. The dosimeters were transferred by mail and were handled by experimental personnel at ORNL and the University of Arkansas. The type of neutron dosimeter and the percentage of participants submitting that type are as follows: TLD-albedo (49%), direct interaction TLD (31%), CR-39 (17%), film (3%). The type of gamma dosimeter and the percentage of participants submitting that type are as follows: Li 2 B 4 O 7 , alone or in combination with CaSO 4 , (69%), 7 LiF (28%), natural LiF (3%). Radiation exposures in PDIS 13 were limited to 0.5 and 1.5 mSv from 252 Cf moderated by 15-cm of D 2 O. Traditional exposures using the Health Physics Research Reactor (HPRR) were not possible due to the fact that all reactors at ORNL, including the HPRR, were shutdown by order of the Department of Energy at the time the intercomparison was performed. Planned exposures using a 238 PuBe source were negated by a faulty timing mechanism. Based on accuracy and precision, direct interaction TLD dosimeters exhibited the best performance in PDIS 13 neutron measurements. They were followed, in order of best performance, by CR-39, TLD albedo, and film. The Li 2 B 4 O 7 type TLD dosimeters exhibited the best performance in PDIS 13 gamma measurements. They were followed by natural LiF, 7 LiF, and film. 12 refs., 1 fig., 5 tabs

  11. Development of direct reading dosimeters for the dose 0-3 mSv and 0-5 mSv ranges for personnel monitoring

    International Nuclear Information System (INIS)

    Gaikwad, P.V.; Shirkar, Y.B.; Patil, A.S.; Madgaonkar, P.P.; Kale, K.L.; Guhagarkar, H.V.; Gandhi, D.P.; Gupta, S.K.; Kothiyal, G.P.; Sahni, V.C.

    1998-01-01

    Direct reading dosimeters (DRDs) are widely used to measure cumulative dose received by personnel working at nuclear reactor sites or in other environment having x- and gamma rays. A DRD operates on the principle of gold leaf electroscope, and is a small, rugged, hermetically sealed, self reading type device easily carried by an individual in his pocket. The development of dosimeters suitable for the dose ranges 0-3 mSv and 0-5 mSv is reported

  12. Evaluation of a thermoluminescent dosimeter for personnel monitoring in the nuclear-radiation environment

    International Nuclear Information System (INIS)

    Johnson, F.A.; McGowan, S.; Gravelle, R.A.

    1983-09-01

    Efforts to improve the responses of phosphor/polyethylene TLDs to neutrons in the 1-MeV range have been only partially successful. Some increases in response have resulted from reduction of phosphor grain size and substitution of CaSO 4 :Tm with CaF 2 :Mn or CaF 2 :Dy. Reasons for the continuing low response are not fully understood. Calculated responses of the TLDs, when located on the body, show a closer correlatin with the dose received by the bone marrow as a result of exposure to a weapon spectrum than is evident for the case of flat-response dosimeters. However the TLDs exhibit a greater difference in their response to a weapon spectrum as compared with that to a pure gamma spectrum than is the case for a flat-response dosimeter. The disparity becomes even larger when the dose measured by the dosimeters is expressed in terms of the biologically effective dose absorbed in the bone marrow. Investigation of the ability of a dosimeter, which is sensitive only to γ-rays, to provide a measure of the total bone marrow dose produced by a combined flux of γ-rays and neutrons, indicates that there is an unacceptable difference between the response to a pure gamma spectrum and that to a mixed spectrum from a weapon

  13. Response of combined albedo-track neutron personnel dosimeters behind IHEP proton synchrotron shielding

    International Nuclear Information System (INIS)

    Sannikov, A.V.; Korshunova, E.P.

    1989-01-01

    The method of readings interpretation of combined albedo-track neutron personnel dosemeters based on calculationsl analysis of the detector responses in various neutron spectra is described. The measurements of dose equivalent responses have been performed in various points behind IHEP proton synchrotron shielding. It is shown that CDs with fission track detectors have a small dose equivalent response dispersion behind IHEP proton synchrotron shielding, that shows the promise of their using for neutron personnel monitoring, that shows the promise of their using for neutron personnel monitoring at high energy accelerators. 16 refs.; 7 figs.; 3 tabs

  14. Personnel dose equivalent monitoring at SLAC using lithium-fluoride TLD's [thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    Jenkins, T.M.; Busick, D.D.

    1987-03-01

    TLD's replaced film badges in the early 1970's for all dose equivalent monitoring, both neutron and photon, and for all locations at SLAC. The photon TLD's, composed of Li-7 loaded teflon discs, are calibrated using conventional gamma-ray sources; i.e., Co-60, Cs-137, etc. For these TLD's a nominal value of 1 nC/mrem is used, and is independent of source energy for 100 keV to 3 MeV. Since measured dose equivalents at SLAC are only a small fraction of the allowable levels, it was not deemed necessary to develop neutron dosimeters which would measure dose equivalent accurately for all possible neutron spectra. Today, wallet TLD's, composed of pairs of Li-7 and Li-6 discs, are used, with the Li-6 measuring only thermal neutrons; i.e., they aren't moderated in any way to make them sensitive to neutrons with energies greater than thermal. The assumption is made that there is a correlation between thermal neutron fluences and fast neutron fluences around the research area where almost all neutron doses (exclusive of sealed sources) are received. The calibration factor for these Li-6 TLD's is 1 nC/mrem of fast neutrons. The method of determining the validity of this calibration is the subject of this note. 4 refs., 9 figs., 1 tab

  15. ON THE ADVISABILITY OF REJECTION OF SUBTRACTION OF BACKGROUND DOSIMETERS INDICATION VALUES FROM THE MEASURED VALUES OF INDIVIDUAL DOSES OF OCCUPATIONAL EXPOSURE OF A-GROUP PERSONNEL

    Directory of Open Access Journals (Sweden)

    A. N. Barkovskiy

    2013-01-01

    Full Text Available An article contains substantiation of advisability of rejection of subtraction of background dosimeters indication values from the measured values of individual doses of occupational exposure of A-group personnel in the process of carrying out of individual dosimetry control of medical organizations stuff which was implemented in the Methodical Guideline 2.6.1.3015-12. It is shown that mentioned procedure is firstly incorrect when we deal with low doses, when the impact of natural exposure could be really considerable and secondary senseless when we deal with dose values close to the dose limit value for A-group personnel when the impact of natural exposure is much lower then the error of measurements. It is suggested to carry out the account of the impact of natural exposure into personnel average doses basing on the analysis of statistical distributions of personnel individual doses and on indications of background dosimeters. It is suggested to add the information about indications of background dosimeters into the Base of Federal Statistical Supervision № 1-DOS as it is prescribed in the Methodical Guideline 2.6.1.3015-12. This article is the respond to the article of A.I. Grigoriev published in the present issue of Journal, in which the author contests the reasonableness of this provision.

  16. Magnetic field dosimeter development

    International Nuclear Information System (INIS)

    Lemon, D.K.; Skorpik, J.R.; Eick, J.L.

    1980-09-01

    In recent years there has been increased concern over potential health hazards related to exposure of personnel to magnetic fields. If exposure standards are to be established, then a means for measuring magnetic field dose must be available. To meet this need, the Department of Energy has funded development of prototype dosimeters at the Battelle Pacific Northwest Laboratory. This manual reviews the principle of operation of the dosimeter and also contains step-by-step instructions for its operation

  17. Personnel monitoring

    International Nuclear Information System (INIS)

    1965-01-01

    This film stresses the need for personnel monitoring in work areas where there is a hazard of exposure to radiation. It illustrates the use of personnel monitoring devices (specially the film dosimeter), the assessment of exposure to radiation and the detailed recording of the results on personnel filing cards

  18. Personnel monitoring

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1966-12-31

    This film stresses the need for personnel monitoring in work areas where there is a hazard of exposure to radiation. It illustrates the use of personnel monitoring devices (specially the film dosimeter), the assessment of exposure to radiation and the detailed recording of the results on personnel filing cards

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

    CERN Document Server

    Kaskanov, G Y

    2003-01-01

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

  20. Radiation dosimeter

    International Nuclear Information System (INIS)

    Lowe, D.

    1980-01-01

    A radiation dosimeter is described, comprising a thermoluminescent phosphor incorporated in matrix of polyethersulphone. The dosimeter is preferably a thin film formed by spreading a suspension of a powdered phosphor in a solution of polyethersulphone onto a flat surface. The solvent for the polyethersulphone is a mixture of a n-methyl-2-pyrrolidone and xylene in equal proportions. A thin, inert film of polyethersulphone can be cemented to one surface of the dosimeter so as to provide a skin dosimeter. (author)

  1. Plastic dosimeter

    International Nuclear Information System (INIS)

    Nagai, Shiro; Matsuda, Kohji.

    1988-01-01

    The report outlines major features and applications of plastic dosimeters. Some plastic dosimeters, including the CTA and PVC types, detect the response of the plastic material itself to radiations while others, such as pigment-added plastic dosimeters, contain additives as radiation detecting material. Most of these dosimeters make use of color centers produced in the dosimeter by radiations. The PMMA dosimeter is widely used in the field of radiation sterilization of food, feed and medical apparatus. The blue cellophane dosimeter is easy to handle if calibrated appropriately. The rad-color dosimeter serves to determine whether products have been irradiated appropriately. The CTA dosimeter has better damp proofing properties than the blue cellophane type. The pigment-added plastic dosimeter consists of a resin such as nylon, CTA or PVC that contains a dye. Some other plastic dosimeters are also described briefly. Though having many advantages, these plastic dosimeter have disadvantages as well. Some of their major disadvantages, including fading as well as large dependence on dose, temperature, humidity and anviroment, are discussed. (Nogami, K.)

  2. Kevlar® as a Potential Accident Radiation Dosimeter for First Responders, Law Enforcement and Military Personnel.

    Science.gov (United States)

    Romanyukha, Alexander; Trompier, François; Benevides, Luis A

    2016-08-01

    Today the armed forces and law enforcement personnel wear body armor, helmets, and flak jackets composed substantially of Kevlar® fiber to prevent bodily injury or death resulting from physical, ballistic, stab, and slash attacks. Therefore, there is a high probability that during a radiation accident or its aftermath, the Kevlar®-composed body armor will be irradiated. Preliminary study with samples of Kevlar® foundation fabric obtained from body armor used by the U.S. Marine Corps has shown that all samples evaluated demonstrated an EPR signal, and this signal increased with radiation dose. Based on these results, the authors predict that, with individual calibration, exposure at dose above 1 Gy can be reliably detected in Kevlar® samples obtained from body armor. As a result of these measurements, a post-event reconstruction of exposure dose can be obtained by taking various samples throughout the armor body and helmet worn by the same irradiated individual. The doses can be used to create a whole-body dose map that would be of vital importance in a case of a partial body or heterogeneous exposure.

  3. Pen dosimeters

    CERN Multimedia

    SC/RP Group

    2006-01-01

    The Radiation Protection Group has decided to withdraw all pen dosimeters from the main PS and SPS access points. This will be effective as of January 2006. The following changes will be implemented: All persons working in a limited-stay controlled radiation area must wear an operational dosimeter in addition to their personal DIS dosimeter. Any persons not equipped with this additional dosimeter must contact the SC/RP Group, which will make this type of dosimeter available for temporary loan. A notice giving the phone numbers of the SC/RP Group members to contact will be displayed at the former distribution points for the pen dosimeters. Thank you for your cooperation. The SC/RP Group

  4. Cell-phone interference with pocket dosimeters

    International Nuclear Information System (INIS)

    Djajaputra, David; Nehru, Ramasamy; Bruch, Philip M; Ayyangar, Komanduri M; Raman, Natarajan V; Enke, Charles A

    2005-01-01

    Accurate reporting of personal dose is required by regulation for hospital personnel that work with radioactive material. Pocket dosimeters are commonly used for monitoring this personal dose. We show that operating a cell phone in the vicinity of a pocket dosimeter can introduce large and erroneous readings of the dosimeter. This note reports a systematic study of this electromagnetic interference. We found that simple practical measures are enough to mitigate this problem, such as increasing the distance between the cell phone and the dosimeter or shielding the dosimeter, while maintaining its sensitivity to ionizing radiation, by placing it inside a common anti-static bag. (note)

  5. Cell-phone interference with pocket dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Djajaputra, David; Nehru, Ramasamy; Bruch, Philip M; Ayyangar, Komanduri M; Raman, Natarajan V; Enke, Charles A [Department of Radiation Oncology, University of Nebraska Medical Center, 987521 Nebraska Medical Center, Omaha, NE 68198-7521 (United States)

    2005-05-07

    Accurate reporting of personal dose is required by regulation for hospital personnel that work with radioactive material. Pocket dosimeters are commonly used for monitoring this personal dose. We show that operating a cell phone in the vicinity of a pocket dosimeter can introduce large and erroneous readings of the dosimeter. This note reports a systematic study of this electromagnetic interference. We found that simple practical measures are enough to mitigate this problem, such as increasing the distance between the cell phone and the dosimeter or shielding the dosimeter, while maintaining its sensitivity to ionizing radiation, by placing it inside a common anti-static bag. (note)

  6. Passive dosimeters other than film and TLDs [thermoluminescent dosimeter

    International Nuclear Information System (INIS)

    Hankins, D.E.

    1986-01-01

    This presentation will describe CR-39 plastic as a personnel neutron dosimeter. Recent research at LLNL and elsewhere has resulted in the development of a dosimetry system that is superior to any personnel neutron dosimeter previously available. The author describes the features of the dosimetry system and the new etching procedures and techniques in detail. Most of the research was done at the LLNL and has been supported as a part of the DOE Neutron Dosimetry Upgrade Program. 10 refs., 4 figs., 1 tab

  7. Neutron dosimeter

    International Nuclear Information System (INIS)

    Bartko, J.; Schoch, K.F. Jr.; Congedo, T.V.; Anderson, S.L. Jr.

    1989-01-01

    This patent describes a nuclear reactor. It comprises a reactor core; a thermal shield surrounding the reactor core; a pressure vessel surrounding the thermal shield; a neutron dosimeter positioned outside of the thermal shield, the neutron dosimeter comprising a layer of fissile material and a second layer made of a material having an electrical conductivity which permanently varies as a function of its cumulative ion radiation dose; and means, outside the pressure vessel and electrically connected to the layer of second material, for measuring electrical conductivity of the layer of second material

  8. Chemical dosimeter

    International Nuclear Information System (INIS)

    Baker, W.B.; Clark, D.G.

    1979-01-01

    The dosimeter may be carried by individuals e.g. at the belt and serves to monitor for vinyl-chloride vapors in industrial plants and for toxic radon gas and toxic radon gas products in mines. It contains a pump, sucking an air flow through an orifice and a filter, as well as a sensor circuit for detecting low air flow rates and a battery testing circuit. (DG) 891 HP/DG 892 MKO [de

  9. Composite material dosimeters

    Science.gov (United States)

    Miller, Steven D.

    1996-01-01

    The present invention is a composite material containing a mix of dosimeter material powder and a polymer powder wherein the polymer is transparent to the photon emission of the dosimeter material powder. By mixing dosimeter material powder with polymer powder, less dosimeter material is needed compared to a monolithic dosimeter material chip. Interrogation is done with excitation by visible light.

  10. Dose measurement during defectoscopic work using electronic personal dosimeters

    International Nuclear Information System (INIS)

    Smoldasova, J.

    2008-01-01

    Personal monitoring of the external radiation of radiation, personnel exposed to sources of ionizing radiation at a workplace is an important task of the radiological protection. Information based on the measured quantities characterizing the level of the exposure of radiation personnel enable to assess the optimum radiological protection at the relevant workplace and ascertain any deviation from the normal operation in time. Different types of personal dosimeters are used to monitor the external radiation of radiation personnel. Basically, there are two types of dosimeters, passive and active (electronic). Passive dosimeters provide information on the dose of exposure after its evaluation, while electronic dosimeters provide this information instantly. The goal of the work is to compare data acquired during different working activities using the DMC 2000 XB electronic dosimeters and the passive film dosimeters currently used at the defectoscopic workplace. (authors)

  11. APD arrays and large-area APDs via a new planar process

    CERN Document Server

    Farrell, R; Vanderpuye, K; Grazioso, R; Myers, R; Entine, G

    2000-01-01

    A fabrication process has been developed which allows the beveled-edge-type of avalanche photodiode (APD) to be made without the need for the artful bevel formation steps. This new process, applicable to both APD arrays and to discrete detectors, greatly simplifies manufacture and should lead to significant cost reduction for such photodetectors. This is achieved through a simple innovation that allows isolation around the device or array pixel to be brought into the plane of the surface of the silicon wafer, hence a planar process. A description of the new process is presented along with performance data for a variety of APD device and array configurations. APD array pixel gains in excess of 10 000 have been measured. Array pixel coincidence timing resolution of less than 5 ns has been demonstrated. An energy resolution of 6% for 662 keV gamma-rays using a CsI(T1) scintillator on a planar processed large-area APD has been recorded. Discrete APDs with active areas up to 13 cm sup 2 have been operated.

  12. Neutron dosimeter utilizing CR-39

    International Nuclear Information System (INIS)

    Souza, H.V.C. de.

    1991-05-01

    A personnel neutron dosimeter has been developed with discretization in a wide range of energies of real interest, utilizing the CR-39 polymer, to detect recoil protons in the fast range, and alpha particles in the thermal and epithermal ranges, with possibility to be disposed in the IRD/CNEN's conventional film badge suport. They are presented, abstractly, the difficulties and importance of the neutron dosimetry, beyond the general objectives that motivated this work execution. The details of the materials utilized in the dosimeter confection, and the experimental methodology employed to obtain the performance curves are presented. The results about linearity response of the dosimeter with respect to equivalent dose, in a wide range of doses, and about the verified angular dependence are analysed. (author)

  13. Optical dosimeter

    International Nuclear Information System (INIS)

    Drukaroff, I.; Fishman, R.

    1984-01-01

    A reflecting optical dosimeter is a thin block of optical material having an input light pipe at one corner and an output light pipe at another corner, arranged so that the light path includes several reflections off the edges of the block to thereby greatly extend its length. In a preferred embodiment, one corner of the block is formed at an angle so that after the light is reflected several times between two opposite edges, it is then reflected several more times between the other two edges

  14. Portable dosimeter

    International Nuclear Information System (INIS)

    Buffa, A.; Caley, R.; Pfaff, K.

    1986-01-01

    A simple but very accurate portable dosimeter is described for indicating the intensity of ionizing radiation, comprising, as a unit: (a) a radiation-detection chamber having a pair of parallel, facing, electrically-conducting, radiation-permeable electrodes spaced from each other to define a volume for a gas which is ionized by the radiation when exposed thereto; (b) electric potential supply means connected across the electrodes for attracting the gas ions to the electrodes and transferring their charge to the electrodes; (c) detection circuit means connected across the electrodes and having at least one of high-frequency electromagnetic- and radiation-sensitive components for detecting the charge on the electrodes and indicating therefrom a representation of the intensity of the radiation; (d) radiation shield means surrounding the radiation-sensitive components of the detection circuit means for shielding the latter from the ionizing radiation; (e) electric shield means surrounding the sensitive components of the detection circuit means for shielding the latter from electromagnetic interference including any caused by the ionizing radiation; and (f) ion shield means potting the ion-sensitive components for shielding them from radiation-caused ambient ionization; whereby the entire dosimeter may be assembled as the unit and portably transported into various radiation sources

  15. Radiation detectors for personnel monitoring - current developments and future trends

    International Nuclear Information System (INIS)

    Kannan, S.

    2003-01-01

    The radiation detectors for personnel monitoring range from the conventional passive dosimeters like the film badge and the TLD, to sophisticated active dosimeters for integrated gamma, beta and neutron dose measurement. With the availability of high accuracy active dosimeters, the process of personnel monitoring, acceptability among radiation workers, record keeping and dose control have become more simplified. However the high level of sophistication in the active dosimeter has its own inevitable price tag and the new breed of active dosimeters are prohibitively costly. The silver lining, in the otherwise dark cost scenario of these dosimeters is the potential for cost reduction at least in some of the dosimeters in the near future

  16. APD Properties and Recovery from Radiation Damage

    CERN Document Server

    Baccaro, Stefania; Caruso, S; Cavallari, Francesca; Dafinei, Ioan; Diemoz, Marcella; Emeliantchik, Igor; Festinesi, Armando; Longo, Egidio; Montecchi, Marco; Organtini, Giovanni; Rosi, G

    1997-01-01

    Avalanche photodiodes will be used to detect scintillation light from PWO crystals in the CMS electromagnetic calorimeter. Properties of Hamamatsu APD are reported special attention has been devoted to the study of radiation hardness and room temperature annealing. We found a fast recovery with a time constant of 1.3 days a medium fast recovery with a lifetime of the order of 10 days and indication of a third component with very long time constant of the order of 300 days.

  17. LLL development of a combined etch track: albedo dosimeter

    International Nuclear Information System (INIS)

    Griffith, R.V.; Fisher, J.C.; Harder, C.A.

    1977-01-01

    The addition of polycarbonate sheet to albedo detectors for electrochemical etching provides a simple, inexpensive way to reduce the spectral sensitivity of the personnel dosimeter without losing the albedo features of sensitivity and ease of automation. The ECEP technique also provides the dosimetrist with the potential for identifying conditions of body orientation that might otherwise lead to significant error in dosimeter evaluation

  18. Scintillation counter with MRS APD light readout

    International Nuclear Information System (INIS)

    Akindinov, A.; Bondarenko, G.; Golovin, V.; Grigoriev, E.; Grishuk, Yu.; Mal'kevich, D.; Martemiyanov, A.; Ryabinin, M.; Smirnitskiy, A.; Voloshin, K.

    2005-01-01

    START, a high-efficiency and low-noise scintillation detector for ionizing particles, was developed for the purpose of creating a high-granular system for triggering cosmic muons. Scintillation light in START is detected by MRS APDs (Avalanche Photo-Diodes with Metal-Resistance-Semiconductor Structure), operated in the Geiger mode, which have 1mm 2 sensitive areas. START is assembled from a 15x15x1cm 3 scintillating plastic plate, two MRS APDs and two pieces of wavelength-shifting optical fiber stacked in circular coils inside the plastic. The front-end electronic card is mounted directly on the detector. Tests with START have confirmed its operational consistency, over 99% efficiency of MIP registration and good homogeneity. START demonstrates a low intrinsic noise of about 10 -2 Hz. If these detectors are to be mass-produced, the cost of a mosaic array of STARTs is estimated at a moderate level of 2-3kUSD/m 2

  19. Radiation dosimeter utilizing the thermoluminescence of lithium fluoride.

    Science.gov (United States)

    CAMERON, J R; DANIELS, F; JOHNSON, N; KENNEY, G

    1961-08-04

    A dosimeter, with little wavelength dependence and large useful energy range for electromagnetic radiation, which is simple to use and read, has been developed. It appears to have applications in personnel monitoring as well as radiation research.

  20. Intercomparison of personal dose equivalent measurements by active personal dosimeters. Final report of a joint IAEA-EURADOS project

    International Nuclear Information System (INIS)

    2007-11-01

    Active personal dosimeters (APD) are widely used in many countries, i.e. in the medical field and as operational dosimeters in nuclear power plants. Their use as legal dosimeters is already established in a few countries, and will increase in the near future. In the majority of countries, APDs have not undergone accreditation programmes or intercomparisons. In 2001, an EURADOS (European Radiation Dosimetry Group) Working Group on harmonization of individual monitoring was formed, funded by the European Commission, in the fifth framework programme, and by the participating institutes. The work addressed four issues; inter alia also an inventory of new developments in individual monitoring with an emphasis on the possibilities and performance of active (electronic) dosimeters for both photon/beta and neutron dosimetry. Within the work on this issue, a catalogue of the most extensively used active personal dosimeters (APDs) suitable for individual monitoring was made. On the basis of the knowledge gained in this activity, the organization of an international intercomparison, which would address APDs, was considered of great value to the dosimetric community. The IAEA in cooperation with EURADOS organized such an intercomparison in which most of the testing criteria as described in two internationally accepted standards (IEC61526 and IEC61283) were used. Additionally, simulated workplace fields were used for testing the APD reactions to pulsed X ray fields and mixed gamma/X ray fields. This is the first time that results of comparisons of such types are published, which is of great importance for APD end users in medical diagnostic and surgery X ray applications. Nine suppliers from six countries in Europe and the USA participated in the intercomparison with 13 different models. One of the models was a special design for extremity dose measurements. Irradiations and readout was done by two accredited calibration laboratories in Belgium and France and the French

  1. Personnel Dosimeters with Radiation Elements; Dosimetres Individuels Comportant des Elements Emetteurs; 0418 041d 0414 0418 0412 0418 0414 ; Dosimetros Individuales Provistos de Elementos Emisores

    Energy Technology Data Exchange (ETDEWEB)

    Hosemann, R.; Warrikhoff, H. F.H. [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin-Dahlem, Federal Republic of Germany (Germany)

    1965-06-15

    The radiation element is a vacuum diode, the electrodes of which emit a different charge of electrons per unit of irradiation. Since the electrons ejected leave one electrode with a high energy, the other electrode will be charged to proportionally high voltages without any auxiliary power. Accordingly these direct reading systems are called radiation elements. When measuring X- and y-rays, one electrode consists of lead, the other of carbon. The wavelength independence with regard to the r-unit was obtained by the electron-filtering method. The sensitivity is approximately 0.5 V/r {+-} 8% within the range from 80 keV to 1.25 MeV. (Full scale 200-2000 r either linear or quasi logarithm. ) When measuring slow and fast neutrons, the induced {beta}-activity of the electrodes charge the built-in electrometer. It is possible to measure both gamma radiation and neutrons in rem units with one instrument. The neutron sensitivity of a gamma element can be made definitely zero, but the gamma sensitivity of a neutron element presents some difficulties. The outstanding advantages of these instruments are: (1) Self-powered systems, always ready to function, unlimited storing time, no batteries or charging units; (2) Extremely low fading because of the use of vacuum and quartz for isolation; (3) Quantitative measurement of the highest attainable dose rates because of no recombination effects (vacuum) ; and (4) Either direct or indirect systems. The direct reading instrument contains the radiation element and the electrometer in the same vacuum vessel. There are no electrical contacts outside the instrument. Cylindrical and spherical designs of the element are preferable to other geometries. The outer dimensions of the instrument will be the same as those of the commonly used pen-type dosimeters. Each system contains a discharge switch and a control unit. (author) [French] L'element emetteur est constitue par une diode a vide dont les electrodes emettent des flux d

  2. Electret dosimeter utilizing gas multiplication

    International Nuclear Information System (INIS)

    Ikeya, M.; Miki, T.

    1980-01-01

    It was found that the high electric field around the surface of an electret leads to cascade multiplication of the ionization process in a surrounding gas. Very sensitive charge decay constants of the order of 1mrad, were obtained for electrets composed of polyvinyliden fluoride or teflon polymers. The reduced charge is stable and can be utilized in personnel dosimetry. A simple pocket chamber dosimeter is described consisting of a small speaker or buzzer, a cylindrical chamber filled with air, argon or other gases, a polymer thermoelectret foil and an electrode. The sonic vibration of the foil induces an alternating charge on the electrode which is amplified and detected. The feasibility of this dosimeter and its shock and vibration resistance have been demonstrated. (author)

  3. US progress on the development of CR-39 based neutron dosimeters

    International Nuclear Information System (INIS)

    Hadlock, D.E.

    1987-06-01

    Historically at US nuclear facilities, two types of personnel neutron dosimeters have been in routine use: nuclear track emulsion-Type A (NTA) film and thermoluminescent dosimeter (TLD)-albedo. Both of these dosimeters have energy-dependent responses. Therefore, the neutron energy spectra must be known, to interpret the dosimeter results properly. A new state-of-the-art dosimetry system has been developed within the US Department of Energy (US DOE) Personnel Neutron Dosimeter Evaluation and Upgrade Program. This system is called the combination thermoluminescent dosimeter/track etch dosimeter (TLD/TED). This paper briefly describes US DOE research currently being conducted to further enhance the TED portion of the combination TLD/TED system. The research areas involved include dose sensitivity, neutron energy range, specialized radiators, self-developing dosimeters, and neutron spectrometry. 1 fig., 1 tab

  4. G-APDs in Cherenkov astronomy: The FACT camera

    International Nuclear Information System (INIS)

    Krähenbühl, T.; Anderhub, H.; Backes, M.; Biland, A.; Boller, A.; Braun, I.; Bretz, T.; Commichau, V.; Djambazov, L.; Dorner, D.; Farnier, C.; Gendotti, A.; Grimm, O.; Gunten, H. von; Hildebrand, D.; Horisberger, U.; Huber, B.; Kim, K.-S.; Köhne, J.-H.; Krumm, B.

    2012-01-01

    Geiger-mode avalanche photodiodes (G-APD, SiPM) are a much discussed alternative to photomultiplier tubes in Cherenkov astronomy. The First G-APD Cherenkov Telescope (FACT) collaboration builds a camera based on a hexagonal array of 1440 G-APDs and has now finalized its construction phase. A light-collecting solid PMMA cone is glued to each G-APD to eliminate dead space between the G-APDs by increasing the active area, and to restrict the light collection angle of the sensor to the reflector area in order to reduce the amount of background light. The processing of the signals is integrated in the camera and includes the digitization using the domino ring sampling chip DRS4.

  5. Remeasurement of early Harwell personnel film dosimeters

    International Nuclear Information System (INIS)

    Smith, J.W.; McGuinness, E.A.

    1981-05-01

    The A.E.A. epidemiological study depends for its radiation dose data on records of film badge doses which have been stored continuously since 1947. The records were originally kept to assist in the control of radiation hazard to the individual and for that purpose doses below the measurement threshold were unimportant. The epidemiological study could consider these doses to be either zero or equal to the measurement threshold, but both assumptions risk introducing a bias. Samples of old films worn in 1955 and 1960 were therefore remeasured using the present-day lower threshold of 0.005 rems to aid the choice of the most correct estimate. It was found that there had been little change in the blackening on the films or in the assessed radiation dose for 238 films above the original threshold of 0.05 rems, confirming that remeasurement was possible. The 2426 films previously recorded as ''<0.05 rems'' were found on remeasurement to give an average dose of 0.009 rems. A similar epidemiological study of radiation workers at Hanford took threshold doses as equal to zero and considered only positive measured doses. The errors possible with this approach are discussed. (author)

  6. Dosimeter charging apparatus

    International Nuclear Information System (INIS)

    Reuter, F.A.; Moorman, Ch.J.

    1985-01-01

    An apparatus for charging a dosimeter which has a capacitor connected between first and second electrodes and a movable electrode in a chamber electrically connected to the first electrode. The movable electrode deflects varying amounts depending upon the charge present on said capacitor. The charger apparatus includes first and second charger electrodes couplable to the first and second dosimeter electrodes. To charge the dosimeter, it is urged downwardly into a charging socket on the charger apparatus. The second dosimeter electrode, which is the dosimeter housing, is electrically coupled to the second charger electrode through a conductive ring which is urged upwardly by a spring. As the dosimeter is urged into the socket, the ring moves downwardly, in contact with the second charger electrode. As the dosimeter is further urged downwardly, the first dosimeter electrode and first charger electrode contact one another, and an insulator post carrying the first and second charger electrodes is urged downwardly. Downward movement of the post effects the application of a charging potential between the first and second charger electrodes. After the charging potential has been applied, the dosimeter is moved further into the charging socket against the force of a relatively heavy biasing spring until the dosimeter reaches a mechanical stop in the charging socket

  7. Personnel dose assignment practices

    International Nuclear Information System (INIS)

    Fix, J.J.

    1993-04-01

    Implementation of DOE N 5480.6 Radiological Control Manual Article 511(3) requirements, to minimize the assignment of personnel dosimeters, should be done only under a broader context ensuring that capabilities are in place to monitor and record personnel exposure both for compliance and for potential litigation. As noted in NCRP Report No. 114, personnel dosimetry programs are conducted to meet four major objectives: radiation safety program control and evaluation; regulatory compliance; epidemiological research; and litigation. A change to Article 511(3) is proposed that would require that minimizing the assignment of personnel dosimeters take place only following full evaluation of overall capabilities (e.g., access control, area dosimetry, etc.) to meet the NCRP objectives

  8. Personnel radiation dosimetry

    International Nuclear Information System (INIS)

    1987-01-01

    The book contains the 21 technical papers presented at the Technical Committee Meeting to Elaborate Procedures and Data for the Intercomparison of Personnel Dosimeters organizaed by the IAEA on 22-26 April 1985. A separate abstract was prepared for each of these papers. A list of areas in which additional research and development work is needed and recommendations for an IAEA-sponsored intercomparison program on personnel dosimetry is also included

  9. Dosimeter design specifications

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The combination dosimeter and security credential holder was developed as part of the effort involved to provide an automated readout and thermoluminescent dosimetry capability at Hanford. The holder is designed to accomodate the thermoluminescent dosimeter card, appropriate filters, the security credential and a snap type clip. The body of the holder is ABS plastic (acrylontrile-butadiene-styrene). The dosimeter holder and card is mold casted providing uniformity of construction

  10. Optical Communications With A Geiger Mode APD Array

    Science.gov (United States)

    2016-02-09

    practical performance of a Geiger mode avalanche photodiode ( GM -APD, or Geiger mode APD) array for use in optical com- munications systems. I designed and...signal quality in the first half of the frame. These shorter reset times also did not offer any advantage in the maximum number of counts able to be...pattern was advantageous for the modifications being made in post-processing on the benchmark data. In particular, this allowed post-processing results

  11. APD detectors for biological fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Mazeres, S.; Borrel, V.; Magenc, C.; Courrech, J.L.; Bazer-Bachi, R.

    2006-01-01

    Fluorescence spectroscopy is a very convenient and widely used method for studying the molecular background of biological processes [L. Salome, J.L. Cazeil, A. Lopez, J.F. Tocanne, Eur. Biophys. J. 27 (1998) 391-402]. Chromophores are included in the structure under study and a flash of laser light induces fluorescence (Fluorescence Recovery After Photo-bleaching), the decay of which yields information on the polarity, the speed of rotation, and the speed of diffusion as well as on the temporal and spatial evolution of interactions between molecular species. The method can even be used to study living cells [J.F. Tocanne, L. Cezanne, A. Lopez, Prog. Lipid Res. 33 (1994) 203-237, L. Cezanne, A. Lopez, F. Loste, G. Parnaud, O. Saurel, P. Demange, J.F. Tocanne, Biochemistry 38 (1999) 2779-2786]. This is classically performed with a PM-based system. For biological reasons a decrease of the excitation of the cells is highly desirable. Because the fluorescence response then becomes fainter a significant improvement in detector capability would be welcome. We present here results obtained with an Avalanche Photo Diode (APD)-based system. The small sensitive area of detection allows a very significant improvement in signal/noise ratio, improvement in gain, and the opening-up of a new parameter space. With these new detectors we can begin the study of information transmission between cells through morphine receptors. This work involves both electronics engineers and biophysicists, so results and techniques in both fields will be presented here

  12. Thermoluminescent dosimeter system

    International Nuclear Information System (INIS)

    Felice, P.E.; Gonzalez, J.L.; Seidel, J.G.

    1979-01-01

    An improved thermoluminescent dosimeter system and apparatus for sensing alpha particle emission is described. A thermoluminescent body is sealed between a pair of metallized plastic films. The dosimeter is mounted within a protective inverted cup or a tube closed at one end, which is disposed in a test hole for exposure to radioactive radon gas which is indicaive of uranium deposits

  13. SDI-100 radiation dosimeter

    International Nuclear Information System (INIS)

    Zheng Zheng; Zhao Yongfu; Dai Honggui

    1995-01-01

    An intelligent radiation dosimeter, with such functions as signal collection and data processing, store, print and display, has been developed. Its detector is made of a micro-semiconductor. This dosimeter can be used in laboratories for agricultural 60 Co irradiators, radiotherapeutic facilities and other small and medium-size 60 Co irradiators

  14. Systematic approach to personnel neutron monitoring

    International Nuclear Information System (INIS)

    Griffith, R.V.; Hankins, D.E.

    1980-01-01

    NTA film and albedo detectors represent the major portion of personnel dosimeters now used for occupational neutron monitoring. However, recent attention to the spectral response of these systems has demonstrated the need for detectors that have a better match to the fields being monitored. Recent developments in direct recoil track etch dosimeters present some intriguing alternatives, and careful use of 237 Np fission fragment detectors offers the advantage of a good dose equivalent spectral match. Work continues on a number of other new detector mechanisms, but problems with sensitivity, energy response, gamma interference, etc., continue to prevent development of most mechanisms into viable personnel dosimeters. Current dosimeter limitations make a systematic approach to personnel neutron monitoring particularly important. Techniques have been developed and tested, using available portable survey instruments, that significantly improve the quality of dosimeter interpretation. Even simple spectrometry can be done with modest effort, significantly improving the health physicists ability to provide accurate neutron monitoring

  15. Passive radon daughter dosimeters

    International Nuclear Information System (INIS)

    McElroy, R.G.C.; Johnson, J.R.

    1986-03-01

    On the basis of an extensive review of the recent literature concerning passive radon daughter dosimeters, we have reached the following conclusions: 1) Passive dosimeters for measuring radon are available and reliable. 2) There does not presently exist an acceptable passive dosimeter for radon daughters. There is little if any hope for the development of such a device in the foreseeable future. 3) We are pessimistic about the potential of 'semi-passive dosimeters' but are less firm about stating categorically that these devices cannot be developed into a useful radon daughter dosimeter. This report documents and justifies these conclusions. It does not address the question of the worker's acceptance of these devices because at the present time, no device is sufficiently advanced for this question to be meaningful. 118 refs

  16. Modern methods of personnel dosimetry

    International Nuclear Information System (INIS)

    Kraus, W.; Herrmann, D.; Kiesewetter, W.

    The physical properties of radiation detectors for personnel dosimetry are described and compared. The suitability of different types of dosimeters for operational and central monitoring of normal occupational exposure, for accident and catastrophe dosimetry and for background and space-flight dosimetry is discussed. The difficulties in interpreting the dosimeter reading with respect to the dose in individual body organs are discussed briefly. 430 literature citations (up to Spring 1966) are given

  17. Testing limits to airflow perturbation device (APD measurements

    Directory of Open Access Journals (Sweden)

    Jamshidi Shaya

    2008-10-01

    Full Text Available Abstract Background The Airflow Perturbation Device (APD is a lightweight, portable device that can be used to measure total respiratory resistance as well as inhalation and exhalation resistances. There is a need to determine limits to the accuracy of APD measurements for different conditions likely to occur: leaks around the mouthpiece, use of an oronasal mask, and the addition of resistance in the respiratory system. Also, there is a need for resistance measurements in patients who are ventilated. Method Ten subjects between the ages of 18 and 35 were tested for each station in the experiment. The first station involved testing the effects of leaks of known sizes on APD measurements. The second station tested the use of an oronasal mask used in conjunction with the APD during nose and mouth breathing. The third station tested the effects of two different resistances added in series with the APD mouthpiece. The fourth station tested the usage of a flexible ventilator tube in conjunction with the APD. Results All leaks reduced APD resistance measurement values. Leaks represented by two 3.2 mm diameter tubes reduced measured resistance by about 10% (4.2 cmH2O·sec/L for control and 3.9 cm H2O·sec/L for the leak. This was not statistically significant. Larger leaks given by 4.8 and 6.4 mm tubes reduced measurements significantly (3.4 and 3.0 cm cmH2O·sec/L, respectively. Mouth resistance measured with a cardboard mouthpiece gave an APD measurement of 4.2 cm H2O·sec/L and mouth resistance measured with an oronasal mask was 4.5 cm H2O·sec/L; the two were not significantly different. Nose resistance measured with the oronasal mask was 7.6 cm H2O·sec/L. Adding airflow resistances of 1.12 and 2.10 cm H2O·sec/L to the breathing circuit between the mouth and APD yielded respiratory resistance values higher than the control by 0.7 and 2.0 cm H2O·sec/L. Although breathing through a 52 cm length of flexible ventilator tubing reduced the APD

  18. Alarm pocket dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, H; Kitamura, S [Matsushita Electric Industrial Co. Ltd., Kadoma, Osaka (Japan)

    1975-04-01

    This instrument is a highly reliable pocket dosimeter which has been developed for personal monitoring use. The dosimeter generates an alarm sound when the exposure dose reaches a preset value. Using a tiny GM tube for a radiation detector and measuring the integrated dose by means of a digital counting method, this new pocket dosimeter has high accuracy and stability. Using a sealed alkali storage battery for the power supply, and with an automatic control charger, this dosimetry system is easy and economical to operate and maintain. Detectable radiation by the dosimeter are X and ..gamma.. rays. Standard preset dose values are 30, 50, 80 and 100 mR. Detection accuracy is betwen +10% and -20%. The dosimeter is continuously usable for more than 14 hours after charging for 2 hours. The dosimeter has the following features; good realiability, shock-proof loud and clear alarm sound, the battery charger also serves as a stock container for the dosimeters, and no switching operation required for the power supply due to the internal automatic switch. Therefore, the dosimetry system is very useful for personal monitoring management in many radiation industry establishments.

  19. 10 CFR 36.55 - Personnel monitoring.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Personnel monitoring. 36.55 Section 36.55 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Operation of Irradiators § 36.55 Personnel monitoring. (a) Irradiator operators shall wear a personnel dosimeter that is...

  20. Evaluation of personal dosimeters

    International Nuclear Information System (INIS)

    Correa, C. A.

    2007-01-01

    This work makes a screening of the different types of dosimeters present in the international market, to provide operative dosimetry of individual monitoring to measure Hp(10) and Hp(0,07)-specifically for external radiation gamma and beta, as well as to give knowledge of advances of passive and operative dosimetry, and the changes in the regulatory policy relative to these aspects. The data has been extracted from several providers of dosimeters, and the importance has been stressed in a good election of the dosimeter before its use, as well as the important advances in these equipment. (Author) 14 refs

  1. DOI resolution measurement and error analysis with LYSO and APDs

    International Nuclear Information System (INIS)

    Lee, Chae-hun; Cho, Gyuseong

    2008-01-01

    Spatial resolution degradation in PET occurs at the edge of Field Of View (FOV) due to parallax error. To improve spatial resolution at the edge of FOV, Depth-Of-Interaction (DOI) PET has been investigated and several methods for DOI positioning were proposed. In this paper, a DOI-PET detector module using two 8x4 array avalanche photodiodes (APDs) (Hamamatsu, S8550) and a 2 cm long LYSO scintillation crystal was proposed and its DOI characteristics were investigated experimentally. In order to measure DOI positions, signals from two APDs were compared. Energy resolution was obtained from the sum of two APDs' signals and DOI positioning error was calculated. Finally, an optimum DOI step size in a 2 cm long LYSO were suggested to help to design a DOI-PET

  2. Limitations of commonly used thick-element personal dosimeters

    International Nuclear Information System (INIS)

    Gupta, V.P.

    1983-01-01

    In the ANSI Standard N13.11, accepted in June 1982, radiation dose depths of 1.0 cm and 0.007 cm in tissue for protection dosimetry have been adopted for deep and shallow dose equivalent estimations respectively. This standard is presently used for a mandatory personnel dosimetry performance testing program in the United States. Estimation of shallow-dose equivalent using a two-element dosimeter is described under the guidelines of this standard and the dosimetry practices followed by most dosimeter processors. A mathematical formulation, correlating a dosimeter response and shallow-dose equivalent factors at different energies, is presented. Also, the performance of a two-element thermoluminescent dosimeter is examined and the shallow-dose equivalent response results, both for the beta particles and photons, are discussed

  3. A simple model of EG and G reverse reach-through APDs

    CERN Document Server

    Musienko, Y; Swain, J D

    2000-01-01

    A simple model of reverse reach-through APDs is described. APD parameters including the dependence of the electric field and gain on the bias voltage, dependence of gain on wavelength are calculated using the McIntyre approach and an assumed doping profile of the APD.

  4. A simple model of EG and G reverse reach-through APDs

    Energy Technology Data Exchange (ETDEWEB)

    Musienko, Y. E-mail: iouri.moussienko@cern.ch; Reucroft, S.; Swain, J

    2000-03-11

    A simple model of reverse reach-through APDs is described. APD parameters including the dependence of the electric field and gain on the bias voltage, dependence of gain on wavelength are calculated using the McIntyre approach and an assumed doping profile of the APD.

  5. Radon daughter dosimeter

    International Nuclear Information System (INIS)

    Durkin, J.

    1977-01-01

    This patent describes a portable radon daughter dosimeter unit used to measure radon gas alpha daughters in ambient air. These measurements can then be related to preselected preestablished standards contained in a remote central readout unit. The dosimeter unit is adapted to be worn by an operator in areas having alpha particle radiation such as in uranium mines. Within the dosimeter is a detector head housing having a filter head and a solid state surface barrier radiation detector; an air pump to get air to the detector head; a self contained portable power supply for the unit; and electronic circuitry to process detected charged electrons from the detector head to convert and count their pulses representatives of two alpha radon emitter daughters. These counted pulses are in binary form and are sent to a readout unit where a numerical readout displays the result in terms of working level-hours

  6. Radon daughter dosimeter

    International Nuclear Information System (INIS)

    Durkin, J.

    1977-01-01

    A portable radon daughter dosimeter unit used to measure Radon gas alpha daughters in ambient air is described. These measurements can then be related to preselected preestablished standards contained in a remote central readout unit. The dosimeter unit is adapted to be worn by an operator in areas having alpha particle radiation such as uranium mines. Within the dosimeter is a detector head housing having a filter head and a solid state surface barrier radiation detector; an air pump to get air to the detector head; a self contained portable power supply for the unit; and electronic circuitry to process detected charged electrons from the detector head to convert and count their pulses representatives of two alpha radon emitter daughters. These counted pulses are in binary form and are sent to a readout unit where a numerical readout diplays the result in terms of working level-hours

  7. Fundamentals of Polymer Gel Dosimeters

    Science.gov (United States)

    McAuley, Kim B.

    2006-12-01

    The recent literature on polymer gel dosimetry contains application papers and basic experimental studies involving polymethacrylic-acid-based and polyacrylamide-based gel dosimeters. The basic studies assess the relative merits of these two most commonly used dosimeters, and explore the effects of tetrakis hydroxymethyl phosphonium chloride (THPC) antioxidant on dosimeter performance. Polymer gel dosimeters that contain THPC or other oxygen scavengers are called normoxic dosimeters, because they can be prepared under normal atmospheric conditions, rather than in a glove box that excludes oxygen. In this review, an effort is made to explain some of the underlying chemical phenomena that affect dosimeter performance using THPC, and that lead to differences in behaviour between dosimeters made using the two types of monomer systems. Progress on the development of new more effective and less toxic dosimeters is also reported.

  8. Radiation dosimeter assembly

    International Nuclear Information System (INIS)

    Seidel, J.G.

    1982-01-01

    A technique is disclosed for securing a thermoluminescent radiation dosimeter, used for monitoring underground radon gas in uranium prospecting, to a cup-like support member made of heavy gauge aluminum foil. A metalized film, consisting of an aluminum layer and a high tensile strength plastic layer, covers an aperture in the support members for the dosimeter. The film is secured by a high temperature adhesive to the support member, and both are capable of withstanding an annealing temperature of up to 300 0 C

  9. Study of personnel monitoring programs

    International Nuclear Information System (INIS)

    Guerra, Aline B.; Lorenzini, Fabiane; Carlos, Janaina; Bernasiuk, Maria E.B.; Rizzatti, Mara R.; Fuentefria, Jose L.B.

    1996-01-01

    Surveillance of several health institutions who use ionizing radiation sources, as well as data from the state of Rio Grande do Sul (Brazil) are studied concerning the use of personnel dosimeters. The results show that several institutions do not provide them and those which provide do not know how to use them

  10. Study of a plastic detector as a neutron dosimeter

    International Nuclear Information System (INIS)

    Cuauhtecatl Hernandes, V.

    1982-01-01

    Studies were carried out through nuclear reactions (n, p); (n, heavy ion), and (n,α) of the dosimetric properties of CR 39 commercial brand polymers. A system was devised for calculating the number of neutron induced nuclear reactions and geometric absolute efficiency factors. Feasibility of the utilization of CR 39 in monitoring and in personnel dosimeters is also discussed. (author)

  11. Thermoluminescence dosimeter reader

    International Nuclear Information System (INIS)

    Robertson, M.E.A.; Marshall, J.; Brabants, J.A.P.; Davies, M.E.

    1975-01-01

    An electric circuit arrangement is described including a photomultiplier tube and a high voltage source therefor also includes a feedback loop from the output of the tube to the high voltage source, and loop providing automatic gain stabilization for the tube. The arrangement is used in a dosimeter reader to provide sensitivity correction for the reader each time the reader is to be used

  12. Detectors for proton counting. Si-APD and scintillation detectors

    International Nuclear Information System (INIS)

    Kishimoto, Shunji

    2008-01-01

    Increased intensity of synchrotron radiation requests users to prepare photon pulse detectors having higher counting rates. As detectors for photon counting, silicon-avalanche photodiode (Si-APD) and scintillation detectors were chosen for the fifth series of detectors. Principle of photon detection by pulse and need of amplification function of the detector were described. Structure and working principle, high counting rate measurement system, bunch of electrons vs. counting rate, application example of NMR time spectroscopy measurement and comments for users were described for the Si-APD detector. Structure of scintillator and photomultiplier tube, characteristics of scintillator and performance of detector were shown for the NaI detector. Future development of photon pulse detectors was discussed. (T. Tanaka)

  13. Characterization of irradiated APDs for picosecond time measurements

    Science.gov (United States)

    Centis Vignali, M.; Dalal, R.; Gallinaro, M.; Harrop, B.; Jain, G.; Lu, C.; McClish, M.; McDonald, K. T.; Moll, M.; Newcomer, F. M.; Ugobono, S. Otero; White, S.

    2018-01-01

    For their operation at the CERN High Luminosity Large Hadron Collider (HL-LHC), the ATLAS and CMS experiments are planning to implement dedicated systems to measure the time of arrival of minimum ionizing particles with an accuracy of about 30 ps. The timing detectors will be subjected to radiation levels corresponding up to a 1-MeV neutrons fluence (Φeq) of 1015 cm-2 for the goal integrated luminosity of HL-LHC of 3000 fb-1. In this paper, deep-diffused Avalanche Photo Diodes (APDs) produced by Radiation Monitoring Devices are examined as candidate timing detectors for HL-LHC applications. These APDs are operated at 1.8 kV, resulting in a gain of up to 500. The timing performance of the detectors is evaluated using a pulsed laser. The effects of radiation damage on current, signal amplitude, noise, and timing performance of the APDs are evaluated using detectors irradiated with neutrons up to Φeq = 1015 cm-2.

  14. Personnel dosimetry in fluoroscopy

    International Nuclear Information System (INIS)

    Baechler, S.; Gardon, M.; Bochud, F.; Sans-Merce, M.; Verdun, F.R.; Trueb, Ph.

    2006-01-01

    Physicians who frequently perform fluoroscopic examinations are exposed to high intensity radiation fields and should use protective equipment such as lead aprons, thyroid shields and lead glasses. Standard individual dosimeters are worn under the lead apron in order to measure a dose that is representative of effective dose. However, large parts of the body are not protected by the apron (e.g. arms, head). Given a protection factor for the apron of about 100, an important irradiation of a body part not under the apron could go undetected. A study was conducted to analyse this situation by measuring dose using two dosimeters, one over-apron and one under-apron, for radiologists performing frequent fluoroscopic examinations. Measurements made over six-month period show that, indeed, the use of a single under-apron dosimeter is inadequate for personnel monitoring. Large doses to the head and arms are going undetected by this technique. A method for weighting the doses measured by under- and over-apron dosimeters to obtain a value better representative of the effective dose will be proposed. (authors)

  15. PNNL Results from 2010 CALIBAN Criticality Accident Dosimeter Intercomparison Exercise

    International Nuclear Information System (INIS)

    Hill, Robin L.; Conrady, Matthew M.

    2011-01-01

    This document reports the results of the Hanford personnel nuclear accident dosimeter (PNAD) and fixed nuclear accident dosimeter (FNAD) during a criticality accident dosimeter intercomparison exercise at the CEA Valduc Center on September 20-23, 2010. Pacific Northwest National Laboratory (PNNL) participated in a criticality accident dosimeter intercomparison exercise at the Commissariat a Energie Atomique (CEA) Valduc Center near Dijon, France on September 20-23, 2010. The intercomparison exercise was funded by the U.S. Department of Energy, Nuclear Criticality Safety Program, with Lawrence Livermore National Laboratory as the lead Laboratory. PNNL was one of six invited DOE Laboratory participants. The other participating Laboratories were: Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Savannah River Site (SRS), the Y-12 National Security Complex at Oak Ridge, and Sandia National Laboratory (SNL). The goals of PNNL's participation in the intercomparison exercise were to test and validate the procedures and algorithm currently used for the Hanford personnel nuclear accident dosimeters (PNADs) on the metallic reactor, CALIBAN, to test exposures to PNADs from the side and from behind a phantom, and to test PNADs that were taken from a historical batch of Hanford PNADs that had varying degrees of degradation of the bare indium foil. Similar testing of the PNADs was done on the Valduc SILENE test reactor in 2009 (Hill and Conrady, 2010). The CALIBAN results are reported here.

  16. Evaluation of discrepancies between thermoluminescent dosimeter and direct-reading dosimeter results

    International Nuclear Information System (INIS)

    Shaw, K.R.

    1993-07-01

    Currently at Oak Ridge National Laboratory (ORNL), the responses of thermoluminescent dosimeters (TLDs) and direct-reading dosimeters (DRDs) are not officially compared or the discrepancies investigated. However, both may soon be required due to the new US Department of Energy (DOE) Radiological Control Manual. In the past, unofficial comparisons of the two dosimeters have led to discrepancies of up to 200%. This work was conducted to determine the reasons behind such discrepancies. For tests conducted with the TLDs, the reported dose was most often lower than the delivered dose, while DRDs most often responded higher than the delivered dose. Trends were identified in personnel DRD readings, and ft was concluded that more training and more control of the DRDs could improve their response. TLD responses have already begun to be improved; a new background subtraction method was implemented in April 1993, and a new dose algorithm is being considered. It was concluded that the DOE Radiological Control Manual requirements are reasonable for identifying discrepancies between dosimeter types, and more stringent administrative limits might even be considered

  17. Temperature dependence of APD-based PET scanners

    International Nuclear Information System (INIS)

    Keereman, Vincent; Van Holen, Roel; Vandenberghe, Stefaan; Vanhove, Christian

    2013-01-01

    Purpose: Solid state detectors such as avalanche photodiodes (APDs) are increasingly being used in PET detectors. One of the disadvantages of APDs is the strong decrease of their gain factor with increasing ambient temperature. The light yield of most scintillation crystals also decreases when ambient temperature is increased. Both effects lead to considerable temperature dependence of the performance of APD-based PET scanners. In this paper, the authors propose a model for this dependence and the performance of the LabPET8 APD-based small animal PET scanner is evaluated at different temperatures.Methods: The model proposes that the effect of increasing temperature on the energy histogram of an APD-based PET scanner is a compression of the histogram along the energy axis. The energy histogram of the LabPET system was acquired at 21 °C and 25 °C to verify the validity of this model. Using the proposed model, the effect of temperature on system sensitivity was simulated for different detector temperature coefficients and temperatures. Subsequently, the effect of short term and long term temperature changes on the peak sensitivity of the LabPET system was measured. The axial sensitivity profile was measured at 21 °C and 24 °C following the NEMA NU 4-2008 standard. System spatial resolution was also evaluated. Furthermore, scatter fraction, count losses and random coincidences were evaluated at different temperatures. Image quality was also investigated.Results: As predicted by the model, the photopeak energy at 25 °C is lower than at 21 °C with a shift of approximately 6% per °C. Simulations showed that this results in an approximately linear decrease of sensitivity when temperature is increased from 21 °C to 24 °C and energy thresholds are constant. Experimental evaluation of the peak sensitivity at different temperatures showed a strong linear correlation for short term (2.32 kcps/MBq/°C = 12%/°C, R = −0.95) and long term (1.92 kcps/MBq/°C = 10%/

  18. Performance evaluation of a colorimetric hydrazine dosimeter

    Science.gov (United States)

    Brenner, Karen P.; Rose-Pehrsson, Susan L.

    1994-06-01

    A dosimeter for real-time, colorimetric detection of hydrazine in air has been developed. The passive badge consists of a dosimeter card containing a vanillin solution coated on a thin paper substrate. The active patch consists of a thick cellulose substrate coated with a vanillin solution. When placed in a plastic sample holder attached to a personnel pump, up to 5 L/min can be drawn through the active badge substrate. Through a condensation reaction, vanillin reacts with hydrazine to form a colored product that absorbs in the visible region. The hydrazone formed in the reaction is yellow; its intensity is proportional to the dose. When exposed passively to hydrazine, the experimental detection limit is less than 20 ppb-hrs. Extrapolated results indicate a detection limit of less than 5 ppb-hrs for long sampling periods. Actively sampling of hydrazine vapors gives an experimental detection limit of less than 100 ppb-L at a sample rate of 5 L/min. Relative humidity effects on badge response were minor. High humidity enhanced the color development on the vanillin badge; while low humidity had no effect on badge response. Interference testing of the dosimeters revealed a tobacco smoke interference. Preliminary shelf life tests indicated no decrease in sensitivity to hydrazine when stored at room temperature for 6 months.

  19. Personnel radiation dose assessment using a novel dosimeter in the department of radiology and dentistry in a medical facility in Delta State, South-South Nigeria: Our experience in the last 4 years

    OpenAIRE

    Omojola, Akintayo Daniel; Akpochafor, Michael Onoride; Adeneye, Samuel Olaolu; Aniekop, Ukeme Pius; Anizor, Margaret Idongesit; Ekpo, Mary-Ann Etim; Madu, Chibuzor Bede

    2018-01-01

    Objectives. Large percentagesof X-ray facilities in Nigeria do not use radiation monitoring device; a fewpercentage that use them do not evaluate or carryout out assessment programs toascertain the detriment to occupationally exposed workers. This study was aimedat evaluating dose reports from 2013 to 2016 for personnel who operate  radiation facilities and those that workwithin radiation field during certain X-ray procedures/examinations in thedepartment of radiology and dentistry respective...

  20. X-rays individual dose assessment using TLD dosimeters

    International Nuclear Information System (INIS)

    Salas, Carlos

    2008-01-01

    This paper describes the methodology used in Embalse NPP for measuring individual X-ray dose in dentists and radiologists, who work in areas near the plant. Personnel is provided with TLD personal dosimeters for thoracic use, as well as TLD ring dosimeters. This individual X-ray dosimetry is fundamental in order to know the effective energy coming from the radiation field, since the dosimetry factors depend on it. On the other hand, the response of the TLD crystals also depends of the effective energy; this accentuates the problem when assessing the individual dose. The X-ray dosimeter must simultaneously determine the value of the effective energy and the corresponding dose value. The basic principle for determining effective energy is by using at least two different TLD materials covered by filters of different thickness. The TLD materials used have totally energy responses. Therefore, different readouts from each of the crystals are obtained. The ratio between both readouts provides a factor that depends of the effective energy but that is 'independent' from the exposure values irradiated to the dosimeter. The Personal TLD dosimeter currently in use is Bicron-Harshaw. It comprises a carrier model 8807. This carrier contains a card model 2211 which groups two TLD 200 crystals and two TLD 100 crystals. It has internal filters at each side of the TLD 200 crystals. The periodical calibration of these dosimeters consists in the irradiation of some dosimeters with different X-ray energy beams in the National Atomic Energy Commission (CNEA). This dosimeter was used, by the National Regulatory Authority (ARN) in several comparisons, always getting satisfactory results. (author)

  1. Stable Chemical Dosimeters for Partial Reconstruction of Nuclear Accident Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Dvornik, I.; Zec, U.; Baric, M.; Razem, D. [Ruder Boskovic Nuclear Institute, Zagreb, Yugoslavia (Croatia)

    1969-10-15

    The application of chemical dosimeters, tissue equivalent with respect to gamma rays and neutrons, is proposed for dosimetric topography of the space around nuclear devices in case of accidents. The dosimeters in the form of sealed glass ampoules have sufficient sensitivity and long-term stability and are evaluated or checked directly by conventional spectrophotometry. The sensitivity, expressed as yield per rad, is approximately equal for gamma rays and neutrons. The resolution in both cases is about one rad, and the range is up to several thousand rads. The precision of dosimetry is {+-} 1 rad or {+-} 2%, whichever is higher. In free space and unshielded the dosimeter measures the total rad-absorbed dose delivered by gamma rays and neutrons, i.e. the first collision gamma plus neutron dose. If used on- or in-phantom, especially if several dosimeters are disposed within and around the same phantom, it can give important data about the amount of the neutron component of the dose and about the effective mean energy of incident neutrons. The neutron component of the dose can be directly measured if the gamma dosimeter is used together with the chemical dosimeter. The experiments giving the change of optical density per rad and the radiation chemical yield with respect to the absorbed dose delivered by 14-MeV neutrons are described in detail. The possibility is also mentioned of applying the dosimeter as a very sensitive monitor for thermal neutrons, which is due to the chlorine content of 4.73% and activation to {sup 38}Cl. The opinion is expressed that this dosimeter deserves some attention as a part of future planning and development work on area and personnel accidental dosimetry systems. (author)

  2. CRRES dosimeter simulations

    International Nuclear Information System (INIS)

    Auchampaugh, G.; Cayton, T.

    1993-04-01

    Conflicting data have been obtained from electron instruments aboard CRRES (Combined Release and Radiation Effects Satellite). To gain insight and to help in the interpretation of the data, we have calculated electron- and proton-flux and dose response functions for the four domes of the CRRES dosimeters using the Los Alamos Monte Carlo radiation transport codes. The response functions were calculated for electron and proton energies representative of those present in the space radiation environment. We also calculated the response of the dosimeters to a model radiation environment for orbit 607, which occurred on April 1, 1991 and compared the results to the measured values. The electron and proton components of the radiation environment were calculated using the solar maximum versions of the AE8 and AP8 models, namely, AE8MAX and AP8MAX. To facilitate the second task, we wrote two FORTRAN programs (CRRESunderscoreSIMP for AP8MAX and CRRESunderscoreSIME for AE8MAX) to read in a standard CRRES data file and to produce a comparison file of the calculated and measured values for all four dosimeter domes.The FORTRAN code will be available to the Phillips Laboratory for their use in making comparisons to other orbital data

  3. New Neutron Dosimeter

    CERN Multimedia

    2001-01-01

    CERN has been operating an Individual Dosimetry Service for neutrons for about 35 years. The service was based on nuclear emulsions in the form of film packages which were developed and scanned in the Service. In 1999, the supplier of theses packages informed CERN that they will discontinue production of this material. TIS-RP decided to look for an external service provider for individual neutron dosimetry. After an extensive market survey and an invitation for tender, a supplier that met the stringent technical requirements set up by CERN's host states for personal dosimeters was identified. The new dosimeter is based on a track-etching technique. Neutrons have the capability of damaging plastic material. The microscopic damage centres are revealed by etching them in a strong acid. The resulting etch pits can be automatically counted and their density is proportional to dose equivalent from neutrons. On the technical side, the new dosimeter provides an improved independence of its response from energy and th...

  4. Radiation dosimeters for medical use

    International Nuclear Information System (INIS)

    Risticj, S. Goran

    2013-01-01

    The several personal radiation dosimeter types for medical use, which look like promising for this kind of application, as pMOS (RADFET) dosimeter, direct ion storage (DIS) dosimeters, thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimeters, are described, and their advantages and disadvantages are analyzed. The p-channel metal-oxide-semiconductor (pMOS) dosimetric transistors allow dose measurements in vivo in real time, and they are especially important for radiotherapy. Direct ion storage (DIS) dosimeters are a hybrid of ion chamber and floating gate MOSFETs (FGMOSFETs), show very high sensitivity. Radiative processes that happen during the exposure of crystal to radiation are classified as prompt luminescence or radioluminescence (RL). In the case of an emission during stimulation, this phenomenon is referred to thermoluminescence or optically stimulated luminescence depending on whether the stimulation source is heat or light. TL and OSL dosimeters are natural or synthetic materials, which the intensity of emitted light is proportional to the irradiation dose. (Author)

  5. Technical guidelines for personnel dosimetry calibrations

    International Nuclear Information System (INIS)

    Roberson, P.L.; Fox, R.A.; Hadley, R.T.; Holbrook, K.L.; Hooker, C.D.; McDonald, J.C.

    1983-01-01

    A base of technical information has been acquire and used to evaluate the calibration, design, and performance of selected personnel systems in use at Department of Energy (DOE) facilites. A technical document was prepared to guide DOE and DOE contractors in selecting and evaluating personnel dosimetry systems and calibration. A parallel effort was initiated to intercompare the adiological calibrations standards used to calibrate DOE personnel dosimeters

  6. Copper doped borate dosimeters revisited

    Energy Technology Data Exchange (ETDEWEB)

    Alajerami, Y.S.M. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Department of Medical Radiography, Al-Azhar University, Gaza Strip, Palestine (Country Unknown); Hashim, S., E-mail: suhairul@utm.my [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Oncology Treatment Centre, Sultan Ismail Hospital, 81100 Johor Bahru (Malaysia); Ghoshal, S.K. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Bradley, D.A. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Mhareb, M. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Saleh, M.A. [Department of Physics, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); National Atomic Energy Commission (NATEC), Sana' a (Yemen)

    2014-11-15

    We render a panoramic overview on copper (Cu) doped borate dosimeters. Preparing a dosimeter by mixing specific materials with precise weights and methods is a never-ending quest. The recommended composition is highly decisive for accurate estimation of the absorbed dose, prediction of the biological outcome, determination of the treatment dose for radiation therapy and facilitation of personal monitoring. Based on these principles, the proposed dosimeter must cover a series of dosimetric properties to realize the exact results and assessment. The doped borate dosimeters indeed demonstrate attractive thermoluminescence (TL) features. Several dedicated efforts are attempted to improve the luminescence properties by doping various transition metals or rare-earth elements. The Cu ion being one of the preferred activators shows excellent TL properties as revealed via detail comparison with other dosimeters. Two oxide states of Cu (Cu{sup +} and Cu{sup ++}) with reasonable atomic number allow easy interaction with boron network. Interestingly, the intrinsic luminescent centers of borate lattice are in cross linked with that of Cu{sup +} ions. Thus, the activation of borate dosimeter with Cu ions for the enhancement of the TL sensitivity is recognized. These dosimeters reveal similar glow curves as the standard TLD-100 (LiF:Mg,Ti) one irrespective of the use of modifiers and synthesis techniques. They display high sensitivity, low fading, dose response linearity over wide range and practical minimum detectable dose. Furthermore, the effective atomic number being the most beneficial aspect (equivalent to that of human tissue) of borate dosimeters do not show any change due to Cu ion activations. The past development, major challenges, excitement, applications, recent progress and the future promises of Cu doped borate TL dosimeters are highlighted. - Highlights: • The manuscript gives a panoramic overview on copper doped borate dosimeters. • Cu ions activated

  7. Copper doped borate dosimeters revisited

    International Nuclear Information System (INIS)

    Alajerami, Y.S.M.; Hashim, S.; Ghoshal, S.K.; Bradley, D.A.; Mhareb, M.; Saleh, M.A.

    2014-01-01

    We render a panoramic overview on copper (Cu) doped borate dosimeters. Preparing a dosimeter by mixing specific materials with precise weights and methods is a never-ending quest. The recommended composition is highly decisive for accurate estimation of the absorbed dose, prediction of the biological outcome, determination of the treatment dose for radiation therapy and facilitation of personal monitoring. Based on these principles, the proposed dosimeter must cover a series of dosimetric properties to realize the exact results and assessment. The doped borate dosimeters indeed demonstrate attractive thermoluminescence (TL) features. Several dedicated efforts are attempted to improve the luminescence properties by doping various transition metals or rare-earth elements. The Cu ion being one of the preferred activators shows excellent TL properties as revealed via detail comparison with other dosimeters. Two oxide states of Cu (Cu + and Cu ++ ) with reasonable atomic number allow easy interaction with boron network. Interestingly, the intrinsic luminescent centers of borate lattice are in cross linked with that of Cu + ions. Thus, the activation of borate dosimeter with Cu ions for the enhancement of the TL sensitivity is recognized. These dosimeters reveal similar glow curves as the standard TLD-100 (LiF:Mg,Ti) one irrespective of the use of modifiers and synthesis techniques. They display high sensitivity, low fading, dose response linearity over wide range and practical minimum detectable dose. Furthermore, the effective atomic number being the most beneficial aspect (equivalent to that of human tissue) of borate dosimeters do not show any change due to Cu ion activations. The past development, major challenges, excitement, applications, recent progress and the future promises of Cu doped borate TL dosimeters are highlighted. - Highlights: • The manuscript gives a panoramic overview on copper doped borate dosimeters. • Cu ions activated technique in borate

  8. Evaluation of the neutron dose received by personnel at the LLNL

    International Nuclear Information System (INIS)

    Hankins, D.E.

    1982-01-01

    This report was prepared to document the techniques being used to evaluate the neutron exposures received by personnel at the LLNL. Two types of evaluations are discussed covering the use of the routine personnel dosimeter and of the albedo neutron dosimeter. Included in the report are field survey results which were used to determine the calibration factors being applied to the dosimeter readings. Calibration procedures are discussed and recommendations are made on calibration and evaluation procedures

  9. Characteristics of radiophotoluminescent glass dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Masashi; Shiraishi, Akemi; Murakami, Hiroyuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-07-01

    In Japan Atomic Energy Research Institute, a film badge is recently replaced by a new type radiophotoluminescent (RPL) glass dosimeter for external personal monitoring. Some fundamental characteristics of this dosimeter, such as dose dependence linearity, energy dependence, angular dependence, dose evaluation accuracy at mixed irradiation conditions, fading, etc., were examined at the Facility of Radiation Standard (FRS), JAERI. The results have proved that the RPL glass dosimeter has sufficient characteristics for practical use as a personal dosimeter for all of the items examined. (author)

  10. A G-APD based Camera for Imaging Atmospheric Cherenkov Telescopes

    International Nuclear Information System (INIS)

    Anderhub, H.; Backes, M.; Biland, A.; Boller, A.; Braun, I.; Bretz, T.; Commichau, S.; Commichau, V.; Dorner, D.; Gendotti, A.; Grimm, O.; Gunten, H. von; Hildebrand, D.; Horisberger, U.; Koehne, J.-H.; Kraehenbuehl, T.; Kranich, D.; Lorenz, E.; Lustermann, W.; Mannheim, K.

    2011-01-01

    Imaging Atmospheric Cherenkov Telescopes (IACT) for Gamma-ray astronomy are presently using photomultiplier tubes as photo sensors. Geiger-mode avalanche photodiodes (G-APD) promise an improvement in sensitivity and, important for this application, ease of construction, operation and ruggedness. G-APDs have proven many of their features in the laboratory, but a qualified assessment of their performance in an IACT camera is best undertaken with a prototype. This paper describes the design and construction of a full-scale camera based on G-APDs realized within the FACT project (First G-APD Cherenkov Telescope).

  11. The New APD Based Readout for the Crystal Barrel Calorimeter

    International Nuclear Information System (INIS)

    Urban, M; Honisch, Ch; Steinacher, M

    2015-01-01

    The CBELSA/TAPS experiment at ELSA measures double polarization observables in meson photoproduction off protons and neutrons. To be able to measure purely neutral reactions off polarized neutrons with high efficiency, the main calorimeter has to be integrated into the first level trigger. This requires to exchange the existing PIN photo diode by a new avalanche photo diode (APD) readout. The newly developed readout electronics will provide an energy resolution compatible to the previous set-up and a fast trigger signal down to 10 MeV energy deposit per crystal. After the successful final tests with a 3x3 CsI crystal matrix in Bonn at ELSA and in Mainz at MAMI all front-end electronics were produced in fall 2013. Automated test routines for the front-end electronics were developed and the characterization measurements of all APDs were successfully accomplished in Bonn. The project is supported by the Deutsche Forschungsgemeinschaft (SFB/TR16) and Schweizerischer Nationalfonds

  12. Development and underground testing of the α dosimeter: a solid state electronic personal radiation dosimeter for uranium miners

    International Nuclear Information System (INIS)

    Parkinson, R.N.; Roze, V.; Shepherd, R.

    1981-01-01

    The αDOSIMETER is a complete, integrated system designed to monitor the immediate worksite of underground miners where the disintegration for radon daughters is a risk to the health of mining personnel. The dosimeter weighing little more than one pound is worn by each miner throughout the entire shift and is powered by the miner's cap lamp battery. After this integration period, the unit is connected to a reading network whereupon the day's data is dumped, calculated and stored. Beginning in July 1980, prototype units were subjected to vigorous underground testing in uranium mines in Canada and the United States and in tin mines in Cornwall, UK. The testing results are summarized and proposals advanced for a typical mine monitoring system utilizing the αDOSIMETER

  13. A new radiochromic dosimeter film

    Science.gov (United States)

    Sidney, L. N.; Lynch, D. C.; Willet, P. S.

    By employing acid-sensitive leuco dyes in a chlorine-containing polymer matrix, a new radiochromic dosimeter film has been developed for gamma, electron beam, and ultraviolet radiation. These dosimeter films undergo a color change from colorless to royal blue, red fuchsia, or black, depending on dye selection, and have been characterized using a visible spectrophotometer over an absorbed dose range of 1 to 100 kGy. The primary features of the film are improved color stability before and after irradiation, whether stored in the dark or under artificial lights, and improved moisture resistance. The effects of absorbed dose, dose rate, and storage conditions on dosimeter performance are discussed. The dosimeter material may be produced as a free film or coated onto a transparent substrate and optionally backed with adhesive. Potential applications for these materials include gamma sterilization indicator films for food and medical products, electron beam dosimeters, and in-line radiation monitors for electron beam and ultraviolet processing.

  14. The neutron response of a 7 LiF thermoluminescent dosimeter incorporated in the UKAEA criticality dosimeter

    International Nuclear Information System (INIS)

    Eid, A.M.; Delafield, H.J.

    1976-04-01

    There are practical advantages in incorporating a 7 LiF thermoluminescent dosimeter (TLD) for the measurement of γ-ray dose, into the personnel criticality dosimeter. This paper investigated the corrections necessary for the inherent direct response of the TLD neutrons, and its enhanced indirect response from prompt γ-rays resulting from neutron interactions with the metallic foils contained in the criticality dosimeter. The response of the TLD to fast fission neutrons was measured to be 0.02 γ rad/n rad. The indirect response of the TLD to thermal neutrons was measured to be 4.8 x 10 -10 rad n -1 cm 2 for dosimeters exposed in free air, and 7 x 10 -10 rad n -1 cm 2 for dosimeters worn on the body respectively. Application of these correction factors to TLD measurements made at International Dosimetry Intercomparisons (sponsored by the I.A.E.A.) gave improved agreement with the values given by other participants. (author)

  15. Thermoluminescence and phosphate glass dosimeter systems in the low dose range

    International Nuclear Information System (INIS)

    Piesch, E.; Burgkhardt, B.

    1978-06-01

    This report describes a standard test program for TLD and RPL systems worked out by the Working Party on 'Dose Measurement of External Radiation' by the Fachverband fuer Strahlenschutz e.V. to demonstrate the performance of dosimeter systems to be employed in environmental monitoring and in personnel dosimetry. The results of an intercomparison study are outlined in which 17 laboratories from the German speaking countries participated with 43 dosimeter systems. (orig.) [de

  16. A systematic approach to personnel neutron monitoring

    International Nuclear Information System (INIS)

    Griffith, R.V.; Hankins, D.E.

    1980-01-01

    In selection, calibration and interpretation of personnel neutron dosimeters used in radiation protection, adequate attention is often not given to matching the characteristics of the dosimeter with the quality of the neutron field. A particular concern is the use of albedo detectors which have little energy response similarity to the neutron dose equivalent conversion curve. At the Lawrence Livermore Laboratory we have developed a system for dosimeter calibration and neutron field characterization using Bonner spheres and remmeters. Rapid surveys of the work area with detectors in 3-in and 9-in polyethylene spheres establish a qualitative estimate of spectral variation found in the facility. We also use this data to determine the appropriate albedo dosimeter calibration factors. At several locations representing the spectral range, multisphere spectra measure-ments are made and the spectrum weighted dose equivalent rates calculated. These rates are compared with survey instrument results to establish correction factors for the relative over- or under-response expected from these instruments, particularly in highly moderated neutron fields where remmeters overrespond. We also use the spectral information to determine the appropriateness of dosimeters considered for future use. This technique has been applied at power reactors to provide information valuable to selection of proper personnel dosimeters. We find that the spectral range is sufficiently narrow that albedo detectors can be used with confidence. On the other hand, most of the dose occurs at energies below the effective threshold NTA film. (author)

  17. Procedure for the delivering of personal short-term visitor dosimeters

    CERN Document Server

    2016-01-01

    Update of the administrative procedure for delivering a personal short-term visitor dosimeter to associated members of CERN’s personnel.   Associated members of the CERN personnel may request a short term visitor dosimeter if working only in Supervised Radiation Areas and for a period of less than two months in a calendar year. Such a dosimeter is delivered without the need to provide the usual regular documents: radiation passport, certificate from the home institute or medical certificate. Periodic verification will ensure that holders of these personal dosimeters do not exceed the maximum allowed personal dose for this type of dosimeter, which is the same as the limit for members of the public at 1 mSv per year. From now on, the two-month period can be spread over a calendar year, offering greater flexibility to users coming to CERN for multiple short periods. Please return unused dosimeters Persons leaving CERN for a period of more than one month should return their dosimeter to the D...

  18. A prospective, randomized multicenter study comparing APD and CAPD treatment

    DEFF Research Database (Denmark)

    Bro, S; Bjorner, J B; Tofte-Jensen, P

    2000-01-01

    , dialysis-related complications, dialysis-related expenses. RESULTS: The quality-of-life studies showed that significantly more time for work, family, and social activities was available to patients on APD compared to those on CAPD (p ...) treatment with respect to quality of life and clinical outcomes in relation to therapy costs. DESIGN: A prospective, randomized multicenter study. SETTING: Three Danish CAPD units. PATIENTS: Thirty-four adequately dialyzed patients with high or high-average peritoneal transport characteristics were included...... were assessed at baseline and after 6 months by the self-administered short-form SF-36 generic health survey questionnaire supplemented with disease- and treatment-specific questions. Therapy costs were compared by evaluating dialysis-related expenses. MAIN OUTCOME MEASURES: Quality-of-life parameters...

  19. APD Response Time Measurements for Future TOF-E Systems

    Science.gov (United States)

    Starkey, M. J.; Ogasawara, K.; Dayeh, M. A.; Desai, M. I.

    2017-12-01

    In space physics, the ability to detect ions is crucial to understanding plasma distributions in the solar wind. This usually typically requires the determination of the particle's mass, charge, and total energy. Current ion detection schemes are implemented in three sequential parts; an electrostatic analyzer for energy per charge (E/Q) measurements, a time-of-flight (TOF) for mass per charge (M/Q) measurements, and a solid-state detector (SSD) for total energy (E) measurements. Recent work has suggested the use of avalanche photodiode detectors (APD) for a simultaneous TOF and total energy (TOF-E) measurement system, which would replace traditional SSDs, simplify design, and reduce costs. Although TOF based ion spectrometry typically requires timing resolution of systems.

  20. Direct reading dosimeter

    International Nuclear Information System (INIS)

    Thomson, I.

    1985-01-01

    This invention is a direct reading dosimeter which is light, small enough to be worn on a person, and measures both dose rates and total dose. It is based on a semiconductor sensor. The gate threshold voltage change rather than absolute value is measured and displayed as a direct reading of the dose rate. This is effected by continuously switching the gate of an MOS transistor from positive to negative bias. The output can directly drive a digital readout or trigger an audible alarm. The sensor device can be a MOSFET, bipolar transistor, or MOSFET capacitor which has its electrical characteristics change due to the trapped charge in the insulating layer of the device

  1. Colorimetric gas dosimeter

    International Nuclear Information System (INIS)

    McConnaughey, P.W.; McKee, E.S.

    1984-01-01

    A gas dosimeter comprises a stack of porous sheets, impregnated with a reagent that changes color on contact with the gas to be determined, contained in a housing which has an opening to expose one end of the stack to the atmosphere to be tested. The gas to be determined penetrates by diffusion the layers of porous sheets, causing the sheets in the stack to change color sequentially from the end of the stack exposed to the atmosphere. The degree of penetration through the layers of porous sheets is a function of dosage exposure. The housing may be transparent with each superposed sheet in the stack being larger than the adjacent underlying sheet, so that each sheet is visible through the housing endwall

  2. The intelligence of dosimeter for ionization radiation

    International Nuclear Information System (INIS)

    He Jinglun

    1992-01-01

    The connection of dosimeter with microcomputer system is described, which has the functions of sampling, data handling, display and printing dose values in legal units of measurement. The accuracy and speed of measurement for dosimeters are also raised, thereby the dosimeters are made to have intelligence and the application range of dosimeter is enlarged

  3. Quo vadis, personnel monitoring

    International Nuclear Information System (INIS)

    Becker, K.

    1975-01-01

    With the increasing use of nuclear power and radiation sources, the selection of optimum systems for personnel monitoring is becoming a matter of worldwide concern. The present status of personnel dosimetry, sometimes characterized by unstable and inaccurate detectors and oversimplified interpretation of the results, leaves much to be desired. In particular, photographic film, although having certain advantages with regard to economics and information content, undergoes rapid changes in warm and humid climates. Careful sealing reduces, but does not prevent, these problems. The replacement of film by solid-state dosimeters, primarily thermoluminescence dosimeters, is in progress or being considered by an increasing number of institutions and requires a number of decisions concerning the choice of the optimum detector(s), badge design, and evaluation system; organizational matters, such as the desirability of automation and computerized bookkeeping; etc. The change also implies the potential use of such advanced concepts as different detectors and monitoring periods for the large number of low-risk persons and the small number of high-risk radiation workers. (auth)

  4. Silver nitrate based gel dosimeter

    International Nuclear Information System (INIS)

    Titus, D; Samuel, E J J; Srinivasan, K; Roopan, S M; Madhu, C S

    2017-01-01

    A new radiochromic gel dosimeter based on silver nitrate and a normoxic gel dosimeter was investigated using UV-Visible spectrophotometry in the clinical dose range. Gamma radiation induced the synthesis of silver nanoparticles in the gel and is confirmed from the UV-Visible spectrum which shows an absorbance peak at around 450 nm. The dose response function of the dosimeter is found to be linear upto12Gy. In addition, the gel samples were found to be stable which were kept under refrigeration. (paper)

  5. Evaluation of personal integrating dosimeters

    International Nuclear Information System (INIS)

    Correa, C.A.; Bisauta, Mauricio A.

    2007-01-01

    The objective of this work is to analyze the different types of dosimeters present in the international market that are used to provide personal dose monitoring, specifically for external gamma and beta radiation, Hp(10) and Hp (0,07), as well as to add comments of advances in the field of passive and operative dosimetry, and the changes that are being produced in the regulating policy in other countries regarding the use of this devices. The technical specification of each dosimeter has been extracted of different catalogues of products. To conclude, the importance has been stressed in a proper selection of dosimeters with its advantages and disadvantages before its use. (author) [es

  6. Heater design for reading radiation dosimeters

    International Nuclear Information System (INIS)

    Seidel, J.G.; Felice, P.E.

    1982-01-01

    The nichrome heating element of a conventional dosimeter reading apparatus has been redesigned to include a flat-bottomed depression big enough to hold a thermoluminescent dosimeter. A thin glass plate is positioned in the recess on top of the dosimeter to retain it in the recess during the heating and reading process. This technique of securing the dosimeter in contact with the heating element avoids physical scratching or damage to the dosimeter

  7. Citizen's dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Klemic, Gladys [Naperville, IL; Bailey, Paul [Chicago, IL; Breheny, Cecilia [Yonkers, NY

    2008-09-02

    The present invention relates to a citizen's dosimeter. More specifically, the invention relates to a small, portable, personal dosimetry device designed to be used in the wake of a event involving a Radiological Dispersal Device (RDD), Improvised Nuclear Device (IND), or other event resulting in the contamination of large area with radioactive material or where on site personal dosimetry is required. The card sized dosimeter generally comprises: a lower card layer, the lower card body having an inner and outer side; a upper card layer, the layer card having an inner and outer side; an optically stimulated luminescent material (OSLM), wherein the OSLM is sandwiched between the inner side of the lower card layer and the inner side of the upper card layer during dosimeter radiation recording, a shutter means for exposing at least one side of the OSLM for dosimeter readout; and an energy compensation filter attached to the outer sides of the lower and upper card layers.

  8. An Emergency Dosimeter for Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Braun, J; Nilsson, R

    1960-05-15

    A neutron dosimeter suitable for single emergency exposures is described. The dosimeter is furnished with detectors for thermal, epi-thermal and fast neutrons. This means that three of the constants by which the spectrum of the incident neutron flux is approximated, can be determined. The dose calculated from these approximated spectra is compared to the dose from spectra obtained in different standard spectra of types which may be expected in a radiation accident.

  9. Review of Fricke gel dosimeters

    International Nuclear Information System (INIS)

    Schreiner, L J

    2004-01-01

    The innovation of adding a gel matrix to the traditional Fricke dosimeter to stabilize geometric information established the field of gel dosimetry for radiation therapy. A discussion of Fricke gels provides an overview of the issues that determine the dose response of all gel dosimeters in general. In this paper we review some of the features of Fricke systems to illustrate these issues and, in addition, to motivate renewed clinical interest in Fricke gels

  10. Digital neutron dosimeter

    International Nuclear Information System (INIS)

    Ramondetta, P.W.; Groeber, E.O.Jr.

    1978-01-01

    Design features for a portable battery-operated neutron dosimeter are described. The system employs a 50-mil PIN detector diode, whose forward voltage increases with exposure to fast neutrons. Because this change is permanent and cumulative, the system is able to integrate small doses (from 0 to 1000 rad) over long periods of time. The system is temperature compensated over its operating range of -40 C to +52C. Display accuracies of +-20 rad for readings below 100 rad and +-20% for readings above 100 rad are maintained throughout the range. Temperature correction is performed digitally after an initial analog-to-digital conversion of both the forward diode voltage and the ambient temperature. System flexibility is promoted with the use of a replaceable ROM for the final voltage-to-dose conversion table. This digital approach to temperature compensation, combined with the extensive use of CMOS circuitry, suggests the use of custom large-scale integration as a means of further reducing system weight and size. This possibility, as well as others, is discussed as a means of reducing system size. Test and evaluation results are also included. (author)

  11. The Calvet calorimetric dosimeter

    International Nuclear Information System (INIS)

    Puig, J.R.; Romano, F.

    1965-01-01

    This report describes a dosimeter based on the conduction calorimetry principle, and designed to operate in swimming-pool type nuclear reactors. The properties of the apparatus are as follows: 1 - the measurement is independent of the specific heat of the calorimetric elements; 2 - each calorimetric element is fitted with an electrical calibration; 3 - the apparatus is made up of two independent calorimetric elements; 4 - the nature of the calorimetric elements makes it possible to analyse the radiation received; 5 - the measurable intensities of the absorbed radiation vary from 4 to 4000 M/rads per hour; 6 - the sensitive part of the apparatus is fitted inside a cylinder 5 cm high and 2 cm in diameter. One pre-production unit made up of graphite and beryllium cores has been tried out in the reactor Siloe with radiation intensities of about 1 to 2 watts per gram. It absorbed an accumulated dose of 1.2*1O 12 rads without any weaknesses appearing. (authors) [fr

  12. Study on the angular dependence of personal exposure dosimeter - Focus on thermoluminescent dosimeter and photoluminescent dosimeter

    International Nuclear Information System (INIS)

    Dong, Kyung-Rae; Kweon, Dae Cheol; Chung, Woon-Kwan; Goo, Eun-Hoe; Dieter, Kevin; Choe, Chong-Hwan

    2011-01-01

    Radiation management departments place more emphasis on the accuracy of measurements than on the increase in the average dose and personal exposure dose from the use of radiation equipment and radioactive isotopes. Although current measurements are taken using devices, such as film badge dosimeters, pocket dosimeters and thermoluminescent dosimeters (TLDs), this study compared the angular dependence between the widely used TLDs and photoluminescent dosimeter (PLDs) in order to present primary data and evaluate the utility of PLD as a new dosimeter device. For X-ray fluoroscopy, a whole body phantom was placed on a table with a setting for the G-I technical factors fixed at a range of approximately 40 cm with a range of ±90 o at an interval scale of 15 o from the center location of an average radiological worker for PLDs (GD-450) and TLDs (Carot). This process was repeated 10 times, and at each time, the cumulative dosage was interpreted from 130 dosimeters using TLDs (UD-710R, Panasonic) and PLDs (FGD-650). The TLD and PLD showed a 52% and 23% decrease in the depth dosage from 0 o to -90 o , respectively. Therefore, PLDs have a lower angular dependence than TLDs.

  13. Personnel radiation monitoring by thermoluminescence dosimetry (2000-2001)

    International Nuclear Information System (INIS)

    Mi-Cho-Cho, Daw; Hla-Hla-Win, Daw; Thin-Thin-Kraing

    2001-01-01

    Thermoluminescence dosimetry service was introduced in 1991. Personnel who exposed directly or indirectly to radiation is monitored by thermoluminescent dosimeter. TL materials used for thermoluminescent dosimeter are in the form of thin disc. Personnel whole-body and extremity doses are measured by thermoluminescence dosimetry. The Harshaw Model 4500 TLD reader and Vinten 654E TLD reader are used for TLD evaluation. At present about 600 radiation workers are provided with TLD for routine monitoring. It was found that most personnel had received within permissible dose recommended by the International Commission on Radiological Protection (ICRP). (author)

  14. Design and development of a PMOSFET gamma ray dosimeter

    International Nuclear Information System (INIS)

    Khanna, V.K.; Kumar, A.; Gupta, R.P.; Pandya, A.; Roy, Rajesh

    2005-01-01

    A P-channel MOSFET chip has been designed for detection of gamma radiations. The chip consists of three MOSFETs of different geometrical parameters for achieving sensitivity to low and high dose ranges. One of the MOSFET structures has a closed geometry to reduce the leakage current. The developed dosimeter being a MOSFET, its IC (Integrated Circuit)-compatibility helps in easy interfacing with readout circuitry. The dosimeter fabrication process is based on metal-gate MOSFET technology with thick gate oxide to increase the effective number of electron-hole pairs generated by the gamma rays impinging on the device. The process for the chip realization has been designed and simulated to achieve the required impurity diffusion profile. The chip has been fabricated using the above process and electrically characterized. The device has been exposed to gamma ray source and its characteristics measured. The change in threshold voltage of the MOSFET after exposure has been used to calculate the sensitivity of the device. The developed dosimeter has potential applications in personnel dosimetry and cancer treatment. This paper describes the basic detection mechanism of the MOSFET, the design approach, and fabrication process of the MOSFET dosimeter. (author)

  15. Electronic dosimeter characteristics and new developments

    International Nuclear Information System (INIS)

    Thompson, I.M.G.

    1999-01-01

    Electronic dosimeters are very much more versatile than existing passive dosimeters such as TLDs and film badges which have previously been the only type of dosimeters approved by national authorities for the legal measurement of doses to occupationally exposed workers. Requirements for the specifications and testing of electronic dosimeters are given in the standards produced by the International Electrotechnical Commission Working Group IEC SC45B/B8. A description is given of these standards and the use of electronic dosimeters as legal dosimeters is discussed. (author)

  16. Multiple benefits of personal FM system use by children with auditory processing disorder (APD).

    Science.gov (United States)

    Johnston, Kristin N; John, Andrew B; Kreisman, Nicole V; Hall, James W; Crandell, Carl C

    2009-01-01

    Children with auditory processing disorders (APD) were fitted with Phonak EduLink FM devices for home and classroom use. Baseline measures of the children with APD, prior to FM use, documented significantly lower speech-perception scores, evidence of decreased academic performance, and psychosocial problems in comparison to an age- and gender-matched control group. Repeated measures during the school year demonstrated speech-perception improvement in noisy classroom environments as well as significant academic and psychosocial benefits. Compared with the control group, the children with APD showed greater speech-perception advantage with FM technology. Notably, after prolonged FM use, even unaided (no FM device) speech-perception performance was improved in the children with APD, suggesting the possibility of fundamentally enhanced auditory system function.

  17. An advanced APD-based spectroscopic radiation monitor. Final Technical Report

    International Nuclear Information System (INIS)

    Mitchell Woodring, PhD; James Christian, PhD

    2007-01-01

    A highly sensitized radiation imager is under development through DOE SBIR contract DE-FG02-99ER 82866. This imager will be extraordinarily useful to the DOE in its decontamination and decommissioning activities. The basis for this advanced, state-of-the-art radiation imager is a new type of photon detector, an avalanche photodiode (APD). Only recently has APD technology advanced to the point where it is useful for applications like the radiation imager. To date, the major drawback in the use of avalanche photodiodes was the inability to use many of them in a single application because of the need for many channels of readout, complicated device holders, and dead space between detectors. RMD has solved this dilemma through the development of compact arrays of APDs. Additionally, the fabrication technique has been refined to the point were the bulk production of large quantities of arrays is now feasible. These new APD arrays have excellent application flexibility. The capability to tailor the detector properties; such as size, sensitivity, pixellation, and pitch make APD arrays excellent candidates for a variety of photosensing schemes previously dominated by photomultiplier tubes (PMT). In fact, at RMD it is currently possible to make APD arrays with 2-mm 2 detectors (pixels) in monolithic square arrays 14 pixels on a side (196 detectors). As proposed in Phase II work, paneling 9 of these arrays (as the basis of a highly sensitive radiation imager) would make a photodetector that was 100 cm 2 in sensitive area. This results in approximately 1800 individual detectors that require data sampling and control. This is an enormous electronics load. To reduce the electronics complexity for the readout scheme of APD arrays (one of the major aspects of the proposed Phase II research) individual detectors (in the array) will be grouped together on common readout lines by rows and columns. This row-column-addressing scheme reduces the readout complexity from 1800 to 90 if 42

  18. Mexican gems as thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    Azorin N, J.

    1979-01-01

    The possibility of using naturally ocurring mexican gems as thermoluminescent dosimeters (TLD) was investigated. Twelve types of gems were irradiated with X and gamma rays in order to determinate their dosimetric properties. Three of these gems showed favorable thermoluminescent characteristics compared with commercial thermoluminescent dosimeters. The plots of their thermoluminescent response as a function of gamma dose are straight lines on full log paper in the dose range 10 -2 to 10 2 Gy. The energy dependence is very strong to low energies of the radiation. Their fading was found to be about 5%/yr. and they may be annealed as reused without loss in sensitivity. Therefore, these gems can be used as X and gamma radiation dosimeters. (author)

  19. CVD diamond detectors and dosimeters

    International Nuclear Information System (INIS)

    Manfredotti, C.; Fizzotti, F.; LoGiudice, A.; Paolini, C.; Oliviero, P.; Vittone, E.; Torino Univ., Torino

    2002-01-01

    Natural diamond, because of its well-known properties of tissue-equivalence, has recorded a wide spreading use in radiotherapy planning with electron linear accelerators. Artificial diamond dosimeters, as obtained by Chemical Vapour Deposition (CVD) could be capable to offer the same performances and they can be prepared in different volumes and shapes. The dosimeter sensitivity per unit volume may be easily proved to be better than standard ionization microchamber. We have prepared in our laboratory CVD diamond microchamber (diamond tips) in emispherical shape with an external diameter of 200 μm, which can be used both as X-ray beam profilometers and as microdosimeters for small field applications like stereotaxy and also for in vivo applications. These dosimeters, which are obtained on a wire substrate that could be either metallic or SiC or even graphite, display good performances also as ion or synchrotron X-rays detectors

  20. To the attention of all dosimeter users

    CERN Multimedia

    2005-01-01

    Many regular users of CERN personal dosimeters do not respect the safety regulations, which include a compulsory monthly read-out of the dosimeter. Therefore we would like to remind everybody that if the dosimeter is not read for a period of 3 months or more, we will ask for a return or replacement of the dosimeter, which has a value of CHF 350.-. We would like to emphasise that the dosimeter must be read even if you have not entered controlled areas. Staff members or CERN users who enter controlled areas only occasionally may exchange their regular dosimeter for a short term visitor dosimeter (VCT). This dosimeter has a limited validity period but without for a compulsory periodic read-out. For further information please contact dosimetry.service@cern.ch Thank you for your cooperation. Dosimetry Service Bldg. 24 E 011 http://cern.ch/rp-dosimetry

  1. To the attention of all dosimeter users

    CERN Multimedia

    Dosimetry Service

    2005-01-01

    Many regular users of CERN personal dosimeters do not respect the safety regulations, which include the compulsory monthly read-out of the dosimeter. Therefore we would like to remind everybody that if the dosimeter is not read for a period of 3 months or more, we will ask for a return or replacement of the dosimeter, which has a value of CHF 350.-. We would like to emphasise that the dosimeter must be read even if you have not entered controlled areas. Staff members or CERN users who enter controlled areas only occasionally may exchange their regular dosimeter for a short term visitor dosimeter (VCT). This dosimeter has a limited validity period but without for a compulsory periodic read-out. For further information please contact dosimetry.service@cern.ch Thank you for your cooperation. Dosimetry Service Bld 24 E 011 http://cern.ch/rp-dosimetry

  2. To the attention of all dosimeter users

    CERN Multimedia

    Dosimetry Service

    2006-01-01

    Many regular users of CERN personal dosimeters do not respect the safety regulations, which include the compulsory monthly read-out of the dosimeter. We would therefore like to remind everybody that if the dosimeter is not read for a period of 3 months or more, we will ask for a return or replacement of the dosimeter, which has a value of CHF 350,-. We would like to emphasise that the dosimeter must be read even if you have not entered controlled areas. Staff members or CERN users who enter controlled areas only occasionally may exchange their regular dosimeter for a short-term visitor dosimeter (VCT). This dosimeter has a limited validity period but does not require a periodic read-out. For further information please contact dosimetry.service@cern.ch Thank you for your cooperation. Dosimetry Service - Bldg. 24 E 011 - http://cern.ch/rp-dosimetry

  3. Neutron personnel dosimetry

    International Nuclear Information System (INIS)

    Griffith, R.V.

    1982-01-01

    The measurement of neutron exposures to personnel is an issue that has received increased attention in the last few years. It is important to consider key aspects of the whole dosimetry system when developing dose estimates. This begins with selection of proper dosimeters and survey instruments, and extends through the calibration methods. One must match the spectral response and sensitivity of the dosimeter to the spectral characteristics of the neutron fields. Threshold detectors that are insensitive to large fractions of neutrons in the lower energy portion of reactor spectra should be avoided. Use of two or more detectors with responses that complement each other will improve measurement quality. It is important to understand the spectral response of survey instruments, so that spectra which result in significant overresponse do not lead to overestimation of dose. Calibration sources that do not match operational field spectra can contribute to highly erroneous results. In those situations, in-field calibration techniques should be employed. Although some detection developments have been made in recent years, a lot can be done with existing technology until fully satisfactory, long term solutions are obtained

  4. SU-E-I-57: Estimating the Occupational Eye Lens Dose in Interventional Radiology Using Active Personal Dosimeters Worn On the Chest

    Energy Technology Data Exchange (ETDEWEB)

    Omar, A; Marteinsdottir, M; Kadesjo, N; Fransson, A [Dept. of Medical Physics, Karolinska University Hospital, Stockholm (Sweden)

    2015-06-15

    Purpose: To provide a general formalism for determination of occupational eye lens dose based on the response of an active personal dosimeter (APD) worn at chest level above the radiation protection apron. Methods: The formalism consists of three factors: (1) APD conversion factor converting the reading at chest level (APDchest) to the corresponding personal dose equivalent at eye level, (2) Dose conversion factor transferring the measured dose quantity, Hp(10), into a dose quantity relevant for the eye lens dose, (3) Correction factor accounting for differences in exposure of the eye(s) compared to the exposure at chest level (e.g., due to protective lead glasses).The different factors were investigated and evaluated based on phantom and clinical measurements performed in an x-ray angiography suite for interventional cardiology. Results: The eye lens dose can be conservatively estimated by assigning an appropriate numerical value to each factor entering the formalism that in most circumstances overestimates the dose. Doing so, the eye lens dose to the primary operator and assisting staff was estimated in this work as D-eye,primary = 2.0 APDchest and D-eye,assisting = 1.0 APDchest, respectively.The annual eye lens dose to three nurses and one cardiologist was estimated to be 2, 2, 2, and 13 mSv (Hp(0.07)), respectively, using a TLD dosimeter worn at eye level. In comparison, using the formalism and APDchest measurements, the respective doses were 2, 2, 2, and 16 mSv (Hp(3)). Conclusion: The formalism outlined in this work can be used to estimate the occupational eye lens dose from the response of an APD worn on the chest. The formalism is general and could be applied also to other types of dosimeters. However, the numerical value of the different factors may differ from those obtained with the APD’s used in this work due to differences in dosimeter properties.

  5. SU-E-I-57: Estimating the Occupational Eye Lens Dose in Interventional Radiology Using Active Personal Dosimeters Worn On the Chest

    International Nuclear Information System (INIS)

    Omar, A; Marteinsdottir, M; Kadesjo, N; Fransson, A

    2015-01-01

    Purpose: To provide a general formalism for determination of occupational eye lens dose based on the response of an active personal dosimeter (APD) worn at chest level above the radiation protection apron. Methods: The formalism consists of three factors: (1) APD conversion factor converting the reading at chest level (APDchest) to the corresponding personal dose equivalent at eye level, (2) Dose conversion factor transferring the measured dose quantity, Hp(10), into a dose quantity relevant for the eye lens dose, (3) Correction factor accounting for differences in exposure of the eye(s) compared to the exposure at chest level (e.g., due to protective lead glasses).The different factors were investigated and evaluated based on phantom and clinical measurements performed in an x-ray angiography suite for interventional cardiology. Results: The eye lens dose can be conservatively estimated by assigning an appropriate numerical value to each factor entering the formalism that in most circumstances overestimates the dose. Doing so, the eye lens dose to the primary operator and assisting staff was estimated in this work as D-eye,primary = 2.0 APDchest and D-eye,assisting = 1.0 APDchest, respectively.The annual eye lens dose to three nurses and one cardiologist was estimated to be 2, 2, 2, and 13 mSv (Hp(0.07)), respectively, using a TLD dosimeter worn at eye level. In comparison, using the formalism and APDchest measurements, the respective doses were 2, 2, 2, and 16 mSv (Hp(3)). Conclusion: The formalism outlined in this work can be used to estimate the occupational eye lens dose from the response of an APD worn on the chest. The formalism is general and could be applied also to other types of dosimeters. However, the numerical value of the different factors may differ from those obtained with the APD’s used in this work due to differences in dosimeter properties

  6. Flame-sintered ceramic exoelectron dosimeter samples

    International Nuclear Information System (INIS)

    Petel, M.; Holzapfel, G.

    1979-01-01

    New techniques for the preparation of integrating solid state dosimeters, particularly exoelectron dosimeters, have been initiated. The procedure consists in melting the powdered dosimeter materials in a hot, fast gas stream and depositing the ceramic layer. The gas stream is generated either through a chemical flame or by an electrical arc plasma. Results will be reported on the system Al 2 O 3 /stainless steel as a first step to a usable exoelectron dosimeter

  7. Dosimeter charging and/or reading apparatus

    International Nuclear Information System (INIS)

    Fine, L.T.; Jackson, T.P.

    1980-01-01

    A device is disclosed for charging and/or reading a capacitor associated with an electrometer incorporated in a radiation dosimeter for the purpose of initializing or ''zeroing'', the dosimeter at the commencement of a radiation measurement cycle or reading it at any time thereafter. The dosimeter electrometer has a movable electrode the position of which is indicative of the charge remaining on the dosimeter capacitor and in turn the amount of radiation incident on the dosimeter since it was zeroed. The charging device also includes means for discharging, immediately upon conclusion of the dosimeter capacitor charging operation, stray capacitance inherent in the dosimeter by reason of its mechanical construction. The charge on the stray capacitance, if not discharged at the conclusion of the dosimeter capacitor charging operation, leaks off during the measurement cycle, introducing measurement errors. A light source and suitable switch means are provided for automatically illuminating the movable electrode of the dosimeter electrometer as an incident to charging the dosimeter capacitor to facilitate reading the initial, or ''zero'', position of the movable electrometer electrode after the dosimeter capacitor has been charged and the stray capacitance discharged. Also included is a manually actuatable switch means, which is operable independently of the aforementioned automatic switch means, to energize the lamp and facilitate reading of the dosimeter without charging

  8. Personnel neutron dosimetry at Department of Energy facilities

    International Nuclear Information System (INIS)

    Brackenbush, L.W.; Endres, G.W.R.; Selby, J.M.; Vallario, E.J.

    1980-08-01

    This study assesses the state of personnel neutron dosimetry at DOE facilities. A survey of the personnel dosimetry systems in use at major DOE facilities was conducted, a literature search was made to determine recent advances in neutron dosimetry, and several dosimetry experts were interviewed. It was concluded that personnel neutron dosimeters do not meet current needs and that serious problems exist now and will increase in the future if neutron quality factors are increased and/or dose limits are lowered

  9. Response of TLD-albedo and nuclear track dosimeters exposed to plutonium sources

    International Nuclear Information System (INIS)

    Brackenbush, L.W.; Baumgartner, W.V.; Fix, J.J.

    1991-12-01

    Neutron dosimetry has been extensively studied at Hanford since the mid-1940s. At the present time, Hanford contractors use thermoluminescent dosimeter (TLD)-albedo dosimeters to record the neutron dose equivalent received by workers. The energy dependence of the TLD-albedo dosimeter has been recognized and documented since introduced at Hanford in 1964 and numerous studies have helped assure the accuracy of dosimeters. With the recent change in Hanford's mission, there has been a significant decrease in the handling of plutonium tetrafluoride, and an increase in the handling of plutonium metal and plutonium oxide sources. This study was initiated to document the performance of the current Hanford TLD-albedo dosimeter under the low scatter conditions of the calibration laboratory and under the high scatter conditions in the work place under carefully controlled conditions at the Plutonium Finishing Plant (PFP). The neutron fields at the PFP facility were measured using a variety of instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters. Various algorithms were used to evaluate the TLD-albedo dosimeters, and the results are given in this report. Using current algorithms, the dose equivalents evaluated for bare sources and sources with less than 2.5 cm (1 in.) of acrylic plastic shielding in high scatter conditions typical of glove box operations are reasonably accurate. Recently developed CR-39 track etch dosimeters (TEDs) were also exposed in the calibration laboratory and at the PFP. The results indicate that the TED dosimeters are quite accurate for both bare and moderated neutron sources. Until personnel dosimeter is available that incorporates a direct measure of the neutron dose to a person, technical uncertainties in the accuracy of the recorded data will continue

  10. Response of TLD-albedo and nuclear track dosimeters exposed to plutonium sources

    Energy Technology Data Exchange (ETDEWEB)

    Brackenbush, L.W.; Baumgartner, W.V.; Fix, J.J.

    1991-12-01

    Neutron dosimetry has been extensively studied at Hanford since the mid-1940s. At the present time, Hanford contractors use thermoluminescent dosimeter (TLD)-albedo dosimeters to record the neutron dose equivalent received by workers. The energy dependence of the TLD-albedo dosimeter has been recognized and documented since introduced at Hanford in 1964 and numerous studies have helped assure the accuracy of dosimeters. With the recent change in Hanford`s mission, there has been a significant decrease in the handling of plutonium tetrafluoride, and an increase in the handling of plutonium metal and plutonium oxide sources. This study was initiated to document the performance of the current Hanford TLD-albedo dosimeter under the low scatter conditions of the calibration laboratory and under the high scatter conditions in the work place under carefully controlled conditions at the Plutonium Finishing Plant (PFP). The neutron fields at the PFP facility were measured using a variety of instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters. Various algorithms were used to evaluate the TLD-albedo dosimeters, and the results are given in this report. Using current algorithms, the dose equivalents evaluated for bare sources and sources with less than 2.5 cm (1 in.) of acrylic plastic shielding in high scatter conditions typical of glove box operations are reasonably accurate. Recently developed CR-39 track etch dosimeters (TEDs) were also exposed in the calibration laboratory and at the PFP. The results indicate that the TED dosimeters are quite accurate for both bare and moderated neutron sources. Until personnel dosimeter is available that incorporates a direct measure of the neutron dose to a person, technical uncertainties in the accuracy of the recorded data will continue.

  11. Response of TLD-albedo and nuclear track dosimeters exposed to plutonium sources

    Energy Technology Data Exchange (ETDEWEB)

    Brackenbush, L.W.; Baumgartner, W.V.; Fix, J.J.

    1991-12-01

    Neutron dosimetry has been extensively studied at Hanford since the mid-1940s. At the present time, Hanford contractors use thermoluminescent dosimeter (TLD)-albedo dosimeters to record the neutron dose equivalent received by workers. The energy dependence of the TLD-albedo dosimeter has been recognized and documented since introduced at Hanford in 1964 and numerous studies have helped assure the accuracy of dosimeters. With the recent change in Hanford's mission, there has been a significant decrease in the handling of plutonium tetrafluoride, and an increase in the handling of plutonium metal and plutonium oxide sources. This study was initiated to document the performance of the current Hanford TLD-albedo dosimeter under the low scatter conditions of the calibration laboratory and under the high scatter conditions in the work place under carefully controlled conditions at the Plutonium Finishing Plant (PFP). The neutron fields at the PFP facility were measured using a variety of instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters. Various algorithms were used to evaluate the TLD-albedo dosimeters, and the results are given in this report. Using current algorithms, the dose equivalents evaluated for bare sources and sources with less than 2.5 cm (1 in.) of acrylic plastic shielding in high scatter conditions typical of glove box operations are reasonably accurate. Recently developed CR-39 track etch dosimeters (TEDs) were also exposed in the calibration laboratory and at the PFP. The results indicate that the TED dosimeters are quite accurate for both bare and moderated neutron sources. Until personnel dosimeter is available that incorporates a direct measure of the neutron dose to a person, technical uncertainties in the accuracy of the recorded data will continue.

  12. Personnel neutron dosimetry using electrochemically etched CR-39 foils

    International Nuclear Information System (INIS)

    Hankins, D.E.; Homann, S.; Westermark, J.

    1986-01-01

    A personnel neutron dosimetry system has been developed based on the electrochemical etching of CR-39 plastic at elevated temperatures. The doses obtained using this dosimeter system are more accurate than those obtained using other dosimetry systems, especially when varied neutron spectra are encountered. This Cr-39 dosimetry system does not have the severe energy dependence that exists with albedo neutron dosimeters or the fading and reading problems encountered with NTA film. The dosimetry system employs an electrochemical etch procedure that be used to process large numbers of Cr-39 dosimeters. The etch procedure is suitable for operations where the number of personnel requires that many CR-39 dosimeters be processed. Experience shows that one full-time technician can etch and evaluate 2000 foils per month. The energy response to neutrons is fairly flat from about 80 keV to 3.5 MeV, but drops by about a factor of three in the 13 to 16 MeV range. The sensitivity of the dosimetry system is about 7 tracks/cm 2 /mrem, with a background equivalent to about 8 mrem for new CR-39 foils. The limit of sensitivity is approximately 10 mrem. The dosimeter has a significant variation in directional dependence, dropping to about 20% at 90 0 . This dosimeter has been used for personnel neutron dosimetry at the Lawrence Livermore National Laboratory for more tha 18 months. 6 refs., 23 figs., 2 tabs

  13. Area monitoring dosimeter program for the Pacific Northwest National Laboratory: Results for CY 1997

    International Nuclear Information System (INIS)

    Bivins, S.R.; Stoetzel, G.A.

    1998-07-01

    In January 1993, Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the US Department of Energy (DOE) Radiological Control Manual (RCM). The purpose of the program was to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a) (1)--(3) and Article 511.1 of the RCM, personnel dosimetry shall be provided to (1) radiological workers who are likely to receive at least 100 mrem annually, and (2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years (CY) 1993--1996 confirmed that personnel dosimetry was not needed for individuals located in areas monitored by the program. A total of 93 area thermoluminescent dosimeters (TLDs) were placed in PNNL facilities during CY 1997. The TLDs were exchanged and analyzed quarterly. All routine area monitoring TLD results were less than 50 mrem annually after correcting for worker occupancy. The results support the conclusions that personnel dosimeters are not necessary for staff, declared pregnant workers, minors, or members of the public in these monitored areas

  14. Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 1998

    International Nuclear Information System (INIS)

    GA Stoetzel; SR Bivins

    1999-01-01

    In January 1993, Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM). The purpose of the program was to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a)(1)-(4) and Article 511.1 of the RCM, personnel dosimetry shall be provided to (1) radiological workers who are likely to receive at least 100 mrem annually and (2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-1997 confirmed that personnel dosimetry was not needed for individuals located in areas monitored by the program. A total of 97 area thermoluminescent dosimeters (TLDs) were placed in PNNL facilities during calendar year 1998. The TLDs were exchanged and analyzed quarterly. All routine area monitoring TLD results were less than 50 mrem annually after correcting for worker occupancy. The results support the conclusion that personnel dosimeters are not necessary for staff, declared pregnant workers, minors, or members of the public in these monitored areas

  15. Do you know DIS? a novel passive individual dosimeterd. Direct Ion Storage dosimeter DIS-1 officially approved in Switzerland

    International Nuclear Information System (INIS)

    Fiechtner, A.; Wernli, C.

    2001-01-01

    For individual monitoring film and TLD are the most often used types of dosimeters. On a smaller scale phosphate glasses and detectors based on optically stimulated luminescence (OSL) are also in use. As a new addition to the list of available personnel dosimeters the direct ion storage (DIS) system became legally approved for the first time in Switzerland. At the Paul Scherrer Institute (PSI) the RADOS dosimetry system DIS-1 is in official use since beginning of 2001. (orig.) [de

  16. Personnel neutron dose assessment upgrade: Volume 1, Personnel neutron dosimetry assessment: [Final report

    International Nuclear Information System (INIS)

    Hadlock, D.E.; Brackenbush, L.W.; Griffith, R.V.; Hankins, D.E.; Parkhurst, M.A.; Stroud, C.M.; Faust, L.G.; Vallario, E.J.

    1988-07-01

    This report provides guidance on the characteristics, use, and calibration criteria for personnel neutron dosimeters. The report is applicable for neutrons with energies ranging from thermal to less than 20 MeV. Background for general neutron dosimetry requirements is provided, as is relevant federal regulations and other standards. The characteristics of personnel neutron dosimeters are discussed, with particular attention paid to passive neutron dosimetry systems. Two of the systems discussed are used at DOE and DOE-contractor facilities (nuclear track emulsion and thermoluminescent-albedo) and another (the combination TLD/TED) was recently developed. Topics discussed in the field applications of these dosimeters include their theory of operation, their processing, readout, and interpretation, and their advantages and disadvantages for field use. The procedures required for occupational neutron dosimetry are discussed, including radiation monitoring and the wearing of dosimeters, their exchange periods, dose equivalent evaluations, and the documenting of neutron exposures. The coverage of dosimeter testing, maintenance, and calibration includes guidance on the selection of calibration sources, the effects of irradiation geometries, lower limits of detectability, fading, frequency of calibration, spectrometry, and quality control. 49 refs., 6 figs., 8 tabs

  17. Improved sample holders for the PMMA dosimeters

    International Nuclear Information System (INIS)

    Kobayashi, Toshikazu; Sone, Koji; Iso, Katsuaki

    1994-01-01

    PMMA dosimeters are widely used for high dose dosimetry. Dose is determined by measuring the change in optical density of the irradiated PMMA dosimeter element. Measurement precision depends on the mounting method of a dosimeter element in the sample room of a spectrophotometer. We tried to prepare three types of holders, (holders A, B and C in Figs. 1-3), according to the shape of PMMA dosimeter elements. We measured optical density of the irradiated PMMA dosimeter elements by using the three types of holders. It is revealed that the holder of the type A gives more precise results for the Red 4034 or Gammachrome YR dosimeter than that of the type B. The measurements with a spectrophotometer using the type C holder gives better results for the Red acrylic dosimeter than the case of the measurements by the exclusive reader. (author)

  18. Epstein–Barr Virus Susceptibility in Activated PI3Kδ Syndrome (APDS Immunodeficiency

    Directory of Open Access Journals (Sweden)

    Jean-Marie Carpier

    2018-01-01

    Full Text Available Activated PI3Kδ Syndrome (APDS is an inherited immune disorder caused by heterozygous, gain-of-function mutations in the genes encoding the phosphoinositide 3-kinase delta (PI3Kδ subunits p110δ or p85δ. This recently described primary immunodeficiency disease (PID is characterized by recurrent sinopulmonary infections, lymphoproliferation, and susceptibility to herpesviruses, with Epstein–Barr virus (EBV infection being most notable. A broad range of PIDs having disparate, molecularly defined genetic etiology can cause susceptibility to EBV, lymphoproliferative disease, and lymphoma. Historically, PID patients with loss-of-function mutations causing defective cell-mediated cytotoxicity or antigen receptor signaling were found to be highly susceptible to pathological EBV infection. By contrast, the gain of function in PI3K signaling observed in APDS patients paradoxically renders these patients susceptible to EBV, though the underlying mechanisms are incompletely understood. At a cellular level, APDS patients exhibit deranged B lymphocyte development and defects in class switch recombination, which generally lead to defective immunoglobulin production. Moreover, APDS patients also demonstrate an abnormal skewing of T cells toward terminal effectors with short telomeres and senescence markers. Here, we review APDS with a particular focus on how the altered lymphocyte biology in these patients may confer EBV susceptibility.

  19. Development of a 32-channel ASIC for an X-ray APD detector onboard the ISS

    Science.gov (United States)

    Arimoto, Makoto; Harita, Shohei; Sugita, Satoshi; Yatsu, Yoichi; Kawai, Nobuyuki; Ikeda, Hirokazu; Tomida, Hiroshi; Isobe, Naoki; Ueno, Shiro; Mihara, Tatehiro; Serino, Motoko; Kohmura, Takayoshi; Sakamoto, Takanori; Yoshida, Atsumasa; Tsunemi, Hiroshi; Hatori, Satoshi; Kume, Kyo; Hasegawa, Takashi

    2018-02-01

    We report on the design and performance of a mixed-signal application specific integrated circuit (ASIC) dedicated to avalanche photodiodes (APDs) in order to detect hard X-ray emissions in a wide energy band onboard the International Space Station. To realize wide-band detection from 20 keV to 1 MeV, we use Ce:GAGG scintillators, each coupled to an APD, with low-noise front-end electronics capable of achieving a minimum energy detection threshold of 20 keV. The developed ASIC has the ability to read out 32-channel APD signals using 0.35 μm CMOS technology, and an analog amplifier at the input stage is designed to suppress the capacitive noise primarily arising from the large detector capacitance of the APDs. The ASIC achieves a performance of 2099 e- + 1.5 e-/pF at root mean square (RMS) with a wide 300 fC dynamic range. Coupling a reverse-type APD with a Ce:GAGG scintillator, we obtain an energy resolution of 6.7% (FWHM) at 662 keV and a minimum detectable energy of 20 keV at room temperature (20 °C). Furthermore, we examine the radiation tolerance for space applications by using a 90 MeV proton beam, confirming that the ASIC is free of single-event effects and can operate properly without serious degradation in analog and digital processing.

  20. Personal neutron dosimeter using solid-state track detector

    International Nuclear Information System (INIS)

    Mettripan, S.

    1980-01-01

    A cellulose nitrate film coated on both sides with lithium tetraborate was used as a neutron dosimeter for surveillance of personnel exposed to thermal and epithermal neutron. It was found that the optimum etching conditions used were 10% solution of sodium hydroxide, 60 degrees C and 20 minutes etching time and the alpha track densities from the (n,α) reaction on the films were proportional to thermal and epithermal neutron fluxes. The response of the film was found to be 1.068 x 10 -3 tracks per thermal neutron and 3.438 x 10 -4 tracks per epithermal neutron

  1. Bronchial dosimeter for radon progeny

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, T.K.; Yu, K.N.; Nikezic, D.; Haque, A.K.M.M. [City University of Hong Kong, Hong Kong (China); Vucic, D. [Faculty of Technology, University of Nis, Lescovac (Yugoslavia)

    2000-05-01

    Traditionally, assessments of the bronchial dose from radon progeny were carried out by measuring the unattached fraction (f{sub p}) of potential alpha energy concentration (PAEC), the total PAEC, activity median diameters (AMDs) and equilibrium factor, and then using dosimetric lung models. A breakthrough was proposed by Hopke et al. (1990) to use multiple metal wire screens to mimic the deposition properties of radon progeny in the nasal (N) and tracheobronchial (T-B) regions directly. In particular, they were successful in using four layers of 400-mesh wire screens with a face velocity of 12 cm s{sup -1} for the simulation of radon progeny deposition in the T-B region. Oberstedt and Vanmarcke (1995) carried out precise calibrations for the system, and named the system as the 'bronchial dosimeter'. Based on these, Yu and Guan (1998) proposed a portable bronchial dosimeter similar to a normal measurement system for radon progeny or PAEC and consisted of only a single sampler and employed only one 400-mesh wire screen and one filter. However, all these 'bronchial dosimeters' in fact only determined the fraction of potential alpha energy from radon progeny deposited in the T-B region, which required certain assumptions and calculations to further give the final bronchial dose. In the present work, a true 'bronchial dosimeter' was designed, which consisted of three 400-mesh wire screens and a filter. With a face velocity of 11 cm s{sup -1}, the deposition pattern on the wire screens was found to satisfactorily match the variation of the dose conversion factor (in the unit of mSv/WLM) with the size of radon progeny from 1 to 1000 nm. In this way, this bronchial dosimeter directly gave the bronchial dose from the alpha counts recorded on the wire-screens and the filter paper. With the development of this bronchial dosimeter, the present practice of 'dose estimation' from large-scale radon surveys can be replaced by large

  2. Operation of Personal Electronic Dosimeters at NRCN

    International Nuclear Information System (INIS)

    Weinstein, M.; Abraham, A.; Tshuva, A.; German, U.

    2004-01-01

    In the recent years, electronic personal dosimeters (EPD's) are increasingly being used at NRCN, replacing the old direct reading dosimeters that are still widely used. The most significant advantage of the new dosimeters is the real time alarm in a radiation field exceeding a pre-determined threshold. The EPD dosimeters are more precise and can measure γ, β and x rays of a wide range of energies. In addition, the electronic dosimeters collects and stores the reading at a fixed pattern (every 10 seconds) and keeps the data until it is downloaded from the dosimeter. This feature gives the ability to build a personal time-dependent exposure report for each worker who carries this device and to analyze, identify and measure the exact dose, time and duration of any exposure event he was involved in. Designing and building a personal electronic dosimeter became possible as a result of the massive technological improvements of semi conductor detectors and the minimization processes of microprocessors and low energy electronic devices. The main purpose for personal electronic dosimeters was to monitor on-line doses for radiation workers.A special reader device enables to download data and upload operational settings of the dosimeters. By means of this communication channel, one can save the data acquired by the dosimeter, clear the dosimeter memory and set the dosimeter operational parameters. There are two possible working patterns. The first is to read and set all the dosimeters at a central point, normally a dosimetry laboratory (single reader) and the second and more expensive one, is to build a network of readers covering the plant for obtaining on-line communication

  3. Development of colored alumilite dosimeter

    CERN Document Server

    Obara, K; Yagi, T; Yokoo, N

    2003-01-01

    In the ITER (International Thermonuclear Experimental Reactor), in-vessel components such as blanket and divertor, which are installed in the vacuum vessel of the ITER, are maintained by remote handling equipment (RH equipment). The RH equipment for maintenance is operated under sever environmental conditions, such as high temperature (50 approx 100 degC), high gamma-ray radiation (approx 1 kGy/h) in an atmosphere of inert gas or vacuum; therefore many components of the RH equipment must have a suitable radiation resistance efficiency for long time operation (10 approx 100 MGy). Typical components of the RH equipment have been extensively tested under an intensive gamma-ray radiation. Monitoring of the radiation dose of the components of the RH equipment is essential to control the operation period of the RH equipment considering radiation resistance. However, the maximum measurable radiation dose of the conventional dosimeters, such as ionization chamber, liquid, glass and plastic dosimeters are limited to b...

  4. RADIATION DOSIMETER AND DOSIMETRIC METHODS

    Science.gov (United States)

    Taplin, G.V.

    1958-10-28

    The determination of ionizing radiation by means of single fluid phase chemical dosimeters of the colorimetric type is presented. A single fluid composition is used consisting of a chlorinated hydrocarbon, an acidimetric dye, a normalizer and water. Suitable chlorinated hydrocarbons are carbon tetrachloride, chloroform, trichloroethylene, trichlorethane, ethylene dichioride and tetracbloroethylene. Suitable acidimetric indicator dyes are phenol red, bromcresol purple, and creosol red. Suitable normallzers are resorcinol, geraniol, meta cresol, alpha -tocopberol, and alpha -naphthol.

  5. Approving of personal dosimeter services

    International Nuclear Information System (INIS)

    Bergman, K.; Malmqvist, L.

    2001-09-01

    The Swedish regulation SSI FS 98:5 requires that radiological workers of category A use dosemeters from an approved personal dosimetry service. The regulation also includes certain specific dosimeter requirements, which are based on those presented in the Technical Recommendations by the European Commission (Report EUR 14852 EN, 1994). All services have been tested for their ability to determine Hp(10) and some of them to determine Hp(0.07) at one radiation quality. The test was performed in the interval 0.2 mSv to 100 mSv at three different dose equivalents unknown to the system owner. The 11 services operating in Sweden at the moment use 5 different types of dosimeters. The five unique systems have been tested regarding the angular and energy dependence of the response of the dosimeters. The dosimeters were irradiated to a personal dose equivalent of about 1 mSv at three photon energies and at four angles (0, 20, 40 and 60 deg. resp. ) both vertically and horizontally rotated. Only 2 of the services determine Hp(0.07) for beta and gamma radiation and were tested for this quantity. The test results for Hp(10) are all except two within the trumpet curve. For the unique systems it is shown that the uncertainty related to angular response at a specified energy is within the required ±40 % except for the lowest X-ray quality at 40 kV. The response is more dependent on photon energy than on the direction of the photon radiation and the choice of radiation quality for the calibration is of great importance for the system performance

  6. Radiation sensitive polymer gel dosimeters

    International Nuclear Information System (INIS)

    Lepage, M.; Back, S.A.J.; Baldock, C.; Whittaker, A.K.; Rintoul, L.

    2000-01-01

    Full text: Radiation sensitive gels are studied for their potential to retain a permanent 3D dose distribution for applications in radiotherapy. Co-monomers dissolved in a tissue-equivalent hydrogel undergo a polymerization reaction upon absorption of ionizing radiation. The polymer formed influences the local spin-spin relaxation time (T 2 ) of the dosimeter that can be determined using magnetic resonance imaging (MRI). The relationship between T2 and the absorbed dose was studied for different initial chemical compositions. The aim was to find a model linking the changes in T 2 with absorbed dose to the initial composition of the dosimeter. It is believed this will help designing new gel dosimeters having desired properties to minimize the uncertainty in the determination of the dose distribution. 1 H, 13 C nuclear magnetic resonance spectroscopy and FT-Raman spectroscopy were used to quantify the amount of monomers still remaining after the absorption of a given dose of radiation. This data is used to model the changes of T2 as a function of the absorbed dose. A model of fast exchange of magnetization between three proton pools was used, where the fraction of protons (f x H ) in the x th pool is obtained from the chemical composition of the dosimeter and the apparent T2 of each pool is determined for a given composition. Initially, the protons are contained in two pools; a mobile (mob), which contains the water protons and the monomers protons, and a gelatin (gela) proton pool. The mobile pool is partially depleted as polymer is formed, the protons are transferred into the polymer (pol) pool. In the figure, the experimental data along with the calculated values are plotted for three different monomer concentrations, with the gelatin concentration fixed. The model is seen to provide a good fit to the experimental data

  7. Area Monitoring Dosimeter Program for the Pacific Northwest National Laboratory: Results for CY 2000

    International Nuclear Information System (INIS)

    Bivins, Steven R; Stoetzel, Gregory A

    2001-01-01

    Pacific Northwest National Laboratory (PNNL) established an area monitoring dosimeter program in accordance with Article 514 of the Department of Energy (DOE) Radiological Control Manual (RCM) in January 1993. This program is to minimize the number of areas requiring issuance of personnel dosimeters and to demonstrate that doses outside Radiological Buffer Areas are negligible. In accordance with 10 CFR Part 835.402 (a) (1)-(4) and Article 511.1 of the DOE Standard Radiological Control, personnel dosimetry shall be provided to (1) radiological workers who are likely to receive at least 100 mrem annually, and (2) declared pregnant workers, minors, and members of the public who are likely to receive at least 50 mrem annually. Program results for calendar years 1993-2000 confirm that personnel dosimetry is not needed for individuals located in areas monitored by the program

  8. Neutron dosimetry at commercial nuclear plants. Final report of Subtask B: dosimeter response

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, F.M.; Endres, G.W.R.; Brackenbush, L.W.

    1983-03-01

    As part of a larger program to evaluate personnel neutron dosimetry at commercial nuclear power plants, this study was designed to characterize neutron dosimeter responses inside the containment structure of commercial nuclear plants. In order to characterize those responses, dosimeters were irradiated inside containment at 2 pressurized water reactors and at pipe penetrations outside the biological shield at two boiling water reactors. The reactors were operating at full power during the irradiations. Measurements were also performed with electronic instruments, the tissue equivalent proportional counter (TEPC), and portable remmeters, SNOOPY, RASCAL and PNR-4.

  9. Automation of dosimeters calibration for radiotherapy in secondary dosimetric calibration laboratory of the CPHR

    International Nuclear Information System (INIS)

    Acosta, Andy L. Romero; Lores, Stefan Gutierrez

    2013-01-01

    This paper presents the design and implementation of an automated system for measurements in the calibration of reference radiation dosimeters. It was made a software application that performs the acquisition of the measured values of electric charge, calculated calibration coefficient and automates the calibration certificate issuance. These values are stored in a log file on a PC. The use of the application improves control over the calibration process, helps to humanize the work and reduces personnel exposure. The tool developed has been applied to the calibration of dosimeters radiation patterns in the LSCD of the Centro de Proteccion e Higiene de las Radiaciones, Cuba

  10. Neutron dosimetry at commercial nuclear plants. Final report of Subtask B: dosimeter response

    International Nuclear Information System (INIS)

    Cummings, F.M.; Endres, G.W.R.; Brackenbush, L.W.

    1983-03-01

    As part of a larger program to evaluate personnel neutron dosimetry at commercial nuclear power plants, this study was designed to characterize neutron dosimeter responses inside the containment structure of commercial nuclear plants. In order to characterize those responses, dosimeters were irradiated inside containment at 2 pressurized water reactors and at pipe penetrations outside the biological shield at two boiling water reactors. The reactors were operating at full power during the irradiations. Measurements were also performed with electronic instruments, the tissue equivalent proportional counter (TEPC), and portable remmeters, SNOOPY, RASCAL and PNR-4

  11. measurement of the supralinearity of 7LiF thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    Hancock, I.B.

    1978-04-01

    A study has been made of the supralinearity of the 7 LiF thermoluminesecent dosimeter (T.L.D.) used in the UKAEA personnel criticality dosimeter by exposure to a 60 Co source. the response of the T.L.D. was linear up to approximately 450 rad, above which it became increasingly supralinear, over-reading by about 50% at 2000 rad. The results have been used to produce a correction graph, as a function of apparent dose up to 3500 rad, for routine use in nuclear accident dosimetry. (author)

  12. The status of ANSI N13.11 - The dosimeter performance test standard

    International Nuclear Information System (INIS)

    Sims, C.S.

    1991-01-01

    The standard designated ANSI N13.11 was issued in 1983 and is the basis for the dosimeter performance test associated with the National Voluntary Laboratory Accreditation Program (NVLAP). The standard is important because the Nuclear Regulatory Commission requires that all licensees use personnel dosimeters processed by NVLAP-accredited processors. The standard has undergone review and modifications have been recommended. Historical information concerning the development and utilization of the present standard, ANSI N13.11-1983, is presented. Details associated with the review of the standard (e.g., policy, group selection) are then given. Finally, the modifications recommended by the review group are discussed

  13. Survey of international personnel radiation dosimetry programs

    International Nuclear Information System (INIS)

    Swaja, R.E.

    1985-04-01

    In September of 1983, a mail survey was conducted to determine the status of external personnel gamma and neutron radiation dosimetry programs at international agencies. A total of 130 agencies participated in this study including military, regulatory, university, hospital, laboratory, and utility facilities. Information concerning basic dosimeter types, calibration sources, calibration phantoms, corrections to dosimeter responses, evaluating agencies, dose equivalent reporting conventions, ranges of typical or expected dose equivalents, and degree of satisfaction with existing systems was obtained for the gamma and neutron personnel monitoring programs at responding agencies. Results of this survey indicate that to provide the best possible occupational radiation monitoring programs and to improve dosimetry accuracy in performance studies, facility dosimetrists, regulatory and standards agencies, and research laboratories must act within their areas of responsibility to become familiar with their radiation monitoring systems, establish common reporting guidelines and performance standards, and provide opportunities for dosimetry testing and evaluation. 14 references, 10 tables

  14. Argentine Republic intercomparison programme for personal dosimeters

    International Nuclear Information System (INIS)

    Gregori, Beatriz N.; Papadopulos, Susana B.; Kunst, Juan J.; Cruzate, Juan A.; Saravi, Margarita C.

    2004-01-01

    In 1997 an Intercomparison Program for individual monitoring started in order to test (on a voluntary basis) the performance in absorbed dose and personal dose equivalent determinations. The aim of the program was also to gain some insight into the general aspects related to the type of the personnel dosimeter used, the calibration procedures, the phantom spectral dependence and the management of radiological quantities. The Regional Reference Center for Dosimetry (CCR), of the Argentine National Atomic Energy Commission and the Physical Dosimetry Laboratory of the Argentine National Regulatory Authority, performed the irradiations. Those were done free air and on ICRU phantom, using X-ray, quality ISO: W60, W80, W110 and W200; and 137 Cs and 60 Co gamma rays, normal and angular (0, 30, 60 degrees) incidence. In the framework of the Program, an upgraded workshop took place and the national standard, IRAM 17146, was elaborated as well. In this work, the laboratories performance and its temporal evolution is shown from 1997 up to 2002. The suggestions to improve their performance are also included. (author)

  15. Interim status report of the TMI personnel-dosimetry project

    International Nuclear Information System (INIS)

    Rich, B.L.; Alvarez, J.L.; Adams, S.R.

    1981-06-01

    The current 2-chip TLD personnel dosimeter in use at Three Mile Island (TMI) has been shown inadequate for the anticipated high beta/gamma fields during TMI recovery operations in some areas. This project surveyed the available dosimeter systems, set up an Idaho National Engineering Laboratory (INEL) prototype system, and compared this system with those commercial systems that could be made immediately available for comparison. Of the systems tested, the new INEL personnel dosimeter was found to produce the most accurate results for use in recovery operations at TMI-2. The other multiple-chip or multiple-filter systems were found less desirable at present. The most prominent deficiencies in the INEL dosimeter stem from the fact that it lacks a completely automated reader and its x-ray and thermal neutron responses require additional development. A automated prototype reader system may be in operation by the end of CY-1981. Three alternatives for operational dosimetry are discussed. A combination of a modified version of the presently used Harshaw 2-chip dosimeter and the INEL dosimeter is recommended

  16. Acoustic evaluation of polymer gel dosimeters

    International Nuclear Information System (INIS)

    Mather, M.L.; De Deene, Y.; Baldock, C.; Whittaker, A.K.

    2002-01-01

    Advances in radiotherapy treatment techniques such as intensity modulated radiotherapy are placing increasing demands on radiation dosimetry for verification of dose distributions in 3D. In response, polymer gel dosimeters that are capable of recording dose distributions in 3D are currently being developed. Recently, a new technique for evaluation of absorbed dose distributions in these dosimeters using ultrasound was introduced. The current work aims to demonstrate the potential of ultrasound as an evaluation technique for polymer gel dosimeters and to investigate the ultrasound properties of two different dosimeter formulations, PAG and MAGIC gels

  17. Fast-neutron solid-state dosimeter

    International Nuclear Information System (INIS)

    Kecker, K.H.; Haywood, F.F.; Perdue, P.T.; Thorngate, J.H.

    1975-01-01

    This patent relates to an improved fast-neutron solid-state dosimeter that does not require separation of materials before it can be read out, that utilizes materials that do not melt or otherwise degrade at about 300 0 C readout temperature, that provides a more efficient dosimeter, and that can be reused. The dosimeters are fabricated by intimately mixing a TL material, such as CaSO 4 :Dy, with a powdered polyphenyl, such as p-sexiphenyl, and hot-pressing the mixture to form pellets, followed by out-gassing in a vacuum furnace at 150 0 C prior to first use dosimeters

  18. Personnel Preparation.

    Science.gov (United States)

    Fair, George, Ed.; Stodden, Robert, Ed.

    1981-01-01

    Three articles comprise a section on personnel preparation in vocational education. Articles deal with two inservice programs in career/vocational education for the handicapped and a project to train paraprofessionals to assist special educators in vocational education. (CL)

  19. Development of colored alumilite dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Obara, Kenjiro; Shibanuma, Kiyoshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Yagi, Toshiaki [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Yokoo, Noriko [Radiation Application Development Association, Tokai, Ibaraki (Japan)

    2003-03-01

    In the ITER (International Thermonuclear Experimental Reactor), in-vessel components such as blanket and divertor, which are installed in the vacuum vessel of the ITER, are maintained by remote handling equipment (RH equipment). The RH equipment for maintenance is operated under sever environmental conditions, such as high temperature (50{approx}100 degC), high gamma-ray radiation ({approx}1 kGy/h) in an atmosphere of inert gas or vacuum; therefore many components of the RH equipment must have a suitable radiation resistance efficiency for long time operation (10{approx}100 MGy). Typical components of the RH equipment have been extensively tested under an intensive gamma-ray radiation. Monitoring of the radiation dose of the components of the RH equipment is essential to control the operation period of the RH equipment considering radiation resistance. However, the maximum measurable radiation dose of the conventional dosimeters, such as ionization chamber, liquid, glass and plastic dosimeters are limited to be approximately 1MGy which is too low to monitor the RH equipment for the ITER. In addition, these conventional dosimeters do not involve sufficient radiation resistance against the high gamma-ray radiation as well as are not easy handling and low cost. Based on the above backgrounds, a new dosimeter with bleaching of an azo group dye to be applied to a radiation monitor has been developed for high gamma-ray radiation use. The colored alumilite dosimeter is composed of the azo group dye (-N=N-) in an anodic oxidation layer of aluminum alloy (Al{sub 2}O{sub 3}). It can monitor the radiation dose by measuring the change of the bleaching of azo dye in the Al{sub 2}O{sub 3} layer due to gamma-ray irradiation. The degree of bleaching is measured as the change of hue (color) and brightness based on the Munsell's colors with a three dimensional universe using spectrophotometer. In the tests, the dependencies such as colors, anodized layer thickness, type of azo

  20. A method to stabilize the temperature dependent performance of G-APD arrays

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Yoonsuk [Molecular Imaging Research and Education (MiRe) Laboratory, Department of Electronic Engineering, Sogang University, Seoul (Korea, Republic of); Sungkyunkwan University, School of Medicine, Seoul (Korea, Republic of); Choi, Yong; Ho Jung, Jin; Jung, Jiwoong [Molecular Imaging Research and Education (MiRe) Laboratory, Department of Electronic Engineering, Sogang University, Seoul (Korea, Republic of)

    2015-02-01

    This paper presents a compensation method to stabilize the temperature dependent performance of Geiger-mode Avalanche Photodiode (G-APD) arrays for Positron Emission Tomography (PET). The compensation method is used to identify the bias voltage range that provides stable performance even at different temperatures using the G-APD’s characteristics, and to control the photo-peak variation as a function of temperature using the preamplifier gain within the identified bias voltage range. A pair of G-APD detectors and temperature sensors were located in the temperature chamber and the preamplifiers which can control the gain of the detectors using the digital potentiometer were positioned outside the chamber. The performance of the G-APD detector, especially energy resolution and coincidence timing resolution, was characterized as a function of bias voltage at different temperatures from 20 °C to 40 °C at 5 °C increments; the energy resolution, coincidence timing resolution, and photo-peak position of all channels of G-APD PET detectors before and after the preamplifier gain correction were then measured and compared. The results of this study demonstrated that the optimal bias voltage range providing the good energy and coincidence timing resolution, 12.1±1.2% and 1.30±0.09 ns, respectively, could be identified at the temperature range and the photo-peak variation and the performance at different temperatures could be stabilized by adjusting the preamplifier gain within the identified bias voltage range. We concluded the proposed method to be reliable and useful for the development of the PET system using G-APD arrays.

  1. A PC based thin film dosimeter system

    DEFF Research Database (Denmark)

    Miller, A.; Hargittai, P.; Kovacs, A.

    2000-01-01

    A dosimeter system based on the Riso B3 dosimeter film, an office scanner for use with PC and the associated software is presented. The scanned image is analyzed either with standard software (Paint Shop Pro 5 or Excel) functions or with the computer code "Scanalizer" that allows presentation...

  2. A personal radio-frequency dosimeter with cumulative-dose recording capabilities

    International Nuclear Information System (INIS)

    Rochelle, R.W.; Moore, M.R.; Thomas, R.S.; Ewing, P.D.; Hess, R.A.; Hoffheins, B.S.

    1990-01-01

    The radio-frequency (rf) dosimeter developed by the Oak Ridge National Laboratory is a portable, pocket-sized cumulative-dose recording device designed to detect and record the strengths and durations of electric fields present in the work areas of naval vessels. The device measures an integrated dose and records the electric fields that exceed the permissible levels set by the American National Standards Institute. Features of the rf dosimeter include a frequency range of 30 MHz to 10 GHz and a three-dimensional sensor. Data obtained with the rf dosimeter will be used to determine the ambient field-strength profile for shipboard personnel over an extended time. Readings are acquired and averaged over a 6-min period corresponding to the rise time of the core body temperature. These values are stored for up to 6 months, after which the data are transferred to a computer via the dosimeter's serial port. The rf dosimeter should increase knowledge of the levels of electric fields to which individuals are exposed. 13 refs., 16 figs., 2 tabs

  3. Study on APD real time compensation methods of laser Detection system

    International Nuclear Information System (INIS)

    Feng Ying; Zhang He; Zhang Xiangjin; Liu Kun

    2011-01-01

    With the monochromatic and the directional capability of the laser, laser detection system is confidential in anti-jamming. Detection accuracy is improved significantly as the result of laser's good orientation ability. Sensitivity is enhanced as laser's high-brightness characteristic. With the development of laser technology and laser devices, laser detections are developed both in civilian and military areas. In the military field, laser detection system has been widely applied in various types of tactical missiles, the technique is more mature. Because photo detectors receive the backscattering echo signal of target in laser detection system, they are required sensitive enough to weak signal. With APD's salient features of high sensitivity, rapid response speed, high response frequency and low noise equivalent power, etc.; PIN is replaced by APD to improve sensitivity of laser detection system in recent years. The signal magnification is inadequate in laser detection system, the detector output is usually amplified by multistage amplifiers. And then the system noise includes detector noise and latter amplifiers noise. With its high internal gain, APD becomes the primary noise source of receiving system. This point can be attested by analyzing the transfer function of laser detection system receiver. To ensure the system detecting ability, APD noise must be mitigated as low as possible. According to a large number of experiments, the power signal-to-noise (SNR) and the best multiplication factor of APD are mostly affected by background radiation and temperature. In order to make APD operate at state of the best multiplication factor, the optimum bias must be selected due to the actual operating circumstance. Therefore, APD realtime compensation must be adopted. The existing APD compensation includes the constant false alarm rate compensation, the noise compensation and the temperature compensation. The features of these compensations are obtained by analyzing

  4. Study on APD real time compensation methods of laser Detection system

    Energy Technology Data Exchange (ETDEWEB)

    Feng Ying; Zhang He; Zhang Xiangjin; Liu Kun, E-mail: fy_caimi@163.com [ZNDY of Ministerial Key Laboratory, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2011-02-01

    With the monochromatic and the directional capability of the laser, laser detection system is confidential in anti-jamming. Detection accuracy is improved significantly as the result of laser's good orientation ability. Sensitivity is enhanced as laser's high-brightness characteristic. With the development of laser technology and laser devices, laser detections are developed both in civilian and military areas. In the military field, laser detection system has been widely applied in various types of tactical missiles, the technique is more mature. Because photo detectors receive the backscattering echo signal of target in laser detection system, they are required sensitive enough to weak signal. With APD's salient features of high sensitivity, rapid response speed, high response frequency and low noise equivalent power, etc.; PIN is replaced by APD to improve sensitivity of laser detection system in recent years. The signal magnification is inadequate in laser detection system, the detector output is usually amplified by multistage amplifiers. And then the system noise includes detector noise and latter amplifiers noise. With its high internal gain, APD becomes the primary noise source of receiving system. This point can be attested by analyzing the transfer function of laser detection system receiver. To ensure the system detecting ability, APD noise must be mitigated as low as possible. According to a large number of experiments, the power signal-to-noise (SNR) and the best multiplication factor of APD are mostly affected by background radiation and temperature. In order to make APD operate at state of the best multiplication factor, the optimum bias must be selected due to the actual operating circumstance. Therefore, APD realtime compensation must be adopted. The existing APD compensation includes the constant false alarm rate compensation, the noise compensation and the temperature compensation. The features of these compensations are obtained

  5. Study on APD real time compensation methods of laser Detection system

    Science.gov (United States)

    Ying, Feng; He, Zhang; Xiangjin, Zhang; Kun, Liu

    2011-02-01

    With the monochromatic and the directional capability of the laser, laser detection system is confidential in anti-jamming. Detection accuracy is improved significantly as the result of laser's good orientation ability. Sensitivity is enhanced as laser's high-brightness characteristic. With the development of laser technology and laser devices, laser detections are developed both in civilian and military areas. In the military field, laser detection system has been widely applied in various types of tactical missiles, the technique is more mature. Because photo detectors receive the backscattering echo signal of target in laser detection system, they are required sensitive enough to weak signal. With APD's salient features of high sensitivity, rapid response speed, high response frequency and low noise equivalent power, etc.; PIN is replaced by APD to improve sensitivity of laser detection system in recent years. The signal magnification is inadequate in laser detection system, the detector output is usually amplified by multistage amplifiers. And then the system noise includes detector noise and latter amplifiers noise. With its high internal gain, APD becomes the primary noise source of receiving system. This point can be attested by analyzing the transfer function of laser detection system receiver. To ensure the system detecting ability, APD noise must be mitigated as low as possible. According to a large number of experiments, the power signal-to-noise (SNR) and the best multiplication factor of APD are mostly affected by background radiation and temperature. In order to make APD operate at state of the best multiplication factor, the optimum bias must be selected due to the actual operating circumstance. Therefore, APD realtime compensation must be adopted. The existing APD compensation includes the constant false alarm rate compensation, the noise compensation and the temperature compensation. The features of these compensations are obtained by analyzing

  6. Angular dependence of dose equivalent response of an albedo neutron dosimeter

    International Nuclear Information System (INIS)

    Torres, B.A.; Boswell, E.; Schwartz, R.B.

    1994-01-01

    The ANSI provides procedures for testing the performance of dosimetry services. Although neutron dose equivalent angular response studies are not now mandated, future standards may well require that such studies be performed. Current studies with an albedo dosimeter will yield information regarding the angular dependence of dose equivalent response for this type of personnel dosimeter. Preliminary data for bare 252 Cf fluences show a marked decrease in dosimeter reading with increasing angle. The response decreased by an approximate factor of four. For the horizontal orientation, the same response was noted from both positive and negative angles. However, for the vertical orientation, the response was unexplainably assymetric. We are also examining the response of the personnel badge in moderated 252 Cf fluences. Responses from the moderated and unmoderated 252 Cf fields and theoretical calculations of the neutron angular response will be compared. This information will assist in building a data base for future comparisons of neutron angular responses with other neutron albedo dosimeters and phantoms

  7. Electronics for the camera of the First G-APD Cherenkov Telescope (FACT) for ground based gamma-ray astronomy

    International Nuclear Information System (INIS)

    Anderhub, H; Biland, A; Boller, A; Braun, I; Commichau, V; Djambazov, L; Dorner, D; Gendotti, A; Grimm, O; Gunten, H P von; Hildebrand, D; Horisberger, U; Huber, B; Kim, K-S; Krähenbühl, T; Backes, M; Köhne, J-H; Krumm, B; Bretz, T; Farnier, C

    2012-01-01

    Within the FACT project, we construct a new type of camera based on Geiger-mode avalanche photodiodes (G-APDs). Compared to photomultipliers, G-APDs are more robust, need a lower operation voltage and have the potential of higher photon-detection efficiency and lower cost, but were never fully tested in the harsh environments of Cherenkov telescopes. The FACT camera consists of 1440 G-APD pixels and readout channels, based on the DRS4 (Domino Ring Sampler) analog pipeline chip and commercial Ethernet components. Preamplifiers, trigger system, digitization, slow control and power converters are integrated into the camera.

  8. Development of Thermoluminescence Dosimeter CaSO4:Dy as Personal and Environmental Dosimeters

    International Nuclear Information System (INIS)

    Hasnel Sofyan

    2009-01-01

    Development of personal and environmental dosimeters using material phosphors of CaSO 4 :Dy powder in form capillary glass and disc teflon thermoluminescence (TL) dosimeter have been done. TL dosimeter CaSO 4 :Dy powder used can record dose response less than 0.01 mGy. Fading of TL dosimeter capillary glass after 29 days is 25%. In 1 batch, making of CaSO 4 :Dy powder can obtain 2 groups of dosimeter capillaries with coefficient variance smaller than 10%. This discrepancy caused difference in powder making and reading of the TL dosimeter. TL dosimeter CaSO 4 :Dy teflon disc with dia. 5 mm and 0.8 mm thickness is homogeneous mixture between phosphor powder with dia. 80 to 150 mesh and teflon powder dia. 20 μm. The composition of CaSO 4 :Dy and teflon in TL dosimeter influence sensitivity of the dosimeter. It’ concluded that in order to obtain optimal sensitivity of TL dosimeter, the composition of CaSO 4 :Dy and teflon is 3 and 1 with pressured of disc in 700 MPa. (author).

  9. Scintillation counter based radiation dosimeter

    International Nuclear Information System (INIS)

    Shin, Jeong Hyun

    2009-02-01

    The average human exposure per year is about 240mrem which is come from Radon and human body and terrestrial and cosmic radiation and man-made source. Specially radiation exposure through air from environmental radiation sources is 80mrem/yr(= 0.01mR/hr) which come from Terrestrial and cosmic radiation. Radiation dose is defined as energy deposit/mass. There are two major methods to detect radiation. First method is the energy integration using Air equivalent material like GM counter wall material. Second method is the spectrum to dose conversion method using NaI(Tl), HPGe. These two methods are using generally to detect radiation. But these methods are expensive. So we need new radiation detection method. The research purpose is the development of economical environmental radiation dosimeter. This system consists of Plastic/Inorganic scintillator and Si photo-diode based detector and counting based circuitry. So count rate(cps) can be convert to air exposure rate(R/hr). There are three major advantages in this system. First advantages is no high voltage power supply like GM counter. Second advantage is simple electronics. Simple electronics system can be achieved by Air-equivalent scintillation detector with Al filter for the same detection efficiency vs E curve. From former two advantages, we can know the most important advantages of the this system. Third advantage is economical system. The price of typical GM counter is about $1000. But the price of our system is below $100 because of plastic scintillator and simple electronics. The role of scintillation material is emitting scintillation which is the flash of light produced in certain materials when they absorb ionizing radiation. Plastic scintillator is organic scintillator which is kind of hydrocarbons. The special point are cheap price, large size production(∼ton), moderate light output, fast light emission(ns). And the role of Al filter is equalizing counting efficiency of air and scintillator for

  10. Evaluation of radiation exposure in interventional radiology (IR) using active personal dosimeters (APD); Evaluierung der Strahlenexposition in der Interventionellen Radiologie (IR) mit Hilfe von Aktiv-Personen-Dosimetern (APD)

    Energy Technology Data Exchange (ETDEWEB)

    Neugschwandtner, K. [KH Hietzing mit NZ Rosenhuegel, Wien (Austria). Inst. fuer Krankenhausphysik; TU Wien (Austria). Atominstitut; Freund, R. [KH Hietzing mit NZ Rosenhuegel, Wien (Austria). Inst. fuer Krankenhausphysik; Mertikian, G. [KH Hietzing mit NZ Rosenhuegel, Wien (Austria). Inst. fuer Radiologie; Poljanc, K. [TU Wien (Austria). Atominstitut; Ibi, B. [KA Rudolfstiftung, Wien (Austria). Stabstelle Medizinphysik

    2015-07-01

    Increased awareness of high personal dose exposure of medical staff in interventional radiology (IR) demands an assessment of radiation protection procedures. Mandatory dose monitoring systems do not allow to relate dose to specific actions of the staff as they just accumulate a total dose per month. Doses of head and limbs are expected to be high as those body parts which are not protected by the lead apron. We decided to use a measuring system by Unfors, RaySafe i2 which is built for real- time- dosimetry of scattered radiation in pulsed X-ray fields. An increased dose of the body side closer to the X-ray source (left body side) was detected. This is due to the position and the posture of the radiologist during intervention. Separating the phases of digital subtraction angiography (DSA) from those of fluoroscopy allowed not only to list the separate accumulated doses, but showed as well a big difference in dose rate. The measurements revealed the need of an improvement of common radiation protection, especially while DSA.

  11. Performance testing of extremity dosimeters, Study 2

    International Nuclear Information System (INIS)

    Harty, R.; Reece, W.D.; Hooker, C.D.

    1990-04-01

    The Health Physics Society Standards Committee (HPSSC) Working Group on Performance Testing of Extremity Dosimeters has issued a draft of a proposed standard for extremity dosimeters. The draft standard proposes methods to be used for testing dosimetry systems that determine occupational radiation dose to the extremities and the performance criterion used to determine compliance with the standard. Pacific Northwest Laboratory (PNL) has conducted two separate evaluations of the performance of extremity dosimeter processors to determine the appropriateness of the draft standard, as well as to obtain information regarding the performance of extremity dosimeters. Based on the information obtained during the facility visits and the results obtained from the performance testing, it was recommended that changes be made to ensure that the draft standard is appropriate for extremity dosimeters. The changes include: subdividing the mixture category and the beta particle category; eliminating the neutron category until appropriate flux-to-dose equivalent conversion factors are derived; and changing the tolerance level for the performance criterion to provide consistency with the performance criterion for whole body dosimeters, and to avoid making the draft standard overly difficult for processors of extremity dosimeters to pass. 20 refs., 10 figs., 6 tabs

  12. Dosimetric properties of the pocket alarm dosimeter type Graetz TDW 10/20

    International Nuclear Information System (INIS)

    Hauser, M.; Burgkhardt, B.; Piesch, E.

    1980-08-01

    In personnel monitoring pocket dosimeters with build-in alarm devices are increasingly in use. The report presents results of a test performed at Karlsruhe. The properties investigated are above all linearity and reproducibility of the dose reading as well as of the acustic alarm indication, dependence on the dose reading, the photon energy, the direction of the radiation incidence, the dose rate, the temperature and operational characteristic of the batteries. (orig./HP) [de

  13. Ultraviolet Light Curves of Gaia16apd in Superluminous Supernova Models

    Energy Technology Data Exchange (ETDEWEB)

    Tolstov, Alexey; Zhiglo, Andrey; Nomoto, Ken’ichi; Blinnikov, Sergei [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Sorokina, Elena [Sternberg Astronomical Institute, M.V.Lomonosov Moscow State University, 119234 Moscow (Russian Federation); Kozyreva, Alexandra, E-mail: alexey.tolstov@ipmu.jp [The Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)

    2017-08-10

    Observations of Gaia16apd revealed extremely luminous ultraviolet emission among superluminous supernovae (SLSNe). Using radiation hydrodynamics simulations, we perform a comparison of UV light curves, color temperatures, and photospheric velocities between the most popular SLSN models: pair-instability supernova, magnetar, and interaction with circumstellar medium. We find that the interaction model is the most promising to explain the extreme UV luminosity of Gaia16apd. The differences in late-time UV emission and in color evolution found between the models can be used to link an observed SLSN event to the most appropriate model. Observations at UV wavelengths can be used to clarify the nature of SLSNe and more attention should be paid to them in future follow-up observations.

  14. Radiological manifestations of biphosphonate treatment with APD in a child suffering from osteogenesis imperfecta

    International Nuclear Information System (INIS)

    Devogelaer, J.P.; Deuxchaisnes, C.N. de; Malghem, J.; Maldague, B.

    1987-01-01

    A 12-year-old female suffering fromosteogenesis imperfecta (OI) was treated with 3-amino-1-hydroxypropylidene-1,1-bisphosphonate (APD) orally, 250 mg daily, for periods of 2 months, alternating with periods of 2 months of abstinence. Total duration of therapy was 1 year. Radiological and clinical improvement was striking. Furthermore, X-rays of the bones showed large, parallel radio-opaque striae, corresponding exactly to the periods of therapy. These were present in all metaphyses. (orig.)

  15. Radiological manifestations of biphosphonate treatment with APD in a child suffering from osteogenesis imperfecta

    Energy Technology Data Exchange (ETDEWEB)

    Devogelaer, J.P.; Deuxchaisnes, C.N. de; Malghem, J.; Maldague, B.

    1987-07-01

    A 12-year-old female suffering fromosteogenesis imperfecta (OI) was treated with 3-amino-1-hydroxypropylidene-1,1-bisphosphonate (APD) orally, 250 mg daily, for periods of 2 months, alternating with periods of 2 months of abstinence. Total duration of therapy was 1 year. Radiological and clinical improvement was striking. Furthermore, X-rays of the bones showed large, parallel radio-opaque striae, corresponding exactly to the periods of therapy. These were present in all metaphyses.

  16. Design and performance of single photon APD focal plane arrays for 3-D LADAR imaging

    Science.gov (United States)

    Itzler, Mark A.; Entwistle, Mark; Owens, Mark; Patel, Ketan; Jiang, Xudong; Slomkowski, Krystyna; Rangwala, Sabbir; Zalud, Peter F.; Senko, Tom; Tower, John; Ferraro, Joseph

    2010-08-01

    ×We describe the design, fabrication, and performance of focal plane arrays (FPAs) for use in 3-D LADAR imaging applications requiring single photon sensitivity. These 32 × 32 FPAs provide high-efficiency single photon sensitivity for three-dimensional LADAR imaging applications at 1064 nm. Our GmAPD arrays are designed using a planarpassivated avalanche photodiode device platform with buried p-n junctions that has demonstrated excellent performance uniformity, operational stability, and long-term reliability. The core of the FPA is a chip stack formed by hybridizing the GmAPD photodiode array to a custom CMOS read-out integrated circuit (ROIC) and attaching a precision-aligned GaP microlens array (MLA) to the back-illuminated detector array. Each ROIC pixel includes an active quenching circuit governing Geiger-mode operation of the corresponding avalanche photodiode pixel as well as a pseudo-random counter to capture per-pixel time-of-flight timestamps in each frame. The FPA has been designed to operate at frame rates as high as 186 kHz for 2 μs range gates. Effective single photon detection efficiencies as high as 40% (including all optical transmission and MLA losses) are achieved for dark count rates below 20 kHz. For these planar-geometry diffused-junction GmAPDs, isolation trenches are used to reduce crosstalk due to hot carrier luminescence effects during avalanche events, and we present details of the crosstalk performance for different operating conditions. Direct measurement of temporal probability distribution functions due to cumulative timing uncertainties of the GmAPDs and ROIC circuitry has demonstrated a FWHM timing jitter as low as 265 ps (standard deviation is ~100 ps).

  17. A high granularity plastic scintillator tile hadronic calorimeter with APD readout for a linear collider detector

    Czech Academy of Sciences Publication Activity Database

    Andreev, V.; Cvach, Jaroslav; Danilov, M.; Devitsin, E.; Dodonov, V.; Eigen, G.; Garutti, E.; Gilitzky, Yu.; Groll, M.; Heuer, R.D.; Janata, Milan; Kacl, Ivan; Korbel, V.; Kozlov, V. Yu; Meyer, H.; Morgunov, V.; Němeček, Stanislav; Pöschl, R.; Polák, Ivo; Raspereza, A.; Reiche, S.; Rusinov, V.; Sefkow, F.; Smirnov, P.; Terkulov, A.; Valkár, Š.; Weichert, Jan; Zálešák, Jaroslav

    2006-01-01

    Roč. 564, - (2006), s. 144-154 ISSN 0168-9002 R&D Projects: GA MŠk(CZ) LC527; GA MŠk(CZ) 1P05LA259; GA ČR(CZ) GA202/05/0653 Institutional research plan: CEZ:AV0Z10100502 Keywords : hadronic calorimeter * plastic scintillator tile * APD readout * linear collider detector Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.185, year: 2006

  18. A Novel Time-Based Readout Scheme for a Combined PET-CT Detector Using APDs

    CERN Document Server

    Powolny, F; Hillemanns, H; Jarron, P; Lecoq, P; Meyer, T C; Moraes, D

    2008-01-01

    This paper summarizes CERN R&D work done in the framework of the European Commission's FP6 BioCare Project. The objective was to develop a novel "time-based" signal processing technique to read out LSO-APD photodetectors for medical imaging. An important aspect was to employ the technique in a combined scenario for both computer tomography (CT) and positron emission tomography (PET) with effectively no tradeoffs in efficiency and resolution compared to traditional single mode machines. This made the use of low noise and yet very high-speed monolithic front-end electronics essential so as to assure the required timing characteristics together with a high signal-to-noise ratio. Using APDs for photon detection, two chips, traditionally employed for particle physics, could be identified to meet the above criteria. Although both were not optimized for their intended new medical application, excellent performance in conjunction with LSO-APD sensors could be derived. Whereas a measured energy resolution of 16% (...

  19. Performance Analysis of OCDMA Based on AND Detection in FTTH Access Network Using PIN & APD Photodiodes

    Science.gov (United States)

    Aldouri, Muthana; Aljunid, S. A.; Ahmad, R. Badlishah; Fadhil, Hilal A.

    2011-06-01

    In order to comprise between PIN photo detector and avalanche photodiodes in a system used double weight (DW) code to be a performance of the optical spectrum CDMA in FTTH network with point-to-multi-point (P2MP) application. The performance of PIN against APD is compared through simulation by using opt system software version 7. In this paper we used two networks designed as follows one used PIN photo detector and the second using APD photo diode, both two system using with and without erbium doped fiber amplifier (EDFA). It is found that APD photo diode in this system is better than PIN photo detector for all simulation results. The conversion used a Mach-Zehnder interferometer (MZI) wavelength converter. Also we are study, the proposing a detection scheme known as AND subtraction detection technique implemented with fiber Bragg Grating (FBG) act as encoder and decoder. This FBG is used to encode and decode the spectral amplitude coding namely double weight (DW) code in Optical Code Division Multiple Access (OCDMA). The performances are characterized through bit error rate (BER) and bit rate (BR) also the received power at various bit rate.

  20. FACT-The first Cherenkov telescope using a G-APD camera for TeV gamma-ray astronomy

    International Nuclear Information System (INIS)

    Anderhub, H.; Backes, M.; Biland, A.; Boller, A.; Braun, I.; Bretz, T.; Commichau, S.; Commichau, V.; Domke, M.; Dorner, D.; Gendotti, A.; Grimm, O.; Gunten, H. von; Hildebrand, D.; Horisberger, U.; Koehne, J.-H.; Kraehenbuehl, T.; Kranich, D.; Krumm, B.; Lorenz, E.

    2011-01-01

    Geiger-mode Avalanche Photodiodes (G-APD) bear the potential to significantly improve the sensitivity of Imaging Air Cherenkov Telescopes (IACT). We are currently building the First G-APD Cherenkov Telescope (FACT) by refurbishing an old IACT with a mirror area of 9.5 square meters and are constructing a new, fine-pixelized camera using novel G-APDs. The main goal is to evaluate the performance of a complete system by observing very high energy gamma-rays from the Crab Nebula. This is an important field test to check the feasibility of G-APD-based cameras to replace at some time the PMT-based cameras of planned future IACTs like AGIS and CTA. In this article, we present the basic design of such a camera as well as some important details.

  1. Performing personnel dosimetry investigations and records quality assurance

    International Nuclear Information System (INIS)

    Perle, S.C.

    2002-01-01

    Radiation Safety Officers (RSOs) sometimes face situations in which personnel dosimetry estimates are required after dosimeters issued to radiation workers (film or TLD badges, extremity dosimeters, etc.) are lost or damaged before processing. This article was prepared to help those involved with personnel dosimetry investigations became aquatinted with this process. A factor that contributes to the anxiety of those unfamiliar with dosimetry investigations is the lack of published guidance available in this subject. More printed resources are needed to help radiation safety professionals familiarize themselves and understand personnel dosimetry investigations. Topics discussed in this presentation include the justification of performing dosimetry investigations, recommendations on how to perform them and the advantages of performing such investigations

  2. Epoxy encapsulant as serendipitous dosimeters during radiological/nuclear events

    Energy Technology Data Exchange (ETDEWEB)

    Barkyoumb, J.H. [Carderock Division, Naval Surface Warfare Center, 9500 MacArthur Blvd., West Bethesda, MD 20817-5700 (United States)], E-mail: jhbarky@earthlink.net; Mathur, V.K. [Carderock Division, Naval Surface Warfare Center, 9500 MacArthur Blvd., West Bethesda, MD 20817-5700 (United States)

    2008-02-15

    The radiation response of a smart chip (embedded integrated circuit) module has been reported earlier using the technique of optically stimulated luminescence (OSL). It was found that a smart chip module could be used to evaluate the personnel exposure in the accident dosimetry range. Through subsequent experiments, the radiation sensitivity of the chip module was traced to the epoxy encapsulant provided to protect the chip from the environment and physical damage and that the radiation sensitivity of the epoxy is due to the silica used as the 'filler' for controlling the thixotropic properties of the epoxy used for 'glob top' or 'dam-and-fill' encapsulation. It is desirable to retain the ability to use the smart chip as an accident dosimeter without requiring a modification of standard manufacturing process for which an infrastructure already exists to avoid additional costs. For this reason, we have investigated commercially available filled and unfilled epoxies both as received from the manufacturer and compared their response with epoxies to which commercial fillers are added. In this work we investigate the OSL response of various epoxies commonly used for potting of electronic circuits with and without various filler materials for their potential to be used as a casualty dosimeter in the exposure range of 0.5-10 Gy.

  3. Analysis of personnel monitoring control card data

    International Nuclear Information System (INIS)

    Ande, C.D.; Sneha, C.; Madhumita, B.; Bakshi, A.K.; Datta, D.

    2018-01-01

    In India, personnel monitoring of radiation workers for X-, beta- and gamma- radiation is carried out using a thermoluminescence dosemeter (TLD) system based on CaSO 4 :Dy Teflon TLD disc. A large number of radiation workers get very low occupational doses and their doses are reported as zero since it is not above detectable limits. Therefore, the detection of low levels of occupational dose over and above the natural background assumes great importance. In the present system, the estimation of the background dose is achieved by use of control dosemeters. An analysis of the readings of the control dosimeters sent to various institutions was carried out to arrive at conclusions regarding the validity of the use of control dosimeter

  4. Development of a TL personal dosimeter identifiable PA exposure, and comparison with commercial TL dosimeters

    International Nuclear Information System (INIS)

    Kwon, J.W.; Kim, H.K.; Lee, J.K.; Kim, J.L.

    2004-01-01

    A single-dosimeter worn on the anterior surface of the body of a worker was found to significantly underestimate the effective dose to the worker when the radiation comes from the back. Several researchers suggested that this sort of underestimation can be corrected to a certain extent by using an extra dosimeter on the back. However, use of multiple dosimeters also has disadvantages such as complication in control or incurrence of extra cost. Instead of the common multi-dosimeter approach, in this study, a single dosimeter introducing asymmetric filters which enabled to identify PA exposure was designed, and its dose evaluation algorithm for AP-PA mixed radiation fields was established. A prototype TL personal dosimeter was designed and constructed. The Monte Carlo simulations were utilized in the design process and verified by experiments. The dosimeter and algorithm were applicable to photon radiation having an effective energy beyond 100 keV in AP-PA mixed radiation fields. A simplified performance test based on ANSI N13.11 showed satisfactory results. Considering that the requirements of the International Electrotechnical Commission (IEC) and the American National Standards Institute (ANSI) with regard to the dosimeter on angular dependency is reinforced, the dosimeter and the dose evaluation algorithm developed in this study provides a useful approach in practical personal dosimetry against inhomogeneous high energy radiation fields. (author)

  5. Personnel radiation monitoring by thermoluminescence dosimetry (1995-96)

    International Nuclear Information System (INIS)

    Daw Mi Cho Cho; Daw Yi Yi Khin; Daw San San; U Maung Maung Tin; Daw Hla Hla Win

    2001-01-01

    Personnel radiation monitoring which is the dose assessment of individual doses from external radiation received by radiation workers has been carried out by Thermoluminescence Dosimetry system consisting of a Vinten Toledo TLD reader, LiF dosimeters and associated equipment. The exposed TLD dosimeters were measured by TLD reader and the dose evaluation and dose registration were done on personal computer. Due to the records of 1995-96, most of the radiation workers complied with the permissible dose recommended by IAEA and ICRP 60. (author)

  6. Miniature Active Space Radiation Dosimeter, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Space Micro will extend our Phase I R&D to develop a family of miniature, active space radiation dosimeters/particle counters, with a focus on biological/manned...

  7. Intercomparison measurements with albedo neutron dosimeters

    International Nuclear Information System (INIS)

    Alberts, W.G.; Kluge, H.

    1994-01-01

    Since the introduction of the albedo dosimeter as the official personal neutron dosimeter the dosimetry services concerned have participated in intercomparison measurements at the PTB. Their albedo dosimeters were irradiated in reference fields produced by unmoderated and D 2 O-moderated 252 Cf neutron sources in the standard irradiation facility of the PTB. Six fields with fluences different in energy and angle distribution could be realised in order to determine the response of the albedo dosimeter. The dose equivalent values evaluated by the services were compared with the reference values of the PTB for the directional dose equivalent H'(10). The results turned out to be essentially dependent on the evaluation method and the choice of the calibration factors. (orig.) [de

  8. The shelf life of dyed polymethylmethacrylate dosimeters

    International Nuclear Information System (INIS)

    Bett, R.; Watts, M.F.; Plested, M.E.

    2002-01-01

    The long-term stability of the radiation response of Harwell Red 4034 and Amber 3042 Perspex Dosimeters has been monitored for more than 15 years, and the resulting data used in the justification of their shelf-life specifications

  9. An improved dosimeter having constant flow pump

    International Nuclear Information System (INIS)

    Baker, W.B.

    1980-01-01

    A dosemeter designed for individual use which can be used to monitor toxic radon gas and toxic related products of radon gas in mines and which incorporates a constant air stream flowing through the dosimeter is described. (U.K.)

  10. Use of wrist albedo neutron dosimeters

    International Nuclear Information System (INIS)

    Hankins, D.E.

    1983-01-01

    We are developing a wrist dosimeter that can be used to measure the exposure at the wrist to x-rays, gamma rays, beta-particles, thermal neutrons and fast neutrons. It consists of a modified Hankins Type albedo neutron dosimeter and also contains three pieces of CR-39 plastic. ABS plastic in the form of an elongated hemisphere provides the beta and low energy x-ray shielding necessary to meet the requirement of depth dose measurements at 1 cm. The dosimeter has a beta window located in the side of the hemisphere oriented towards an object being held in the hands. A TLD 600 is positioned under the 1 cm thick ABS plastic and is used to measure the thermal neutron dose. At present we are using Velcro straps to hold the dosimeter on the inside of the wrist. 9 figures

  11. Floating Gate CMOS Dosimeter With Frequency Output

    Science.gov (United States)

    Garcia-Moreno, E.; Isern, E.; Roca, M.; Picos, R.; Font, J.; Cesari, J.; Pineda, A.

    2012-04-01

    This paper presents a gamma radiation dosimeter based on a floating gate sensor. The sensor is coupled with a signal processing circuitry, which furnishes a square wave output signal, the frequency of which depends on the total dose. Like any other floating gate dosimeter, it exhibits zero bias operation and reprogramming capabilities. The dosimeter has been designed in a standard 0.6 m CMOS technology. The whole dosimeter occupies a silicon area of 450 m250 m. The initial sensitivity to a radiation dose is Hz/rad, and to temperature and supply voltage is kHz/°C and 0.067 kHz/mV, respectively. The lowest detectable dose is less than 1 rad.

  12. Perfection of the individual photographic emulsion dosimeter

    International Nuclear Information System (INIS)

    Soudain, G.

    1960-01-01

    A photographic dosimeter making possible the measurement of γ radiation doses of from 10 mr up to 800 r by means of 3 emulsion bands of varying sensitivity stuck to the same support is described. The dosimeter has also a zone for marking and a test film insensitive to radiation. This requires a photometric measurement by diffuse reflection an d makes it possible to measure doses with an accuracy of 20 per cent. (author) [fr

  13. Operational aspects of the direct ion storage dosimeter system: 18 months of experience at CERN

    International Nuclear Information System (INIS)

    Carbonez, P.; Kotamaki, E.; Otto, Th.

    2006-01-01

    CERN, the European Organization for Nuclear Research, operates a dosimetry service for external exposure. The service monitors approximately 5000 Staff, scientific visitors and contractors personnel working on the organizations sites with personal dosimeters for personal dose equivalent (Hp(10), Hp(0.07)) from gamma, beta and neutron radiation. The dosimetry service is approved by the Swiss Federal Health Office, the competent authority for radiation protection. In 2004, the R.A.D.O.S. D.I.S. -1 dosemeter has been introduced to CERN as a gamma-beta dosemeter. Technical characteristics of this dosimeter, based on the direct ion storage technology, are high sensitivity, excellent linearity of the personal dose response with respect to radiation energy or dose, and long-term physical storage of personal dose-related information without the risk of fading. One important technical feature of the dosemeter is its 'instant reading' capability: the user himself can evaluate the received personal dose nondestructively on specific reader stations. This information is digitized, centralized by the CERN-wide network and stored in a database. The consequence of the 'instant reading' capability is a break with in the traditional organisation of a dosimetry service. The personal dosimeters are no longer exchanged periodically for evaluation, but a monthly value of personal dose is calculated from the readings initiated by the user. After a wearing period of one year, users are invited to exchange the dosimeter against a new, recently calibrated unit. The introduction of the D.I.S.-1 dosimeter has profoundly changed the type of work in CERN dosimetry service. Technical and laboratory work (development of film dosimeters, densitometric evaluation) have made place for computer-based procedures and database management. (authors)

  14. A fibre optic dosimeter customised for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Suchowerska, N. [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, NSW 2050 (Australia); School of Physics, University of Sydney, NSW 2006 (Australia)], E-mail: Natalka@email.cs.nsw.gov.au; Lambert, J.; Nakano, T. [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, NSW 2050 (Australia); School of Physics, University of Sydney, NSW 2006 (Australia); Law, S. [School of Physics, University of Sydney, NSW 2006 (Australia); Optical Fibre Technology Centre, University of Sydney, 206 National Innovation Centre, Australian Technology Park, Eveleigh, NSW 1430 (Australia); Elsey, J. [Bandwidth Foundry Pty Ltd, Australian Technology Park, NSW, 1430 (Australia); McKenzie, D.R. [School of Physics, University of Sydney, NSW 2006 (Australia)

    2007-04-15

    In-vivo dosimetry for brachytherapy cancer treatment requires a small dosimeter with a real time readout capability that can be inserted into the patient to determine the dose to critical organs. Fibre optic scintillation dosimeters, consisting of a plastic scintillator coupled to an optical fibre, are a promising dosimeter for this application. We have implemented specific design features to optimise the performance of the dosimeter for specific in-vivo dosimetry during brachytherapy. Two sizes of the BrachyFOD{sup TM} scintillation dosimeter have been developed, with external diameters of approximately 2 and 1 mm. We have determined their important dosimetric characteristics (depth dose relation, angular dependence, energy dependence). We have shown that the background signal created by Cerenkov and fibre fluorescence does not significantly affect the performance in most clinical geometries. The dosimeter design enables readout at less than 0.5 s intervals. The clinical demands of real time in-vivo brachytherapy dosimetry can uniquely be satisfied by the BrachyFOD{sup TM}.

  15. Polymer gel dosimeter based on itaconic acid

    International Nuclear Information System (INIS)

    Mattea, Facundo; Chacón, David

    2015-01-01

    A new polymeric dosimeter based on itaconic acid and N, N’-methylenebisacrylamide was studied. The preparation method, compositions of monomer and crosslinking agent and the presence of oxygen in the dosimetric system were analyzed. The resulting materials were irradiated with an X-ray tube at 158 cGy/min, 226 cGy min and 298 cGy/min with doses up to 1000 Gy. The dosimeters presented a linear response in the dose range 75–1000 Gy, sensitivities of 0.037 1/Gy at 298 cGy/min and an increase in the sensitivity with lower dose rates. One of the most relevant outcomes in this study was obtaining different monomer to crosslinker inclusion in the formed gel for the dosimeters where oxygen was purged during the preparation method. This effect has not been reported in other typical dosimeters and could be attributed to the large differences in the reactivity among these species. - Highlights: • A novel polymer gel dosimeters based on itaconic acid is presented and characterized. • The typical linear trend of the dose behavior in a specific dose range was found. • Different gel structures were formed when oxygen and an antioxidant were present. • Absorbed dose is univocally correlated with optic absorbance and Raman spectroscopy. • Itaconic acid appears as a reliable radiation dosimeter that may be further improved.

  16. Comparative study of some new EPR dosimeters

    International Nuclear Information System (INIS)

    Alzimami, K.S.; Maghraby, Ahmed M.; Bradley, D.A.

    2014-01-01

    Investigations have been made of four new radiation dosimetry EPR candidates from the same family of materials: sulfamic acid, sulfanillic acid, homotaurine, and taurine. Mass energy attenuation coefficients, mass stopping power values and the time dependence of the radiation induced radicals are compared. Also investigated are the microwave saturation behavior and the effect of applied modulation amplitude on both peak-to-peak line width (W PP ) and peak-to-peak signal height (H PP ). The dosimeters are characterized by simple spectra and stable radiation-induced radicals over reasonable durations, especially in taurine dosimeters. Sulfamic acid dosimeters possessed the highest sensitivity followed by taurine and homotaurine and sulfanillic. - Highlights: ► Several EPR dosimeters were suggested based on SO 3 − radical. ► Taurine, homotaurine, sulfanilic, and sulfamic acid all possess simple EPR spectra. ► Dosimeters were compared to each other in terms of the dosimetric point of view. ► Energy dependence curves of the selected dosimeters were compared to eachother

  17. Application of solid dosimeter to radiation control

    International Nuclear Information System (INIS)

    Tsujimoto, Tadashi

    1988-01-01

    Individual exposure dose measuring devices are used to measure the dose of each person in facilities using radiations. Major devices of this type currently used in Japan include the film badge, thermoluminescence dosimeter, portable radiation dosimeter and fluorescent glass dosimeter. All of these devices except the portable radiation dosimeter are of a solid type. Various portable-type spatial dose rate measuring devices, generally called survey meters, are available to determine the spatial distribution of radiations. Major survey meters incorporates an ionization chamber, GM counter tube or scintillation counter, while BF 3 counting tubes are available for neutron measurement. Of these, the scintillation dosimeter is of a solid type. A new scintillation survey meter has recently been developed which incorporated a discrimination bias modulation circuit. Dosimeters incorporating an ionization chamber or a GM counter tube are generally used as portable alarms. Recently, a new solid-type alarm has been developed which incorporates a solicon radiation detector. Microcomputers are also used for self-diagnosis, data processing, automatic calibration, etc. (Nogami, K.)

  18. DNA adducts as molecular dosimeters

    International Nuclear Information System (INIS)

    Lucier, G.W.

    1990-01-01

    There is compelling evidence that DNA adducts play an important role in the actions of many pulmonary carcinogens. During the last ten years sensitive methods (antibodies and 32 P-postlabeling) have been developed that permit detection of DNA adducts in tissues of animals or humans exposed to low levels of some genotoxic carcinogens. This capability has led to approaches designed to more reliably estimate the shape of the dose-response curve in the low dose region for a few carcinogens. Moreover, dosimetry comparisions can, in some cases, be made between animals and humans which help in judging the adequacy of animal models for human risk assessments. There are several points that need to be considered in the evaluation of DNA adducts as a molecular dosimeter. For example, DNA adduct formation is only one of many events that are needed for tumor development and some potent carcinogens do not form DNA adducts; i.e., TCDD. Other issues that need to be considered are DNA adduct heterogeneity, DNA repair, relationship of DNA adducts to somatic mutation and cell specificity in DNA adduct formation and persistence. Molecular epidemiology studies often require quantitation of adducts in cells such as lymphocytes which may or may not be reliable surrogates for adduct concentrations in target issues. In summary, accurate quantitation of low levels of DNA adducts may provide data useful in species to species extrapolation of risk including the development of more meaningful human monitoring programs

  19. A Highly Sensitive Multi-Element HgCdTe E-APD Detector for IPDA Lidar Applications

    Science.gov (United States)

    Beck, Jeff; Welch, Terry; Mitra, Pradip; Reiff, Kirk; Sun, Xiaoli; Abshire, James

    2014-01-01

    An HgCdTe electron avalanche photodiode (e-APD) detector has been developed for lidar receivers, one application of which is integrated path differential absorption lidar measurements of such atmospheric trace gases as CO2 and CH4. The HgCdTe APD has a wide, visible to mid-wave-infrared, spectral response, high dynamic range, substantially improved sensitivity, and an expected improvement in operational lifetime. A demonstration sensor-chip assembly consisting of a 4.3 lm cutoff HgCdTe 4 9 4 APD detector array with 80 micrometer pitch pixels and a custom complementary metal-oxide-semiconductor readout integrated circuit was developed. For one typical array the APD gain was 654 at 12 V with corresponding gain normalized dark currents ranging from 1.2 fA to 3.2 fA. The 4 9 4 detector system was characterized at 77 K with a 1.55 micrometer wavelength, 1 microsecond wide, laser pulse. The measured unit gain detector photon conversion efficiency was 91.1%. At 11 V bias the mean measured APD gain at 77 K was 307.8 with sigma/mean uniformity of 1.23%. The average, noise-bandwidth normalized, system noise-equivalent power (NEP) was 1.04 fW/Hz(exp 1/2) with a sigma/mean of 3.8%. The measured, electronics-limited, bandwidth of 6.8 MHz was more than adequate for 1 microsecond pulse detection. The system had an NEP (3 MHz) of 0.4 fW/Hz(exp 1/2) at 12 V APD bias and a linear dynamic range close to 1000. A gain-independent quantum-limited SNR of 80% of full theoretical was indicative of a gain-independent excess noise factor very close to 1.0 and the expected APD mode quantum efficiency.

  20. Composite Resin Dosimeters: A New Concept and Design for a Fibrous Color Dosimeter.

    Science.gov (United States)

    Kinashi, Kenji; Iwata, Takato; Tsuchida, Hayato; Sakai, Wataru; Tsutsumi, Naoto

    2018-04-11

    Polystyrene (PS)-based composite microfibers combined with a photochromic spiropyran dye, 1,3,3-trimethylindolino-6'-nitrobenzopyrylospiran (6-nitro BIPS), and a photostimulable phosphor, europium-doped barium fluorochloride (BaFCl:Eu 2+ ), were developed for the detection of X-ray exposure doses on the order of approximately 1 Gy. To produce the PS-based composite microfibers, we employed a forcespinning method that embeds a high concentration of phosphor in PS in a safe, inexpensive, and simple procedure. On the basis of the optimization of the forcespinning process, fibrous color dosimeters with a high radiation dose sensitivity of 1.2-4.4 Gy were fabricated. The color of the dosimeters was found to transition from white to blue in response to X-ray exposure. The optimized fibrous color dosimeter, made from a solution having a PS/6-nitro BIPS/BaFCl:Eu 2+ /C 2 Cl 4 ratio of 7.0/0.21/28.0/28.0 (wt %) and produced with a 290 mm distance between the needle and collectors, a 0.34 mm 23 G needle nozzle, and a spinneret rotational rate of 3000 rpm, exhibited sensitivity to a dose as low as 1.2 Gy. To realize practical applications, we manufactured the optimized fibrous color dosimeter into a clothlike color dosimeter. The clothlike color dosimeter was mounted on a stuffed bear, and its coloring behavior was demonstrated upon X-ray exposure. After exposure with X-ray, a blue colored and shaped in the form of the letter "[Formula: see text]" clearly appeared on the surface of the clothlike color dosimeter. The proposed fibrous color dosimeters having excellent workability will be an unprecedented dosimetry and contributed to all industries utilizing radiation dosimeters. This new fibrous "composite resin dosimeter" should be able to replace traditional, wearable, and individual radiation dose monitoring devices, such as film badges.

  1. Time over threshold based multi-channel LuAG-APD PET detector

    International Nuclear Information System (INIS)

    Shimazoe, Kenji; Orita, Tadashi; Nakamura, Yasuaki; Takahashi, Hiroyuki

    2013-01-01

    To achieve efficient signal processing, several time-based positron emission tomography (PET) systems using a large number of granulated gamma-ray detectors have recently been proposed. In this work described here, a 144-channel Pr:LuAG avalanche photodiode (APD) PET detector that uses time over threshold (ToT) and pulse train methods was designed and fabricated. The detector is composed of 12×12 Pr:LuAG crystals, each of which produces a 2 mm×2 mm×10 mm pixel individually coupled to a 12×12 APD array, which in turn is connected pixel-by-pixel with one channel of a time over threshold based application-specific integrated circuit (ToT-ASIC) that was designed and fabricated using a 0.25 μm 3.3 V Taiwan Semiconductor Company complementary metal oxide semiconductor (TSMC CMOS) process. The ToT outputs are connected through a field-programmable gate array (FPGA) to a data acquisition (DAQ) system. Three front-end ASIC boards—each incorporating a ToT-ASIC chip, threshold control digital-to-analog converters (DACs), and connectors, and dissipating power at about 230 mW per board—are used to read from the 144-channel LuAG-APD detector. All three boards are connected through an FPGA board that is programmed to calibrate the individual thresholds of the ToT circuits to allow digital multiplexing to form an integrated PET module with a measured timing resolution of 4.2 ns. Images transmitted by this PET system can be successfully acquired through collimation masks. As a further implementation of this technology, an animal PET system consisting of eight gamma pixel modules forming a ring is planned

  2. Blood proteins as carcinogen dosimeters

    International Nuclear Information System (INIS)

    Tannenbaum, S.R.; Skipper, P.L.

    1986-01-01

    The problem of quantifying exposure to genotoxins in a given individual represents a formidable challenge. In this paper methods which rely on the covalent binding of carcinogens and their metabolites to blood proteins are described. That carcinogens interact with proteins as well as with DNA has been established, although whether protein-carcinogen adducts can result in genetic damage has not been established. It has been shown, however, that the amount of a protein carcinogen adduct formed may be used as a quantitative measure of exposure to a carcinogen. Such a measure presumably is reflective of the absorption, metabolism, and excretion of the compound in an exposed individual. Protein adduction may reflect exposure in a time-frame of weeks to months. Thus, protein adduct measurement is a form of human chemical dosimetry. Hemoglobin and albumin are promising candidates for such dosimeters. Hemoglobin has a lifetime of about 120 days in humans; thus, circulating levels of carcinogen-modified hemoglobin will reflect the level of carcinogen exposure during a period of nearly four months. It also possesses some metabolic competence, particularly, the ability to oxidize aromatic hydroxylamines to nitroso compounds which react quite efficiently with sulfhydryl groups. Albumin has a half-life of 20 to 25 days in man. This protein does not possess metabolic capacity other than, perhaps, some esterase activity. In contrast to hemoglobin, though, it is not protected by the erythrocyte membrane and might be the target for a greater number of carcinogens. It is present and is synthesized in the same cells in which the reactive metabolic intermediates of carcinogens are mostly formed - the hepatocytes. Also, albumin has a number of high-affinity binding sites for a broad spectrum of xenobiotics and endobiotics. 25 refs., 1 tab

  3. Personnel-dosimetry intercomparison studies at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

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

    1982-01-01

    Since 1974, seven annual personnel dosimetry intercomparison studies have been conducted at the Oak Ridge National Laboratory using the Health Physics Reactor. These studies have produced more than 2000 measurements by 72 participating organizations of neutron and gamma dose equivalents between 0.1 to 15.0 mSv in six mixed radiation fields. The relative performance of three basic types of personnel neutron dosimeters (nuclear emulsion film, thermoluminescent, and track-etch) and two basic types of gamma dosimeters (film and thermoluminescent) was assessed based on experimental results obtained during the seven intercomparisons

  4. Quality assurance of the manual OSLD Badge based personnel monitoring system

    International Nuclear Information System (INIS)

    Kumar, Munish; Gaonkar, U.P.; Koul, D.K.; Datta, D.; Singh, S.K.; Rakesh, R.B.; Kulkarni, M.S.; Ratna, P.

    2018-01-01

    Optically stimulated luminescence (OSL) based technique is widely used for monitoring of radiation workers exposed to x, gamma and beta radiations. Features such as multiple readout, short processing time, better beta response, absence of infra red signal (no heating), flexibility in the dosimeter design using binders or substrates having low melting point are associated advantages. Presently α-Al 2 O 3 :C and BeO based dosimeters are popularly used for personnel monitoring applications worldwide. The present paper describe results of the external quality control check (QAC) tests performed for the present OSLD badge based personnel monitoring system. The results were analyzed as per ANSI criteria and Trumpet curve methods

  5. Personnel Neutron Monitoring at AB Atomenergi

    Energy Technology Data Exchange (ETDEWEB)

    Hagsgaard, S; Widell, C O

    1964-02-15

    The routine personnel monitoring of fast neutrons is carried out by the counting of tracks in a nuclear emulsion. The tracks are counted in a microscope on a projection screen. This is a very tedious job and is only done on irradiated films which are counted over 6 mm{sup 2}. The irradiated films are selected according to the recorded dose on the gamma film. It is often difficult to tell how much the visible tracks have faded during a two-weeks period. Fortunately the fading does not often exceed 20 % for this period. If the dosimeter has been gamma-irradiated, it may be difficult to recognize the proton tracks. If the film is stored for some time before being developed, this gamma fog will to some extent fade away. For large neutron doses a foil activation dosimeter is used. This dosimeter consists of a cadmium-shielded phosphorus foil, a cadmium shielded gold foil and an unshielded gold foil. The phosphorus foil has to be counted shortly after exposure.

  6. Personnel Neutron Monitoring at AB Atomenergi

    International Nuclear Information System (INIS)

    Hagsgaard, S.; Widell, C.O.

    1964-02-01

    The routine personnel monitoring of fast neutrons is carried out by the counting of tracks in a nuclear emulsion. The tracks are counted in a microscope on a projection screen. This is a very tedious job and is only done on irradiated films which are counted over 6 mm 2 . The irradiated films are selected according to the recorded dose on the gamma film. It is often difficult to tell how much the visible tracks have faded during a two-weeks period. Fortunately the fading does not often exceed 20 % for this period. If the dosimeter has been gamma-irradiated, it may be difficult to recognize the proton tracks. If the film is stored for some time before being developed, this gamma fog will to some extent fade away. For large neutron doses a foil activation dosimeter is used. This dosimeter consists of a cadmium-shielded phosphorus foil, a cadmium shielded gold foil and an unshielded gold foil. The phosphorus foil has to be counted shortly after exposure

  7. Time-dependent, low-dose reporting limit for dosimeters that are taken home at the end of the workday

    International Nuclear Information System (INIS)

    Sonder, E.

    1994-01-01

    In routine personnel dosimetry, it is usual to report doses only where th occupational dose (measured dose with background subtracted) is greater than previously determined reporting limit. The reporting limit, although se administratively, should be justified by an assessment of the errors inherent in th personnel and background dose measurements, and estimates of the probability that a zero exposure will yield a dosimeter response equal to the reporting limit. For background subtraction and reporting limits, it was realized that the source of low-dose uncertainty is very much dependent on whether dosimeters are held in racks at the work site or remain with the employee. The External dosimetry Program for the DOE facilities at Oak Ridge, Tennessee, is operated such that dosimeters are taken home by the employee at the end of each workday. This report is a summary measurements of background radiation in a variety of home locations, and calculations of the effect of the variation of this background on the uncertainty low-level occupational dose and on the reporting level. When dosimeters are stored at a given location (e.g., the facility gate), it theoretically possible to determine the background there to any desired accuracy; the errors in occupational dose are then those due to measurement noise and dosimeter calibration. However, when different dosimeters are stored in different homes, th difference in background between a particular location and the average for a locations appears as an added uncertainty in the occupational dose. Since this difference is not random, but fixed for a given location, the error due to this difference increases linearly with assignment time. From the background measurements, time-dependent values of the standard deviation of occupational do and critical levels are derived and used to define an expression for the reporting limit

  8. Automated Calibration of Dosimeters for Diagnostic Radiology

    International Nuclear Information System (INIS)

    Romero Acosta, A.; Gutierrez Lores, S.

    2015-01-01

    Calibration of dosimeters for diagnostic radiology includes current and charge measurements, which are often repetitive. However, these measurements are usually done using modern electrometers, which are equipped with an RS-232 interface that enables instrument control from a computer. This paper presents an automated system aimed to the measurements for the calibration of dosimeters used in diagnostic radiology. A software application was developed, in order to achieve the acquisition of the electric charge readings, measured values of the monitor chamber, calculation of the calibration coefficient and issue of a calibration certificate. A primary data record file is filled and stored in the computer hard disk. The calibration method used was calibration by substitution. With this system, a better control over the calibration process is achieved and the need for human intervention is reduced. the automated system will be used in the calibration of dosimeters for diagnostic radiology at the Cuban Secondary Standard Dosimetry Laboratory of the Center for Radiation Protection and Hygiene. (Author)

  9. Water equivalence of polymer gel dosimeters

    International Nuclear Information System (INIS)

    Sellakumar, P.; James Jebaseelan Samuel, E.; Supe, Sanjay S.

    2007-01-01

    To evaluate the water equivalence and radiation transport properties of polymer gel dosimeters over the wide range of photon and electron energies 14 different types of polymer gels were considered. Their water equivalence was evaluated in terms of effective atomic number (Z eff ), electron density (ρ e ), photon mass attenuation coefficient (μ/ρ), photon mass energy absorption coefficient (μ en /ρ) and total stopping power (S/ρ) tot of electrons using the XCOM and the ESTAR database. The study showed that the effective atomic number of polymer gels were very close ( en /ρ for all polymer gels were in close agreement ( tot of electrons in polymer gel dosimeters were within 1% agreement with that of water. From the study we conclude that at lower energy (<80keV) the polymer gel dosimeters cannot be considered water equivalent and study has to be carried out before using the polymer gel for clinical application

  10. HgCdTe APD-based linear-mode photon counting components and ladar receivers

    Science.gov (United States)

    Jack, Michael; Wehner, Justin; Edwards, John; Chapman, George; Hall, Donald N. B.; Jacobson, Shane M.

    2011-05-01

    Linear mode photon counting (LMPC) provides significant advantages in comparison with Geiger Mode (GM) Photon Counting including absence of after-pulsing, nanosecond pulse to pulse temporal resolution and robust operation in the present of high density obscurants or variable reflectivity objects. For this reason Raytheon has developed and previously reported on unique linear mode photon counting components and modules based on combining advanced APDs and advanced high gain circuits. By using HgCdTe APDs we enable Poisson number preserving photon counting. A metric of photon counting technology is dark count rate and detection probability. In this paper we report on a performance breakthrough resulting from improvement in design, process and readout operation enabling >10x reduction in dark counts rate to ~10,000 cps and >104x reduction in surface dark current enabling long 10 ms integration times. Our analysis of key dark current contributors suggest that substantial further reduction in DCR to ~ 1/sec or less can be achieved by optimizing wavelength, operating voltage and temperature.

  11. Fiber-optic dosimeters for radiation therapy

    Science.gov (United States)

    Li, Enbang; Archer, James

    2017-10-01

    According to the figures provided by the World Health Organization, cancer is a leading cause of death worldwide, accounting for 8.8 million deaths in 2015. Radiation therapy, which uses x-rays to destroy or injure cancer cells, has become one of the most important modalities to treat the primary cancer or advanced cancer. The newly developed microbeam radiation therapy (MRT), which uses highly collimated, quasi-parallel arrays of x-ray microbeams (typically 50 μm wide and separated by 400 μm) produced by synchrotron sources, represents a new paradigm in radiotherapy and has shown great promise in pre-clinical studies on different animal models. Measurements of the absorbed dose distribution of microbeams are vitally important for clinical acceptance of MRT and for developing quality assurance systems for MRT, hence are a challenging and important task for radiation dosimetry. On the other hand, during the traditional LINAC based radiotherapy and breast cancer brachytherapy, skin dose measurements and treatment planning also require a high spatial resolution, tissue equivalent, on-line dosimeter that is both economical and highly reliable. Such a dosimeter currently does not exist and remains a challenge in the development of radiation dosimetry. High resolution, water equivalent, optical and passive x-ray dosimeters have been developed and constructed by using plastic scintillators and optical fibers. The dosimeters have peak edge-on spatial resolutions ranging from 50 to 500 microns in one dimension, with a 10 micron resolution dosimeter under development. The developed fiber-optic dosimeters have been test with both LINAC and synchrotron x-ray beams. This work demonstrates that water-equivalent and high spatial resolution radiation detection can be achieved with scintillators and optical fiber systems. Among other advantages, the developed fiber-optic probes are also passive, energy independent, and radiation hard.

  12. Diffusion measurement in ferrous infused gel dosimeters

    International Nuclear Information System (INIS)

    Zahmatkesh, M. H.; Healy, B. J.

    2003-01-01

    Background: The compositions of Ferrous sulphate, Agarose and Xylenol orange dye and Ferrous sulphate, Gelatin and Xylenol orange dye in solution of distilled water and sulphuric acid are two tissue-equivalent gel dosimeters. Ionizing radiation causes oxidation of Fe 2+ ion to Fe 3+ ions which diffuse through the gel matrix and blur the image of absorbed dose over a period of hours after irradiation. Materials and methods: 25 m M sulphuric acid, 0.4 mm ferrous ammonium sulphate, 0.2 mm xylenol orange dye and 1% by weight agarose in distilled water named Agarose and Xylenol orange dye and 0.1 mm ferrous ammonium sulphate, 0.1 mm xylenol orange dye, 50 mm sulphuric acid and 5% by weight gelatin in distilled water named Gelatin and Xylenol orange dye are used as two gel dosimeters. All chemicals were supplied by Sigma Ald ridge Company, Germany. The gels were poured in Perspex casts and were irradiated to a beam of X ray from linear accelerators or X ray machine. Results: In this study diffusion coefficients of Agarose and Xylenol orange dye and Gelatin and Xylenol orange dye dosimeters have been measured through a computer program for different temperature. The ferric ion diffusion coefficient (D) for the Agarose and Xylenol orange dye and Gelatin and Xylenol orange dye dosimeters were measured as (1.19.±0.03) x 10 -2 cm 2 .hr -1 and (0.83±0.03) x 10 -2 cm 2 .hr -1 respectively at room temperature. Conclusion: For both dosimeters the diffusion coefficients decreased with gel storage temperatures down to 6 d ig C . Gelatin and Xylenol orange dye dosimeters have advantage of lower diffusion coefficient for a specified temperature

  13. DEPRON dosimeter for ``Lomonosov'' satellite

    Science.gov (United States)

    Brilkov, Ivan; Vedenkin, Nikolay; Panasyuk, Mikhail; Amelyushkin, Aleksandr; Petrov, Vasily; Nechayev, Oleg; Benghin, Victor

    appearance of the instrument DEPRON (Dosimeter of Electrons, PROtons and Neutrons) was determined. DEPRON is intended for registration of the absorbed doses and linear energy transfer spectra for high-energy electrons, protons and nuclei of space radiation, as well as registration of thermal and slow neutrons. The experiment based on DEPRON instrument is aimed at the studies of the distribution of space radiation dose rate at high latitude paths in order to study the flight paths of perspective manned spacecraft. Present work provides a brief description of the DEPRON instrument, its calibration results and the structure of the output data.

  14. Research on the formula of radiochromic film dosimeters

    International Nuclear Information System (INIS)

    Li Huazhi; Xiao Zhenhong; Lin Min; Cui Ying; Chen Kesheng; Chen Yundong; Ye Hongsheng; Lin Jingwen

    2006-10-01

    The formula of radiochromic film dosimeters was studied. Commercially available nylon was used as the matrix, while hexahydroxyethyl pararosaniline cyanide (HPR-CN) and pararosaniline cyanide (PR-CN) that are made in China and other countries were used as the dyes of the dosimeters. the performance of the thin film dosimeters made in CIAE was tested and compared with each other. The formula of the dosimeters was finally confirmed by testing its physical properties and dosimetric characteristics. (authors)

  15. Current 2-μm dial measurements of atmospheric CO2 and expected results from space using new MCT APDS

    Science.gov (United States)

    Dumas, A.; Gibert, F.; Rothman, J.; Édouart, D.; Le Mounier, F.; Cénac, C.

    2017-11-01

    In the framework of CO2 monitoring in the Atmospheric Boundary Layer (ABL), a ground-based 2-μm Differential Absorption Lidar (DIAL) has been developed at the Laboratoire de Météorologie Dynamique (LMD) in Palaiseau. In order to derive flux information, this system has been set up with coherent detection, which allows to combine CO2 density measurements with wind velocity measurements. On the other hand, new advances in the field of Mercury Cadmium Tellure (MCT) Avalanche Photodiodes (APDs) open the way for high-precision measurements in direct detection ultimately from space. In this study, we first report on state of the art measurements obtained with the current coherent DIAL system before presenting expected results for a similar laser transmitter equipped with MCT APDs. For this latter part, we use a numerical model which relies on APDs performance data provided by the Laboratoire d'Électronique et de Technologie de l'Information (LETI).

  16. Experimental ratio between the 'real' dose per organ and the calculated dose determined by means of the Embalse nuclear power plant's personal dosimeter

    International Nuclear Information System (INIS)

    Thomasz, E.; Salas, C.A.

    1987-01-01

    The specific purpose of the study was to determine the experimental ratio between the reading of dosimeters used by the personnel of the Embalse nuclear power plant and the 'real' dose absorbed by the worker in different organs. An anthropomorphic phantom ALDERSON internal and externally loaded with approximately 150 TLD crystals was used. This phantom was placed in five enclosures that were usually occupied by workers of the Embalse nuclear power plant. In this way, the average dose per organ and the effective equivalent dosis in each enclosure could be calculated and compared with the personal dosimeters placed over the thorax and the conversion factor rem/rem for each enclosure was determined. The average factor resulting from the five considered enclosures was 0.73 rem/rem. This means that the personal dosimeters over value the real dosis absorbed by the personnel of the Embalse nuclear power plant in approximately 37%. (Author)

  17. Indoor radon level measurements in Iran using AEOI passive dosimeters

    International Nuclear Information System (INIS)

    Sohrabi, M.; Solaymanian, A.R.

    1988-01-01

    A passive radon diffusion dosimeter was developed at the RPD of AEOI for nationwide indoor radon level measurements. Several parameters of the dosimeter were studied. Radon levels were determined in about 250 houses in Ramsar (a high natural radiation area), Tehran, Babolsar and Gonabad. In this paper, the results of some dosimeter parameters as well as radon levels in indoor air are reported

  18. Calibration and testing of the DMG gamma dosimeter

    International Nuclear Information System (INIS)

    Dolgirev, E.I.

    1987-01-01

    25-1000 nGy/h (2.5-1000 μrad/h) absorbed dose gamma dosimeter for measuring the efficient equivalent irradiation dose for population is developed. It has two subranges 1000 nGy/h and 250 nGy/h. Results of dosimeter calibration and testing are presented. The dosimeter error for both subranges is less than 10%

  19. Development and dosimetric evaluation of radiochromic PCDA vesicle gel dosimeters

    International Nuclear Information System (INIS)

    Sun, P.; Fu, Y.C.; Hu, J.; Hao, N.; Huang, W.; Jiang, B.

    2016-01-01

    The gel dosimeter has the unique capacity in recording radiation dose distribution in three dimensions (3D), which has the specific advantages in dosimetry measurements where steep dose gradients exist, such as in intensity-modulated radiation therapy (IMRT), brachytherapy and so on. Some 3D dosimeters, such as Fricke gel dosimeters, polymer gel dosimeters, the PRESAGE plastic dosimeters and micelle gel dosimeters have appeared recently. However, there are several disadvantages of these 3D dosimeters limit their application in radiotherapy dose verification. In this study, a novel radiochromic gel dosimeter for 3D dose verification of radiotherapy was developed by dispersing nanovesicles self-assembled by 10,12-pentacosadiynoic acid (PCDA) into the tissue equivalence gel matrix. The characteristics of radiochromic PCDA vesicle gel dosimeters were evaluated. The results indicate that these radiochromic gel dosimeters have good linear dose response to X-ray irradiation in the dose range of 2–100 Gy. In addition, the radiochromic gel dosimeters breakthrough the limitations of the existing gel dosimeters such as diffusion effect, post-radiation effect, and poor forming ability. The response of the gel dosimeter does not show any dose rate dependence, energy dependence and temperature effect, and there was no obvious difference in the gel response between single and cumulative dose of fractional irradiation. Hence, the radiochromic PCDA vesicle gel dosimeters developed in this study could be generally applied to 3D dose verification in radiotherapy. - Highlights: • A novel radiochromic gel dosimeter was developed by dispersing PCDA nanovesicles into the tissue equivalence gel matrix. • This nanovesicle overcomes the dose image blurring caused by the diffusion of monomer molecules. • This nanovesicle limits the polymer chain growth, so as to reduce the post-radiation effect. • The gel matrixes possess excellent tissue equivalence and elastic strength, which

  20. Investigating hydrogel dosimeter decomposition by chemical methods

    International Nuclear Information System (INIS)

    Jordan, Kevin

    2015-01-01

    The chemical oxidative decomposition of leucocrystal violet micelle hydrogel dosimeters was investigated using the reaction of ferrous ions with hydrogen peroxide or sodium bicarbonate with hydrogen peroxide. The second reaction is more effective at dye decomposition in gelatin hydrogels. Additional chemical analysis is required to determine the decomposition products

  1. Silicon Diode Dosimeter for Fast Neutrons

    International Nuclear Information System (INIS)

    Svansson, L.; Widell, C.O.; Swedberg, P.; Wik, M.

    1968-11-01

    The change of the current-voltage characteristics of a small silicon diode is used as a measure of fast neutron dose in the Fast Neutron Dosimeter 5422. This change is permanent and therefore it is possible to integrate doses over a long period of time. Doses from some rad up to 1000 rad can be measured and the information stored is not destroyed during readout. Considerable research work in this field has previously been carried out by the Swedish Institute for National Defence in collaboration with the Institute of Semiconductor Research Stockholm. The present investigation has been made in order to establish the possibilities of the dosimeter for practical applications and to study the variations of important parameters as a function of the production process. In particular the following parameters have been studied: - dose sensitivity, - energy dependence; - fading effect; - temperature influence; - maximum measurable dose. In general one might conclude that the dosimeter 5422 well fulfills requirements usually specified for a dosimeter for field service. Temperature influence and fading effect are of little practical importance within the recommended range of measurement

  2. Silicon Diode Dosimeter for Fast Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Svansson, L; Widell, C O; Swedberg, P [The Inst. of Semiconductor Researc h, Stockholm (Sweden); Wik, M [The Swedish Institute for National Defence, Sun dbyberg (Sweden)

    1968-11-15

    The change of the current-voltage characteristics of a small silicon diode is used as a measure of fast neutron dose in the Fast Neutron Dosimeter 5422. This change is permanent and therefore it is possible to integrate doses over a long period of time. Doses from some rad up to 1000 rad can be measured and the information stored is not destroyed during readout. Considerable research work in this field has previously been carried out by the Swedish Institute for National Defence in collaboration with the Institute of Semiconductor Research Stockholm. The present investigation has been made in order to establish the possibilities of the dosimeter for practical applications and to study the variations of important parameters as a function of the production process. In particular the following parameters have been studied: - dose sensitivity, - energy dependence; - fading effect; - temperature influence; - maximum measurable dose. In general one might conclude that the dosimeter 5422 well fulfills requirements usually specified for a dosimeter for field service. Temperature influence and fading effect are of little practical importance within the recommended range of measurement.

  3. Compton effect thermally activated depolarization dosimeter

    Science.gov (United States)

    Moran, Paul R.

    1978-01-01

    A dosimetry technique for high-energy gamma radiation or X-radiation employs the Compton effect in conjunction with radiation-induced thermally activated depolarization phenomena. A dielectric material is disposed between two electrodes which are electrically short circuited to produce a dosimeter which is then exposed to the gamma or X radiation. The gamma or X-radiation impinging on the dosimeter interacts with the dielectric material directly or with the metal composing the electrode to produce Compton electrons which are emitted preferentially in the direction in which the radiation was traveling. A portion of these electrons becomes trapped in the dielectric material, consequently inducing a stable electrical polarization in the dielectric material. Subsequent heating of the exposed dosimeter to the point of onset of ionic conductivity with the electrodes still shorted through an ammeter causes the dielectric material to depolarize, and the depolarization signal so emitted can be measured and is proportional to the dose of radiation received by the dosimeter.

  4. Clinical dosimeter based on diamond detector

    International Nuclear Information System (INIS)

    Chervjakov, A.M.; Ljalina, L.I.; Ljutina, G.J.; Khrunov, V.S.; Martynov, S.S.; Popov, S.A.

    2002-01-01

    Full text: Diamond detectors have found application in the relative dosimetry and their parameters have been described elsewhere. Today, the exclusive producer of the diamond detector is the Institute of Physical and Technical Problems, Russia, and exclusive dealer is the PTW-Freiburg. The main features of the diamond detector are good long time stability, suitable range of the energy dependence for photon and electron beams in clinical use, independence of the measured date from temperature and pressure. The high sensitivity per volume unit of the diamond detector (1500 times higher than ionization chamber) allowed using detectors with very small volume (1-5 mm 3 ) and rather simple electronics for ionization current registration. The new dosimeter consists of the diamond detector itself, 40 m registration cable, pre-amplifier, micro-processor block for data handling and absorbed dose calculation using the calibration factor of diamond detector in terms of absorbed dose to water. Dosimeter has the possibility to work with PC using standard RS-232 interface. The main features of the dosimeter are as follows: the range of dose rate measurements for photon, electron and proton beams is within 0.01-1.0 Gy/s; the energy ranges for photons are 0.08-25 MeV, and 4-25 MeV for electrons, with energy dependence no more than ±2%; the main uncertainty of the dose measurements is within ±2%; the pre-irradiation dose for diamond detector is no more than 10 Gy; the sensitive volume of the used diamond detectors is within 1-5 mm 3 ; the weight of the dosimeter no more than 2 kg. The new dosimeter was evaluated at the Central Research Institute of Roentgenology and Radiology, St. Petersburg, Russia to verify its performance. The dosimeter was used as a reference instrument for dose measurements at Cobalt-60 unit, SL75-5 and SL-20 linear accelerators and the test results have shown that the device have met the specifications. It is planned to produce dosimeter as serial device by

  5. Role of gel dosimeters in boron neutron capture therapy

    International Nuclear Information System (INIS)

    Khajeali, Azim; Farajollahi, Ali Reza; Khodadadi, Roghayeh; Kasesaz, Yaser; Khalili, Assef

    2015-01-01

    Gel dosimeters have acquired a unique status in radiotherapy, especially with the advent of the new techniques in which there is a need for three-dimensional dose measurement with high spatial resolution. One of the techniques in which the use of gel dosimeters has drawn the attention of the researchers is the boron neutron capture therapy. Exploring the history of gel dosimeters, this paper sets out to study their role in the boron neutron capture therapy dosimetric process. - Highlights: • Gel dosimeters have been investigated. • Conventional dosimetric proses of BNCT has been investigated. • Role of gel dosimeters in BNCT has been investigated

  6. Directional Radiation Dosimeter for Area and Environmental Monitoring

    International Nuclear Information System (INIS)

    Manzoli, J.E.; Campos, V.P.; Moura, E.S.

    2009-01-01

    It is presented a dosimeter that is able to measure the photon exposure and the direction from where the radiation came from. Preliminary measurements performed by this new directional radiation dosimeter demonstrate its application. This dosimeter consists of a small lead cube with thermoluminescent discs on each face, placed in well known coordinates. Only one dosimeter of this kind indicates the direction of the radiation beam, if it came from a unique position. This study was conducted inside the radiation room of a Cobalt-60 Gamma Irradiator and the dosimeter indicated the source position

  7. Predictors of Percutaneous Catheter Drainage (PCD) after Abdominal Paracentesis Drainage (APD) in Patients with Moderately Severe or Severe Acute Pancreatitis along with Fluid Collections

    Science.gov (United States)

    Liu, Wei-hui; Wang, Tao; Yan, Hong-tao; Chen, Tao; Xu, Chuan; Ye, Ping; Zhang, Ning; Liu, Zheng-cai; Tang, Li-jun

    2015-01-01

    Aims Although we previously demonstrated abdominal paracentesis drainage (APD) preceding percutaneous catheter drainage (PCD) as the central step for treating patients with moderately severe (MSAP) or severe acute pancreatitis (SAP), the predictors leading to PCD after APD have not been studied. Methods Consecutive patients with MSAP or SAP were recruited between June 2011 and June 2013. As a step-up approach, all patients initially received medical management, later underwent ultrasound-guided APD before PCD, if necessary, followed by endoscopic necrosectomy through the path formed by PCD. APD primarily targeted fluid in the abdominal or pelvic cavities, whereas PCD aimed at (peri)pancreatic fluid. Results Of the 92 enrolled patients, 40 were managed with APD alone and 52 received PCD after APD (14 required necrosectomy after initial PCD). The overall mortality was 6.5%. Univariate analysis showed that among the 20 selected parameters, 13 factors significantly affected PCD intervention after APD. Multivariate analysis revealed that infected (peri)pancreatic collections (P = -0.001), maximum extent of necrosis of more than 30% of the pancreas (P = -0.024), size of the largest necrotic peri(pancreatic) collection (P = -0.007), and reduction of (peri)pancreatic fluid collections by collections, a largest necrotic peri(pancreatic) collection of more than 100 ml, and reduction of (peri)pancreatic fluid collections by <50% after APD could effectively predict the need for PCD in the early course of the disease. PMID:25659143

  8. Dental tissue as a thermoluminescence dosimetry dosimeter

    International Nuclear Information System (INIS)

    Solaimani, F.; Zahmatkesh, M.H.; Akhlaghpoor, Sh.

    2003-01-01

    Background: Thermoluminescence dosimetry is one of the dosimetry procedures used widely as routine and personal dosimeters. In order to extend this kind of dosimeters, dental tissue has been examined and was found promising as a Thermoluminescence Dosimetry dosimeter. Materials and Methods: In this study, 70 health teeth were collected. The only criterion, wich was considered for selection of the teeth, was the healthiness of them regardless of age and gender of the donors. All collected samples were washed and cleaned and milled uniformly. The final powder had a uniform grain size between 100-300 micrometer. The sample was divided into four groups. Group A and B were used for measurement of density and investigation of variation of thermoluminescent characteristics with temperature respectively. Groups C and D were used for investigation of variation of thermoluminescent intensity with dose and fading of this intensity with time. In all cases the results obtained with dental tissue were compared to a standard LiF, thermoluminescence dosimetry dosimeter. Results: It was found that, average density of the dental tissue was 1.570 g/cm 3 , which is comparable to density of LiF, which is 1.612g/cm 3 . It was also concluded that the range of 0-300 d ig C , dental tissue has a simple curve with two specific peaks at 140 and 25 d ig C respectively. The experiment also showed that, the variation of relative intensity versus dose is linear in the range of 0.04-0.1 Gy. The fading rate of dental tissue is higher than LiF but still in the acceptable range (14% per month in compare to 5.2% per month). Conclusion: Dental tissue as a natural dosimeter is comparable with Thermoluminescence Dosimetry and can be used in accidental events with a good approximation

  9. Performance comparisons of selected personnel-dosimetry systems in use at Department of Energy facilities

    International Nuclear Information System (INIS)

    Roberson, P.L; Holbrook, K.L.; Yoder, R.C.; Fox, R.A.; Hadley, R.T.; Hogan, B.T.; Hooker, C.D.

    1983-10-01

    Dosimeter performance data were collected to help develop a uniform approach to the calibration and use of personnel dosimetry systems for Department of Energy (DOE) laboratories. Eleven DOE laboratories participated in six months of testing using the American National Draft Standard, Criteria for Testing Personnel Dosimetry Performance, ANSI N13.11, and additional testing categories. The tests described in ANSI N13.11 used a pass/fail system to determine compliance with the draft standard. Recalculation to PNL irradiations showed that the 137 Cs, 90 Sr/ 90 Y, and 252 Cf categories can be recalibrated to have acceptable performance for nearly all participant systems. Deficient dosimeter design or handling techniques caused poor performance in the x-ray category for nearly half of the participants. Too little filtration for the deep-dose element caused poor performance in the beta/photon mixture category for one participant. Two participants had excessively high standard deviations in the neutron category due to dosimeter design or handling deficiencies. The participating dosimetry systems were separated into three categories on their dose evaluation procedure for low-energy photons. These were film dosimeters, fixed-calibration thermoluminescent (TL) dosimeters, and variable-calibration TL dosimeters. The performance of the variable-calibration design was best while the film dosimeters performed considerably worse than either TL dosimeter design. Beta energy dependence studies confirmed a strong correlation between sensitive element thickness, shallow element filtration and low-energy beta response. Studies of neutron calibration conditions for each participant suggested a relationship between response and calibration facility design

  10. Evaluation of LLNL's Nuclear Accident Dosimeters at the CALIBAN Reactor September 2010

    International Nuclear Information System (INIS)

    Hickman, D.P.; Wysong, A.R.; Heinrichs, D.P.; Wong, C.T.; Merritt, M.J.; Topper, J.D.; Gressmann, F.A.; Madden, D.J.

    2011-01-01

    The Lawrence Livermore National Laboratory uses neutron activation elements in a Panasonic TLD holder as a personnel nuclear accident dosimeter (PNAD). The LLNL PNAD has periodically been tested using a Cf-252 neutron source, however until 2009, it was more than 25 years since the PNAD has been tested against a source of neutrons that arise from a reactor generated neutron spectrum that simulates a criticality. In October 2009, LLNL participated in an intercomparison of nuclear accident dosimeters at the CEA Valduc Silene reactor (Hickman, et.al. 2010). In September 2010, LLNL participated in a second intercomparison of nuclear accident dosimeters at CEA Valduc. The reactor generated neutron irradiations for the 2010 exercise were performed at the Caliban reactor. The Caliban results are described in this report. The procedure for measuring the nuclear accident dosimeters in the event of an accident has a solid foundation based on many experimental results and comparisons. The entire process, from receiving the activated NADs to collecting and storing them after counting was executed successfully in a field based operation. Under normal conditions at LLNL, detectors are ready and available 24/7 to perform the necessary measurement of nuclear accident components. Likewise LLNL maintains processing laboratories that are separated from the areas where measurements occur, but contained within the same facility for easy movement from processing area to measurement area. In the event of a loss of LLNL permanent facilities, the Caliban and previous Silene exercises have demonstrated that LLNL can establish field operations that will very good nuclear accident dosimetry results. There are still several aspects of LLNL's nuclear accident dosimetry program that have not been tested or confirmed. For instance, LLNL's method for using of biological samples (blood and hair) has not been verified since the method was first developed in the 1980's. Because LLNL and the other DOE

  11. Performance of neutron and gamma personnel dosimetry in mixed radiation fields

    International Nuclear Information System (INIS)

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

    1981-01-01

    From 1974 to 1980, six personnel dosimetry intercomparison studies (PDIS) were conducted at the Oak Ridge National Laboratory (ORNL) to evaluate the performance of personnel dosimeters in a variety of neutron and gamma fields produced by operating the Health Physics Research Reactor (HPRR) in the steady state mode with and without spectral modifying shields. A total of 58 different organizations participated in these studies which produced approximately 2000 measurements of neutron and gamma dose equivalents on anthropomorphic phantoms for five different reactor spectra. Based on these data, the relative performance of three basic types of neutron dosimeters [nuclear emulsion film, thermoluminescent (TLD), and track-etch] and two basic types of gamma dosimeters (film and TLD) in mixed radiation fields was assessed

  12. Geiger-mode APD camera system for single-photon 3D LADAR imaging

    Science.gov (United States)

    Entwistle, Mark; Itzler, Mark A.; Chen, Jim; Owens, Mark; Patel, Ketan; Jiang, Xudong; Slomkowski, Krystyna; Rangwala, Sabbir

    2012-06-01

    The unparalleled sensitivity of 3D LADAR imaging sensors based on single photon detection provides substantial benefits for imaging at long stand-off distances and minimizing laser pulse energy requirements. To obtain 3D LADAR images with single photon sensitivity, we have demonstrated focal plane arrays (FPAs) based on InGaAsP Geiger-mode avalanche photodiodes (GmAPDs) optimized for use at either 1.06 μm or 1.55 μm. These state-of-the-art FPAs exhibit excellent pixel-level performance and the capability for 100% pixel yield on a 32 x 32 format. To realize the full potential of these FPAs, we have recently developed an integrated camera system providing turnkey operation based on FPGA control. This system implementation enables the extremely high frame-rate capability of the GmAPD FPA, and frame rates in excess of 250 kHz (for 0.4 μs range gates) can be accommodated using an industry-standard CameraLink interface in full configuration. Real-time data streaming for continuous acquisition of 2 μs range gate point cloud data with 13-bit time-stamp resolution at 186 kHz frame rates has been established using multiple solid-state storage drives. Range gate durations spanning 4 ns to 10 μs provide broad operational flexibility. The camera also provides real-time signal processing in the form of multi-frame gray-scale contrast images and single-frame time-stamp histograms, and automated bias control has been implemented to maintain a constant photon detection efficiency in the presence of ambient temperature changes. A comprehensive graphical user interface has been developed to provide complete camera control using a simple serial command set, and this command set supports highly flexible end-user customization.

  13. An Ultraviolet Excess in the Superluminous Supernova Gaia16apd Reveals a Powerful Central Engine

    Energy Technology Data Exchange (ETDEWEB)

    Nicholl, M.; Berger, E.; Blanchard, P. K.; Milisavljevic, D.; Challis, P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States); Margutti, R. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Metzger, B. D. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Chornock, R., E-mail: matt.nicholl@cfa.harvard.edu [Astrophysical Institute, Department of Physics and Astronomy, 251B Clippinger Lab, Ohio University, Athens, OH 45701 (United States)

    2017-01-20

    Since the discovery of superluminous supernovae (SLSNe) in the last decade, it has been known that these events exhibit bluer spectral energy distributions than other supernova subtypes, with significant output in the ultraviolet. However, the event Gaia16apd seems to outshine even the other SLSNe at rest-frame wavelengths below ∼3000 Å. Yan et al. have recently presented HST UV spectra and attributed the UV flux to low iron-group abundance in the outer ejecta, and hence reduced line blanketing. Here, we present UV and optical light curves over a longer baseline in time, revealing a rapid decline at UV wavelengths despite a typical optical evolution. Combining the published UV spectra with our own optical data, we demonstrate that Gaia16apd has a much hotter continuum than virtually any SLSN at maximum light, but it cools rapidly thereafter and is indistinguishable from the others by ∼10–15 days after peak. Comparing the equivalent widths of UV absorption lines with those of other events, we show that the excess UV continuum is a result of a more powerful central power source, rather than a lack of UV absorption relative to other SLSNe or an additional component from interaction with the surrounding medium. These findings strongly support the central-engine hypothesis for hydrogen-poor SLSNe. An explosion ejecting M {sub ej} = 4.8(0.2/ κ ) M {sub ⊙}, where κ is the opacity in cm{sup 2} g{sup −1}, and forming a magnetar with spin period P = 2 ms, and B = 2 × 10{sup 14} G (lower than other SLSNe with comparable rise times) can consistently explain the light curve evolution and high temperature at peak. The host metallicity, Z = 0.18 Z {sub ⊙}, is comparable to other SLSNe.

  14. Design and implementation of Gm-APD array readout integrated circuit for infrared 3D imaging

    Science.gov (United States)

    Zheng, Li-xia; Yang, Jun-hao; Liu, Zhao; Dong, Huai-peng; Wu, Jin; Sun, Wei-feng

    2013-09-01

    A single-photon detecting array of readout integrated circuit (ROIC) capable of infrared 3D imaging by photon detection and time-of-flight measurement is presented in this paper. The InGaAs avalanche photon diodes (APD) dynamic biased under Geiger operation mode by gate controlled active quenching circuit (AQC) are used here. The time-of-flight is accurately measured by a high accurate time-to-digital converter (TDC) integrated in the ROIC. For 3D imaging, frame rate controlling technique is utilized to the pixel's detection, so that the APD related to each pixel should be controlled by individual AQC to sense and quench the avalanche current, providing a digital CMOS-compatible voltage pulse. After each first sense, the detector is reset to wait for next frame operation. We employ counters of a two-segmental coarse-fine architecture, where the coarse conversion is achieved by a 10-bit pseudo-random linear feedback shift register (LFSR) in each pixel and a 3-bit fine conversion is realized by a ring delay line shared by all pixels. The reference clock driving the LFSR counter can be generated within the ring delay line Oscillator or provided by an external clock source. The circuit is designed and implemented by CSMC 0.5μm standard CMOS technology and the total chip area is around 2mm×2mm for 8×8 format ROIC with 150μm pixel pitch. The simulation results indicate that the relative time resolution of the proposed ROIC can achieve less than 1ns, and the preliminary test results show that the circuit function is correct.

  15. Sci-Sat AM(1): Imaging-08: Small animal APD PET detector with submillimetric resolution for molecular imaging.

    Science.gov (United States)

    Bérard, P; Bergeron, M; Pepin, C M; Cadorette, J; Tétrault, M-A; Viscogliosi, N; Fontaine, R; Dautet, H; Davies, M; Lecomte, R

    2008-07-01

    Visualization and quantification of biological processes in mice, the preferred animal model in most preclinical studies, require the best possible spatial resolution in positron emission tomography (PET). A new 64-channel avalanche photodiode (APD) detector module was developed to achieve submillimeter spatial resolution for this purpose. The module consists of dual 4 × 8 APD arrays mounted in a custom ceramic holder. Individual APD pixels having an active area of 1.1 × 1.1 mm2 at a 1.2 mm pitch can be fitted to an 8 × 8 LYSO scintillator block designed to accommodate one-to-one coupling. An analog test board with four 16-channel preamplifier ASICs was designed to be interfaced with the existing LabPET digital processing electronics. At a standard APD operating bias, a mean energy resolution of 27.5 ± 0.6% was typically obtained at 511 keV with a relative standard deviation of 13.8% in signal amplitude for the 64 individual pixels. Crosstalk between pixels was found to be well below the typical lower energy threshold used for PET imaging applications. With two modules in coincidence, a global timing resolution of 5.0 ns FWHM was measured. Finally, an intrinsic spatial resolution of 0.8 mm FWHM was measured by sweeping a 22Na point source between two detector arrays. The proposed detector module demonstrates promising characteristics for dedicated mouse PET imaging at submillimiter resolution. © 2008 American Association of Physicists in Medicine.

  16. Penyusunan Perencanaan Keberlangsungan Bisnis PT PLN (Persero APD Jateng dan DIY dengan ISO 22301 dan Metode OCTAVE

    Directory of Open Access Journals (Sweden)

    Azmi Afifah Zahra

    2017-01-01

    Full Text Available Abstrak— Penelitian dalam tugas akhir ini adalah melakukan penyusunan perencanaan keberlangsungan bisnis teknologi informasi pada PT PLN (Persero APD Jateng dan DIY dengan berbasis risiko sebagai bentuk kesiapan perusahaan dalam menangani risiko dan dampak bisnis yang mengancam perusahaan. PT PLN (Persero APD Jateng dan DIY menggunakan sistem dan layanan TI sebagai daya dukung perusahaan dalam mencapai tujuannya. Penggunaan sistem dan layanan TI tersebut tidak terlepas dari adanya ancaman pada risiko sistem dan layanan TI serta dampak dari proses bisnis yang dijalankan oleh tiap fungsi bisnis perusahaan. Dalam proses penyusunan untuk perencanaan keberlangsungan bisnis akan dibuat terlebih dahulu alur kerja untuk kegiatan pengelolaan keberlangsungan bisnis (Business Continuity Management untuk PT PLN (Persero APD Jateng dan DIY dengan menggunakan acuan ISO 22301: 2012 dan alur kerja yang telah diterapkan oleh perusahaan lain yaitu dari Perusahaan Chubu Electric Power Company Group dan DHS Electricity dengan tetap memberikan prosedur praktis yang dapat disesuaikan oleh PT PLN (Persero APD Jateng dan DIY. Hasil akhir dari penelitian ini adalah berupa rekomendasi penerapan alur kerja dan strategi keberlangsungan bisnis untuk PT PLN (Persero berdasarkan pada risiko aset TI yang menjadi tanggung jawab tim SCADA dan Telekomunikasi.

  17. FACT - Status and experience from five years of operation of the first G-APD Cherenkov Telescope

    Science.gov (United States)

    Neise, D.; Adam, J.; Ahnen, M. L.; Baack, D.; Balbo, M.; Bergmann, M.; Biland, A.; Blank, M.; Bretz, T.; Brügge, K. A.; Buss, J.; Dmytriiev, A.; Dorner, D.; Einecke, S.; Hempfling, C.; Hildebrand, D.; Hughes, G.; Linhoff, L.; Mannheim, K.; Müller, S.; Neronov, A.; Nöthe, M.; Paravac, A.; Pauss, F.; Rhode, W.; Shukla, A.; Temme, F.; Thaele, J.; Walter, R.

    2017-12-01

    The First G-APD Cherenkov Telescope (FACT) demonstrates the usability of novel Geiger-mode operated Avalanche Photo Diodes (G-APD, often called SiPM) for Imaging Atmospheric Cherenkov Telescopes (IACT). The camera consists of 1440 pixels with dedicated electronics operating at 2 Giga samples per second. It is installed on the refurbished HEGRA telescope with a mirror area of ≈ 9.5m2 on the Canary Island La Palma. FACT is taking data almost every night since the camera was installed in October 2011. It was possible to improve the data taking efficiency to very high values due to the very stable and reliable operation. This also allows to operate FACT remotely without any need for operators on site. Even remote human intervention became less and less frequent over the years, allowing operation to become mostly automatic. FACT is monitoring the long-term behavior of some very-high energy variable extra-galactic sources with unparalleled sampling density as well as testing the behavior of the sensors under severe weather conditions. Due to the long exposure of FACT's G-APDs under strong moonlight conditions it was possible to evaluate the aging effects of G-APDs due to collected charge. No indication of aging was found. No external calibration device is needed to operate FACT since the properties of the sensors themselves allow for a high precision self-calibration of the camera.

  18. The New HARSHAW Extremity Dosimeters for Gamma and Beta Ray Monitoring

    International Nuclear Information System (INIS)

    Fellinger, J.; Majewski, M.; Rotunda, J.; Tawi, R.

    1997-01-01

    Large personnel dosimetry services providing extremity monitoring with finger rings based on thermoluminescent detectors have long been looking for a practical method for automated reading including automated identification of the detectors.All existing methods are at least not very suitable for medical applications, particularly for surgery, due to the fact that cold sterilization is usually impossible.Bicron radiation Measurement Products developed in co-operation with the Austrian Research Centre Seibersdorf a new finger ring dosimeter DXT-RAD as a fast and economic solution for fully automated evaluation of extremity dosemeters. (authors)

  19. Review of the current deficiencies in personnel beta dosimetry, with recommendations

    International Nuclear Information System (INIS)

    Sherbini, S.; Porter, S.W.

    1983-06-01

    The report describes the design and use of personnel dosimeters used by the nuclear power industry to monitor occupational radiation exposure. It then shows why the monitoring method is inaccurate when personnel are exposed to beta particles. Then the report describes alternatives that would lead to improved measurements. The report also critiques the dosimetry processor testing criteria developed by the Health Physics Society Standards Committee. Survey instruments are shown often to be inaccurate when used to measure beta dose rates

  20. Comparison of alanine dosimeters using silicone as their binder to a commercial, polystyrene-bound, alanine dosimeter

    International Nuclear Information System (INIS)

    Galindo, S.; Urena-Nunez, F.

    1997-01-01

    The feasibility of practical boron-containing alanine ESR dosimeters for gamma-neutron mixed field irradiation dosimeters depends in part on whether the γ response characteristics of these silicone-bound dosimeters are comparable to those of a commercially available dosimeter that has been used by the International Atomic Energy Agency (International Dose Assurance Service) as a transfer reference dosimeter. This work presents the results of the comparison of 3 batches of silicone-bound alanine dosimeters. The first batch consists of a mixture of alanine and boric acid; the second, alanine and borax; and the last contains only alanine. Results indicate that γ response characteristics of the silicone-bound samples are comparable to those of the commercial, polystyrene-bound, alanine dosimeter and that silicone has a strong potential as a binding substance for alanine ESR dosimetry. (Author)

  1. Quantitative relations between beta-gamma mixed-field dosimeter responses and dose-equivalent conversion factors according to the testing standard

    International Nuclear Information System (INIS)

    Gupta, V.P.

    1982-08-01

    The conventional two-element personnel dosimeters, usually having two thick TLD (thermoluminescent dosimetry) ribbons, are used extensively for radiation protection dosimetry. Many of these dosimeters are used for the measurement of beta and gamma radiation doses received in mixed beta-gamma fields. Severe limitations exist, however, on the relative magnitudes and energies of these fields that may be measured simultaneously. Moreover, due to a well-known energy dependence of these dosimeters, particularly for the beta-radiations, systematic errors will occur whenever the differences in workplaces and calibration radiation energies exist. A simple mathematical approach is presented to estimate the deep and shallow dose equivalent values at different energies for such dosimeters. The formulae correlate the dosimeter responses and dose equivalent conversion factors at different energies by taking into account the guidelines of the adopted ANSI Standard N13.11 and the dosimetry practices followed by most dosimeter processors. This standard is to be used in a mandatory testing program in the United States

  2. Development of a new personnel dosemeter with Ca So4:Dy+ PTFE

    International Nuclear Information System (INIS)

    Cardenete, C.M.

    1992-01-01

    A new personnel dosimeter was developed with substitution plane geometric in metallic filters. The evaluation method was based in linear comparison of responses over several filters. This method was tested, simulating fields of mixed energy, and it was obtained an average derivation of (11+-5)% and lower derivations to 20% in all calibration interval. (C.G.C.)

  3. Intercomparison of personnel dosimetry for thermal neutron dose equivalent in neutron and gamma-ray mixed fields

    International Nuclear Information System (INIS)

    Ogawa, Yoshihiro

    1985-01-01

    In order to consider the problems concerned with personnel dosimetry using film badges and TLDs, an intercomparison of personnel dosimetry, especially dose equivalent responses of personnel dosimeters to thermal neutron, was carried out in five different neutron and gamma-ray mixed fields at KUR and UTR-KINKI from the practical point of view. For the estimation of thermal neutron dose equivalent, it may be concluded that each personnel dosimeter has good performances in the precision, that is, the standard deviations in the measured values by individual dosimeter were within 24 %, and the dose equivalent responses to thermal neutron were almost independent on cadmium ratio and gamma-ray contamination. However, the relative thermal neutron dose equivalent of individual dosimeter normalized to the ICRP recommended value varied considerably and a difference of about 4 times was observed among the dosimeters. From the results obtained, it is suggested that the standardization of calibration factors and procedures is required from the practical point of radiation protection and safety. (author)

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

    International Nuclear Information System (INIS)

    Barjaktarovic, N.

    1988-02-01

    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

  5. Radiation Dose Measurement Using Chemical Dosimeters

    International Nuclear Information System (INIS)

    Lee, Min Sun; Kim, Eun Hee; Kim, Yu Ri; Han, Bum Soo

    2010-01-01

    The radiation dose can be estimated in various ways. Dose estimates can be obtained by either experiment or theoretical analysis. In experiments, radiation impact is assessed by measuring any change caused by energy deposition to the exposed matter, in terms of energy state (physical change), chemical production (chemical change) or biological abnormality (biological change). The chemical dosimetry is based on the implication that the energy deposited to the matter can be inferred from the consequential change in chemical production. The chemical dosimetry usually works on the sample that is an aqueous solution, a biological matter, or an organic substance. In this study, we estimated absorbed doses by quantitating chemical changes in matter caused by radiation exposure. Two different chemical dosimeters, Fricke and ECB (Ethanol-Chlorobenzene) dosimeter, were compared in several features including efficacy as dose indicator and effective dose range

  6. Sensitive color dosimeters using photochromic diarylethenes

    International Nuclear Information System (INIS)

    Irie, Setsuko; Irie, Masahiro

    2008-01-01

    Various types of color dosimeters are conveniently used for estimating absorbed dose in the radiation sterilization of biomedical materials. Diarylethenes with heterocyclic aryl groups are extensively studied for the applications to the optoelectronic devices, such as optical memory media and photowitching devices because of their thermally irreversible and fatigue-resistant properties. The colors of diarylethenes never fade in the dark conditions. The thermally stable dithienylethene derivatives are applied to sensitive color dosimeters. Upon γ-irradiation, polystyrene films containing diarylethene derivatives, such as 1,2-bis(2-methyl-5-phenyl-3-thienyl) perfluorocyclopentene 1 or 1,2-bis(2,5-dimethyl-3-thienyl) perfluorocyclopentene 2, and fluorescent metal complexes turned blue or red. Even if the absorbed dose was as small as 10 Gy, a clear color change was observed. (author)

  7. Small is beautiful: SAIC's new dosimeter

    International Nuclear Information System (INIS)

    Benson, R.G.

    1991-01-01

    Science Applications International Corporation (California) has developed an energy-compensated Geiger tube in a package the size of a small pocket pager. In fact, the whole dosimeter measures just 48mm x 72mm x 17mm. The rugged, lightweight unit is sensitive enough to record radiation ranging from low background levels caused by the earth's surface, the sun, or cosmic radiation, to beyond lethal dose levels. The PD-1 provides dose measurement, dose rate measurement, and ''chip'' functions. A chirper sounds each time a specified dose is accumulated, and the chirp increments are defined by the user. A dosimeter reader provides a simple interface for bi-directional communication with host PC. The Geiger tube provides improved accuracy over a wider energy range than current solid state devices. Features such as long battery life, long calibration life (two years or longer), and easy calibration procedure should help to simplify the work of health physicists overseeing dosimetry management programmes. (author)

  8. Individual dosimeter for radon and thoron daughters

    International Nuclear Information System (INIS)

    Chapuis, A.M.; Duport, P.; Zettwoog, P.

    1979-01-01

    The dosimeter is designed for the continuous measurement of the concentration of α emitters from the uranium 238 and thorium 232 series. It enables the measurement of, firstly the aerosol concentration of 218 Po (Radium A), 214 Po (Radium C') and 212 Po (Thorium C') and secondly the activity of long-lived α emitters in aerosols coming from ore dusts. One light weight version of this dosimeter is autonomous for 18 hours and is designed to measure individual doses, due to inhalation, for workers employed in uranium mines and ore processing plants. An other version using the same sampling head allows the monitoring of air concentrations in working environments. Living quarters, or free air

  9. Human hair as a pollutant dosimeter

    International Nuclear Information System (INIS)

    Al-Hashimi, A.

    1991-01-01

    Human hair has been proved to be a better dosimeter than even blood for tracing most of the heavy metal toxins when they penetrate the biosphere. The high precision of the neutron activation analysis (NAA) enabled researchers to elegantly differentiate between endogenous and exogenous contamination and thoroughly study poisonings caused by these physiologically-unimportant elements. Extensive volume of bench-scale work has been accomplished in these laboratories to show the capacity of INAA to detect the presence of 10 nuclides (or more) with a precision of about 5%. The principal objective of the present study is to employ this assaying power and the tendency of scalp hair to uptake heavy metals from aqueous solutions, to design a dosimeter which can easily be used by the environmentalists. The findings should also be of interest to the waste-management people who are searching for a cost-effective technique to remove these pollutants from relatively large volumes of industrial effluents

  10. High dose potassium-nitrate chemical dosimeter

    International Nuclear Information System (INIS)

    Dorda de Cancio, E.M.; Munoz, S.S.

    1982-01-01

    This dosimeter is used to control 10 kGY-order doses (1 Mrad). Nitrate suffers a radiolitic reduction phenomena, which is related to the given dose. The method to use potassium nitrate as dosimeter is described, as well as effects of the temperature of irradiation, pH, nitrate concentration and post-irradiation stability. Nitrate powder was irradiated at a Semi-Industrial Plant, at Centro Atomico Ezeiza, and also in a Gammacell-220 irradiator. The dose rates used were 2,60 and 1,80 KGY/hour, and the given doses varied between 1,0 and 150 KGY. The uncertainty was +-3% in all the range. (author) [es

  11. Selfcalibrated alanine/EPR dosimeters. A new generation of solid state/EPR dosimeters

    International Nuclear Information System (INIS)

    Yordanov, N.D.; Gancheva, V.

    1999-01-01

    Alanine/EPR dosimeters are well established as secondary, reference dosimeters for high-energy radiation. However, there are various sources of uncertainty in the evaluation of absorbed dose. This arises primarily from the necessity to calibrate each EPR spectrometer and each batch of dosimeters before their use. In order to overcome this disadvantage, a new generation alanine/EPR dosimeter has been developed, and its possibilities as a radiation detector are reported. Principally, it is a mixture of alanine, some quantity of EPR active substance, and a binding material. The EPR active substance, acting as an internal EPR standard, is chosen to have EPR parameters which are independent of the irradiation dose. The simultaneous recording of the spectra of both the sample and the standard under the same experimental conditions and the estimation of the ratio I alanine /I Mn as a function of the absorbed dose strongly reduces the uncertainties. The response of these dosimeters for 60 Co γ-radiation exhibits excellent linearity and reproducibility in the range of absorbed dose, 10 2 - 5 x 10 4 Gy. (author)

  12. Phosphor for thermoluminescent type radiation dosimeter

    International Nuclear Information System (INIS)

    Nada, N.; Yamashita, T.

    1975-01-01

    This has the accumulation effect of radiation energy and is mainly used as the element for thermoluminescent type radiation dosimeters. It has as the principal constituent a phosphor consisting of calcium sulfate as the principal constituent and other impurity elements such as dysprosium, thulium and the like. It is more sensitive by the order of 1 to 2 or more figures than the conventional ones and is excellent in the retention of absorbed radiation energy. (U.S.)

  13. Dosimeter characteristics and service performance requirements

    International Nuclear Information System (INIS)

    Ambrosi, P.; Bartlett, D.T.

    1999-01-01

    The requirements for personal dosimeters and dosimetry services given by ICRP 26, ICRP 35, ICRP 60 and ICRP 75 are summarised and compared with the requirements given in relevant international standards. Most standards could be made more relevant to actual workplace conditions. In some standards, the required tests of energy and angular dependence of the response are not sufficient, or requirements on overall uncertainty are lacking. (author)

  14. Color-indicator dosimeter for ionizing radiation

    International Nuclear Information System (INIS)

    Panchenkov, G.M.; Kozlov, L.L.; Molin, A.A.; Ershova, Z.F.; Mikhailov, L.M.; Juzvyak, A.G.; Valitov, R.B.; Churov, V.P.; Grinev, M.P.

    1980-01-01

    Colorimetric dosimeter of ionizing radiation, containing 70-100 w % of a thermoplastic polymer, 10-40 w. % of a softener, 0.5-3.0 w. % of stabilizer and two dyes compatible with the polymer is designed. The first dye is chosen among zanthene- polymethine- or pyrazolon dyes, while the other is a triarylmethane- indigo- thiazine- indophenol- indiamine- or indaniline dye. (E.G.)

  15. Conceptual design of the SMART dosimeter

    Science.gov (United States)

    Johnson, Erik B.; Vogel, Sam; Frank, Rebecca; Stoddard, Graham; Vera, Alonzo; Alexander, David; Christian, James

    2017-08-01

    Active dosimeters for astronauts and space weather monitors are critical tools for mitigating radiation induced health issues or system failure on capital equipment. Commercial spaceflight, deep space flight, and satellites require smarter, smaller, and lower power dosimeters. There are a number of instruments with flight heritage, yet as identified in NASA's roadmaps, these technologies do not lend themselves to a viable solution for active dosimetry for an astronaut, particularly for deep space missions. For future missions, nano- and micro-satellites will require compact instruments that will accurately assess the radiation hazard without consuming major resources on the spacecraft. RMD has developed the methods for growing an advanced scintillation material called phenylcarbazole, which provides pulse shape discrimination between protons and electrons. When used in combination with an anti-coincidence detector system, an assessment of the dose from charged ions and neutral particles can be determined. This is valuable as damage on a system (such as silicon or tissue) is dependent on the particle species. Using this crystal with readout electronics developed in partnership with COSMIAC at the University of New Mexico, the design of the Small Mixed field Autonomous Radiation Tracker (SMART) Dosimeter consists of a low-power analog to digital conversion scheme with low-power digital signal processing algorithms, which are to be implemented within a compact system on a chip, such as the Xilinx Zynq series. A review of the conceptual design is presented.

  16. Use of Fall-Risk Inducing Drugs in Patients Using Anti-Parkinson Drugs (APD: A Swedish Register-Based Study.

    Directory of Open Access Journals (Sweden)

    Ylva Haasum

    Full Text Available Many drugs increase the risk of falls in old age. Although persons with Parkinson's disease (PD are at increased risk of experiencing falls and fractures, the use of fall-risk inducing drugs (FRIDs in this population has not previously been investigated. The objective of this study was to investigate the burden of use of FRIDs in older persons treated with anti-Parkinson drugs (APD; used as a proxy for PD, compared to persons without APD.We analyzed individual data on age, sex, type of housing and drug use in 1 346 709 persons aged ≥ 65 years in the Swedish Prescribed Drug Register on the date of 30 September 2008. Main outcome measure was the use of FRIDs.FRIDs were used by 79% of persons with APD and 75% of persons without APD. Persons with APD were more likely to use ≥ 1 FRIDs compared to persons without APD (adjusted OR: 1.09; 95% CI: 1.06-1-12. The association was stronger for concomitant use of ≥ 5 FRIDS (adjusted OR: 1.49; 95% CI: 1.44-1.55.The high use of FRIDs among persons with APD indicates that these patients may be at increased risk of drug-induced falls. Further studies are needed to investigate how these drugs affect the risk of falling in persons with PD.

  17. Solid state neutron dosimeter for space applications. Final Report

    International Nuclear Information System (INIS)

    Entine, G.; Nagargar, V.; Sharif, D.

    1990-08-01

    Personnel engaged in space flight are exposed to significant flux of high energy neutrons arising from both primary and secondary sources of ionizing radiation. Presently, there exist no compact neutron sensor capable of being integrated in a flight instrument to provide real time measurement of this radiation flux. A proposal was made to construct such an instrument using special PIN silicon diode which has the property of being insensitive to the other forms of ionizing radiation. Studies were performed to determine the design and construction of a better reading system to allow the PIN diode to be read with high precision. The physics of the device was studied, especially with respect to those factors which affect the sensitivity and reproducibility of the neutron response. This information was then used to develop methods to achieve high sensitivity at low neutron doses. The feasibility was shown of enhancing the PIN diode sensitivity to make possible the measurement of the low doses of neutrons encountered in space flights. The new PIN diode will make possible the development of a very compact, accurate, personal neutron dosimeter

  18. An ESR study on biological dosimeters: Human hair

    International Nuclear Information System (INIS)

    Colak, Seyda; Ozbey, Turan

    2011-01-01

    In the present work, characteristic features of the radicals found in untreated, gamma and UV-irradiated and mechanical damaged human hair samples were investigated by ESR spectroscopy. Heights of the resonance peaks measured with respect to the spectrum base line were used to monitor microwave power, dose-response, storage time and temperature dependent kinetic features of the radical species contributing to the formation of recorded experimental ESR spectra. Peak heights and g-values (2.0037-2.0052) determined from recorded spectra of hair were color dependent with ΔHpp-0.47 mT. The act of cutting hair samples gene rates sulfur centered radicals which are found in the a-keratin structure of hair. The variations of the peak heights with temperature were related with the water content found in the hair samples. In the 6-1100 Gy dose range, a linear + quadratic dose-response curve was recorded for hair and the mean radiation yield (G mean ) was calculated to be 0.4. The gamma radiation induced radicals were stable for a several hours at room temperature storage conditions. Based on these findings it was concluded that human hair samples could be used as biological/personnel dosimeters and that ESR spectroscopy could be successfully used as a potential technique for monitoring its dosimetric behaviours.

  19. Anthracene dosimeter characterization under radiotherapy photons

    International Nuclear Information System (INIS)

    Czelusniak, Caroline

    2011-01-01

    New radiotherapy techniques such as intensity-modulated radiation therapy and stereotactic radiosurgery have increased the need for dosimeters that can provide measurements in real time with high spatial resolution. Organic scintillation dosimeters are able to measure with accuracy small radiation fields and fields with high gradients, besides having advantages such as water and soft tissue equivalence and the possibility to be used in vivo. Anthracene is an organic scintillator crystal with the highest known scintillation efficiency among organic scintillation materials. The objective of this work is to characterize the anthracene as a dosimeter under radiotherapy photons energies, analysing its signal against average granulosity, intern capsule diameter, absorbed dose, absorbed dose rate, photon energy and its spatial resolution; with the last one analysed under three methods (edge spread function, line spread function and modulation transfer function). The photons energies used were 1.25 MeV ( 60 Co), 0.661 MeV ( 137 Cs) and X-rays (effective energies of 28.4; 46.5; 48.5; 94.0 e 106.0 keV). The scintillation detection system consisted of an optical fiber with one end attached to the anthracene capsule and the other to a photomultiplier tube maintained by power supply followed by an electrometer. Once Cerenkov radiation occurs in the optical fiber, it was removed from the total scintillation signal trough the subtraction of the signal, taken irradiating the optical fiber without the anthracene attached to one of its extremity. From results obtained, one can infer that the dosimeter signal increases proportionally with average granulosity and intern capsule diameter. The signal is linearly dependent of absorbed dose, linearly dependent of low photons energies and independent for high photons energies, as well as independent of the absorbed dose rate. From the spatial resolution values obtained it was possible to infer that the one obtained through modulation

  20. Comparison of electronic digital alarm dosimeter with TLD

    International Nuclear Information System (INIS)

    Kumar, Pankaj; Pandey, J.P.N.; Shinde, A M.; Purohit, R.G.; Sarkar, P.K.

    2012-01-01

    Control of exposure of radiation workers on day to day basis has been made easy by use of semiconductor based electronic digital dosimeter. Additional dose constraints of 10 mSv for occupational radiation workers have made it essential to use such type of digital personal monitoring devices. In addition to conventional ionisation chamber based direct reading dosimeters, additional 35 semiconductor based digital dosimeters model MGP DMC 2000 S were used for the monitoring of personal exposure of radiation workers in a spent fuel reprocessing plant. Though better least count and good performance over a wide range of dose rate are claimed by the manufacture, before making use of such dosimeter on large scale, validation of its performance is required to be checked. In this paper, an effort is made to determine the performance of digital dosimeters, by exposing these digital dosimeters in combination with TLDs at different radiation levels and obtained results were compared and analysed

  1. Novel method of using 99mTc-APD (pamidronate) to monitor delivery of bisphosphonates to bone without renal burden

    International Nuclear Information System (INIS)

    Kumar, V.; Wong, E.; Kumar, D.; Howman-Giles, R.; Little, D.G.

    2004-01-01

    Purpose: Bisphosphonates (BP) were first used in the 1960's when their ability to bind to bone mineral hydroxyapatite made them a useful tool for studying orthopaedic bone repair processes. From being an experimental agent, now BP have become the treatment of choice for clinical disorders associated with increased bone resorption, such as osteoporosis, myeloma and bone metastasis. While the effectiveness of BP in managing these disorders is commendable, they have certain undesirable side effects. For example, intravenous injection of Pamidronate may be associated with nephrocalcinosis of the kidneys. Therefore there is a need to develop a novel technique to demonstrate the localisation of the compound, which can be visualized within hours of administering into the patients. The Objective of the study is to develop 99mTc-labelled APD (Pamidronate) as a new tool and monitor its biodistribution by gamma imaging modality. This approach has not been reported elsewhere in the literature and has the potential to improve the quality of treatment currently available. Methods: Pamidronate (APD) was labelled with 99mTc-pertechnetate in the presence of Stannous Chloride as the reducing agent. The radiochemical purity (RCP) of the compound was determined by ITLC-SG/Acetone and found to be >99%. Rats were injected with 99mTc-APD intravenously (IV) subcutaneously (SC) and by direct application (Local) on surgically exposed femur. The animals were sacrificed at 2hr or 24hr post-injection and various organs were harvested and counted for radioactivity with a view to establish the biodistribution of 99mTc-APD. Results: 99mTc-APD was injected by three different modes as indicated in the Methods section. Planar and SPECT images were obtained at 2 hr and 24 hr post-injection. Intravenous injection (IV): When 99mTc-APD was administered IV, the labelled compound appeared instantly in the blood pool. The 2 hr and 24 hr images clearly showed that the labelled compound accumulated

  2. The Magnetar Model of the Superluminous Supernova GAIA16apd and the Explosion Jet Feedback Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Soker, Noam, E-mail: soker@physics.technion.ac.il [Department of Physics, Technion—Israel Institute of Technology, Haifa 32000 (Israel)

    2017-04-10

    Under the assumption that jets explode core collapse supernovae (CCSNe) in a negative jet feedback mechanism (JFM), this paper shows that rapidly rotating neutron stars are likely to be formed when the explosion is very energetic. Under the assumption that an accretion disk or an accretion belt around the just-formed neutron star launch jets and that the accreted gas spins-up the just-formed neutron star, I derive a crude relation between the energy that is stored in the spinning neutron star and the explosion energy. This relation is ( E {sub NS-spin}/ E {sub exp}) ≈ E {sub exp}/10{sup 52} erg; It shows that within the frame of the JFM explosion model of CCSNe, spinning neutron stars, such as magnetars, might have significant energy in super-energetic explosions. The existence of magnetars, if confirmed, such as in the recent super-energetic supernova GAIA16apd, further supports the call for a paradigm shift from neutrino-driven to jet-driven CCSN mechanisms.

  3. Analysis of surface dark current dependent upon surface passivation in APD based on GaAs

    International Nuclear Information System (INIS)

    Song, Hong Joo; Roh, Cheong Hyun; Lee, Jun Ho; Choi, Hong Goo; Hahn, Cheol-Koo; Kim, Dong Ho; Park, Jung Ho

    2009-01-01

    In this paper, we investigated the dependence of reverse dark current on two types of surface passivation, one of which is polyimide and the other is SiN x , for InAs quantum dots/GaAs separate absorption, charge, multiplication avalanche photodiode (SACM APD). From the experimental results, we found that dark current was dominated by surface current, and not bulk current. It was also noted that SiN x passivation has a surface current that is lower by three to nine times in magnitude than that in polyimide passivation in the whole range of bias. To analyze the difference in dark current due to the passivation types, we propose the theoretical current components. This shows that the dark current of both passivation types is mainly composed of generation–recombination (G–R) and tunneling components, originating from the surface. However, each component has a different magnitude for passivation types, which can be explained by carrier concentration and trap density. The dependence of dark current on temperature shows the different behaviors between passivation types and supports a theoretical description of current components

  4. AX-PET: A novel PET concept with G-APD readout

    CERN Document Server

    Heller, M; Casella, C; Chesi, E; De Leo, R; Dissertori, G; Fanti, V; Gillam, J E; Joram, C; Lustermann, W; Nappi, E; Oliver, J F; Pauss, F; Rafecas, M; Rudge, A; Ruotsalainen, U; Schinzel, D; Schneider, T; Seguinot, J; Solevi, P; Stapnes, S; Tuna, U; Weilhammer, P

    2012-01-01

    The AX-PET collaboration has developed a novel concept for high resolution PET imaging to overcome some of the performance limitations of classical PET cameras, in particular the compromise between spatial resolution and sensitivity introduced by the parallax error. The detector consists of an arrangement of long LYSO scintillating crystals axially oriented around the field of view together with arrays of wave length shifter strips orthogonal to the crystals. This matrix allows a precise 3D measurement of the photon interaction point. This is valid both for photoelectric absorption at 511 key and for Compton scattering down to deposited energies of about 100 keV. Crystals and WLS strips are individually read out using Geiger-mode Avalanche Photo Diodes (G-APDs). The sensitivity of such a detector can be adjusted by changing the number of layers and the resolution is defined by the crystal and strip dimensions. Two AX-PET modules were built and fully characterized in dedicated test set-ups at CERN, with point-...

  5. The Magnetar Model of the Superluminous Supernova GAIA16apd and the Explosion Jet Feedback Mechanism

    International Nuclear Information System (INIS)

    Soker, Noam

    2017-01-01

    Under the assumption that jets explode core collapse supernovae (CCSNe) in a negative jet feedback mechanism (JFM), this paper shows that rapidly rotating neutron stars are likely to be formed when the explosion is very energetic. Under the assumption that an accretion disk or an accretion belt around the just-formed neutron star launch jets and that the accreted gas spins-up the just-formed neutron star, I derive a crude relation between the energy that is stored in the spinning neutron star and the explosion energy. This relation is ( E _N_S_-_s_p_i_n/ E _e_x_p) ≈ E _e_x_p/10"5"2 erg; It shows that within the frame of the JFM explosion model of CCSNe, spinning neutron stars, such as magnetars, might have significant energy in super-energetic explosions. The existence of magnetars, if confirmed, such as in the recent super-energetic supernova GAIA16apd, further supports the call for a paradigm shift from neutrino-driven to jet-driven CCSN mechanisms.

  6. Neutron personnel dosimetry

    International Nuclear Information System (INIS)

    Griffith, R.V.

    1981-01-01

    The current state-of-the-art in neutron personnel dosimetry is reviewed. Topics covered include dosimetry needs and alternatives, current dosimetry approaches, personnel monitoring devices, calibration strategies, and future developments

  7. Personnel neutron dosimetry using TLD elements at PNC

    International Nuclear Information System (INIS)

    Ishiguro, Hideharu

    1985-01-01

    The evaluation method of neutron dose equivalent was studied on the basis of the albedo type neutron dosimetory to design the personnel dosimeter. The dosimeter was composed of three 6 Li 2 10 B 4 O 7 (Cu) TL elements and one 7 Li 2 11 B 4 O 7 (Cu) element. The equations for assessing thermal, epithermal and fast neutron dose equivalents were derived by 252 Cf, 241 Am-Be and PuO 2 neutron sources. The minimum detectable amount of 6 Li 2 10 B 4 O 7 (Cu) element to thermal neutron was 0.02 m rem. The neutron dose equivalent and the gamma one were evaluated separately within about 20 % error in the mixed radiation field. (author)

  8. Blind test results - measure of incessant progress in personnel monitoring services at Kudankulam Nuclear Power Project

    International Nuclear Information System (INIS)

    Jashi, K.B.; Ashok Kumar, A.; Pandaram, P.

    2018-01-01

    Personnel Monitoring Services (PMS) at Thermoluminescent Dosimeter (TLD) laboratory, Kudankulam Nuclear Power Project (KKNPP) involve monitoring of about 1500 radiation workers of KKNPP for external radiation exposure on monthly basis. Quality assurance in PMS provides an overall estimate of accuracy which depends not only upon the dosimeter quality and reader performance but also on data interpretation, applicable software and the system. Therefore it measures the effectiveness of quality control mechanism. Blind test is an effective tool to check the performance of the processor without their knowledge during routine processing of the service cards

  9. Studies on an automated gain stabilisation for the new APD read-out of the crystal barrel calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Pauli, Peter [HISKP Bonn (Germany); Collaboration: CBELSA/TAPS-Collaboration

    2016-07-01

    For the investigation of the nucleon spectrum it is not enough to measure only cross sections because of the large overlap of resonances. To disentangle these resonances, a partial wave analysis is needed. To find unambiguous solutions it is necessary to measure (double) polarisation observables. The CBELSA/TAPS experiment is an important tool to measure these observables in meson photoproduction off nucleons. To achieve a high efficiency in purely neutral reactions it is important to implement the main calorimeter into the first level trigger. To do so it is necessary to replace the current PIN photo diodes with new avalanche photo diodes (APDs). The new read-out is able to provide a timing signal that is fast enough to use it as a trigger while it does not impair the energy resolution of the calorimeter compared to the previous system. A drawback of APDs is their temperature dependency. To provide a stable gain throughout varying running conditions it is vital to monitor the temperature change and correct it if necessary. The poster shows an approach to ensure temperature stability where the temperature is monitored via a temperature sensitive NTC thermistor and the gain is adjusted via changes of the high voltage supply of the APDs. This method proved successful while it is easy to implement in all 1320 CsI(Tl) crystals of the calorimeter.

  10. IAEA reference dosimeter: Alanine-ESR

    International Nuclear Information System (INIS)

    Mehta, K.; Girzikowsky, R.

    1999-01-01

    Since 1985, the IAEA has been using alanine-ESR as a transfer dosimeter for its dose quality audit service, namely the International Dose Assurance Service. The alanine dosimeters are rod-type containing 70 wt% DL--α-alanine and 30 wt% polystyrene. We have two self-shielded gamma facilities for the calibration of the dosimetry system, where the temperature within the irradiation chamber can be controlled by a specially designed unit. A 4th order polynomial is fitted to the 16 data points in the dose range of 100 Gy to 50 kGy. The measured value of the irradiation temperature coefficient at two dose values (15 and 45 kGy) is 0.23 %/deg. C. Also, the ESR-response was followed for several dosimeters for about 8 months to study the post-irradiation effect. A value of 0.008 %/day was observed for the fading of the response for two dose values (15 and 45 kGy) and three irradiation temperatures (15, 27 and 40 deg. C). The effect of the analysis temperature on the ESR response was also studied. The combined relative uncertainty for the IAEA alanine-ESR dosimetry system is 1.5% (k=1). This includes that transferred from the primary laboratory for the dose rate measurements of the gamma facilities, dosimetry system calibration uncertainties, batch variability and uncertainty in the curve fitting procedure. This value however does not include the contribution due to the irradiation temperature correction which is applied when it differs from that during calibration; this component being specific for each dose measurement. (author)

  11. Acceptance Testing of Thermoluminescent Dosimeter Holders.

    Science.gov (United States)

    Romanyukha, Alexander; Grypp, Matthew D; Sharp, Thad J; DiRito, John N; Nelson, Martin E; Mavrogianis, Stanley T; Torres, Jeancarlo; Benevides, Luis A

    2018-05-01

    The U.S. Navy uses the Harshaw 8840/8841 dosimetric (DT-702/PD) system, which employs LiF:Mg,Cu,P thermoluminescent dosimeters (TLDs), developed and produced by Thermo Fisher Scientific (TFS). The dosimeter consists of four LiF:Mg,Cu,P elements, mounted in Teflon® on an aluminum card and placed in a plastic holder. The holder contains a unique filter for each chip made of copper, acrylonitrile butadiene styrene (ABS), Mylar®, and tin. For accredited dosimetry labs, the ISO/IEC 17025:2005(E) requires an acceptance procedure for all new equipment. The Naval Dosimetry Center (NDC) has developed and tested a new non-destructive procedure, which enables the verification and the evaluation of embedded filters in the holders. Testing is based on attenuation measurements of low-energy radiation transmitted through each filter in a representative sample group of holders to verify that the correct filter type and thickness are present. The measured response ratios are then compared with the expected response ratios. In addition, each element's measured response is compared to the mean response of the group. The test was designed and tested to identify significant nonconformities, such as missing copper or tin filters, double copper or double tin filters, or other nonconformities that may impact TLD response ratios. During the implementation of the developed procedure, testing revealed a holder with a double copper filter. To complete the evaluation, the impact of the nonconformities on proficiency testing was examined. The evaluation revealed failures in proficiency testing categories III and IV when these dosimeters were irradiated to high-energy betas.

  12. Evaluation of fading factor and self-dose for glass dosimeter and thermoluminescence dosimeter

    International Nuclear Information System (INIS)

    Yamasaki, T.; Yamanishi, H.; Miyake, H.; Komura, K.

    2000-01-01

    The glass dosimeter (GD) and thermoluminescence dosimeter (TLD) are both passive radiation detectors. They are often used for measuring environmental radiation. In order to measure low dose rate preciously, it is important to evaluate decreased dose due to fading and self-dose during the exposure period. We evaluate the fading factor and self-dose of thee passive detectors, GD and TLD. We select Ogoya tunnel for the experiment. The tunnel is suitable field for measuring faded dose and self-dose because it is low cosmic radiation. At the center of the tunnel, the intensity of cosmic ray is reduced to about 1/177 than the outside of the funnel. We prepared two sets of dosimeters. One set consists of five GDs, five TLDs and some pre-irradiated GDs and TLDs that are exposed to standard radiation of 4 mGy by Cs-137. These dosimeters are put in the 10 cm thick lead box in order to shield the terrestrial gamma ray. One set is located at the center of the tunnel and the other is the outside of the funnel. The dosimeters were exposed for ten months, from May 1998 to March 1999. After the exposure, the readers of dosimeters are carried into the funnel to read out the signals promptly as soon as taking out the dosimeters. As a result of the measurement, four kinds of data are taken for GD and TLD respectively. Assumed that the self-dose and cosmic ray are constant during exposure, the four independent unknown quantities, a self-dose a dose due to cosmic ray and a fading coefficient at the center of the tunnel and at the outside, are considered. Therefore four simultaneous equations should be obtained. From these examinations, the faded dose of GD is less than 1%, but that of TLD is about 16% during ten months. The coefficient for compensation of fading of GD and TLD is given as the half of the each value. At the outside of the tunnel, the measured dose rate of cosmic ray that can pass through the 10 cm lead is evaluated to be about 16 nGy/h by both detectors. The self

  13. Report on the Personnel Dosimetry at AB Atomenergi during 1964

    International Nuclear Information System (INIS)

    Edvardsson, K.A.; Hagsgaard, S.

    1966-01-01

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1964. No doses exceeding the recommendations of ICRP were reported. The sum of the reported external total body doses during the year was for AB Atomenergi 51.5 manrem which, distributed over the whole company personnel, corresponds to an average dose of about 35 mrem per year and person or less than 1 % of the maximum permissible dose. 31,400 gamma films and 5,800 neutron films were evaluated. The films were changed every month. Urine analyses numbered 2,731 and whole body measurements 485. A comparison is made between dose distributions at AB Atomenergi and at institutions in other countries. The fraction of all personnel carrying dosimeters and exposed to more than a nominal dose seems generally to have been less than 10-20 %

  14. Report on the Personnel Dosimetry at AB Atomenergi during 1964

    Energy Technology Data Exchange (ETDEWEB)

    Edvardsson, K A; Hagsgaard, S

    1966-01-15

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1964. No doses exceeding the recommendations of ICRP were reported. The sum of the reported external total body doses during the year was for AB Atomenergi 51.5 manrem which, distributed over the whole company personnel, corresponds to an average dose of about 35 mrem per year and person or less than 1 % of the maximum permissible dose. 31,400 gamma films and 5,800 neutron films were evaluated. The films were changed every month. Urine analyses numbered 2,731 and whole body measurements 485. A comparison is made between dose distributions at AB Atomenergi and at institutions in other countries. The fraction of all personnel carrying dosimeters and exposed to more than a nominal dose seems generally to have been less than 10-20 %.

  15. Personnel Monitoring Department - DEMIN

    International Nuclear Information System (INIS)

    1989-01-01

    The activities and purposes of the Personnel Monitoring Dept. of the Institute of Radioprotection and Dosimetry of the Brazilian CNEN are presented. A summary of the personnel monitoring service is given, such as dosemeters supply, laboratorial inspections, and so on. The programs of working, publishing, courses and personnel interchange are also presented. (J.A.M.M.)

  16. Wallac automatic alarm dosimeter type RAD21

    International Nuclear Information System (INIS)

    Burgess, P. H.; Iles, W.J.

    1980-02-01

    The Automatic Alarm Dosimeter type RAD 21 is a batterypowered personal dosemeter and exposure rate alarm monitor, designed to be worn on the body, covering an exposure range from 0.1 to 999.9 mR and has an audible alarm which can be pre-set over the range 1 mR h -1 to 250 mR h -1 . The instrument is designed to measure x- and γ radiation over the energy range 50 keV to 3 MeV. The facilities and controls, the radiation, electrical, environmental and mechanical characteristics, and the manual, have been evaluated. (U.K.)

  17. Eleventh DOE workshop on personnel neutron dosimetry

    International Nuclear Information System (INIS)

    1991-01-01

    Since its formation, the Office of Health (EH-40) has stressed the importance of the exchange of information related to and improvements in neutron dosimetry. This Workshop was the eleventh in the series sponsored by the Department of Energy (DOE). It provided a forum for operational personnel at DOE facilities to discuss current issues related to neutron dosimetry and for leading investigators in the field to discuss promising approaches for future research. A total of 26 papers were presented including the keynote address by Dr. Warren K. Sinclair, who spoke on, ''The 1990 Recommendations of the ICRP and their Biological Background.'' The first several papers discussed difficulties in measuring neutrons of different energies and ways of compensating or deriving correction factors at individual facilities. Presentations were also given by the US Navy and Air Force. Current research in neutron dosimeter development was the subject of the largest number of papers. These included a number on the development of neutron spectrometers

  18. Nuclear radiation monitoring instruments for personnel in nuclear disaster for defence needs

    International Nuclear Information System (INIS)

    Bhatnagar, P.K.; Vaijapurkar, S.G.; Yadav, Ashok

    2005-01-01

    Ever since the tragedy of nuclear device exploding over Japan by USA in 1945 awareness exists amongst the armed forces personnel all over the world that a requirement of implementing radiological protection is imminent. Towards this adoption of radiological safety programme is a criterion. In a nuclear war disaster scenario, one encounters initial nuclear radiation (gamma and neutron radiations), gamma radiations from fallout, heat and blast. At certain distances Tanks/ armoured vehicles will survive and 4 R/s radiation level sensing to actuate relays for closing the ports of vehicles is essential, leading to reduction in inhalation, ingestion of fallout radioactivity and reduction in radiation dose received by occupants of the vehicle. Towards this sturdy radiation monitors to indicate gamma dose rate of the order of 1000 R/h, gamma and neutron dosimeters of the order of 1000 cGy with reading instruments are to be developed. These must work in harsh environment and sustain JSS 55555 conditions of army. Defence Laboratory, Jodhpur over past one decade has been involved in developing personnel, area and field monitoring instruments like dosimeters, survey meters, which are useful, acceptable to army personnel, armoured and personnel carrier vehicles, field structures/shelters. Technology transfer after satisfaction of armed forces, product ionisation and supply, maintenance, training has been the endeavor of the DRDO. Herein it is proposed to highlight the techno electronics nuclear radiation monitoring sensors and associated electronics systems developed first time in the country and productionised in bulk for Services for implementing personnel protection. The sensors developed and described are - Radiophotoluminescent Glass (RPLG) for gamma radiation dosimetry , neutron sensitive PIN diode for fast neutron dosimetry, gamma radiation sensitive PIN diode, superheated liquid neutron and gamma sensors. The dosimeter, dose rate meter and field/area instruments are

  19. Personnel preferences in personnel planning and scheduling

    OpenAIRE

    van der Veen, Egbert

    2013-01-01

    Summary The personnel of an organization often has two conflicting goals. Individual employees like to have a good work-life balance, by having personal preferences taken into account, whereas there is also the common goal to work efficiently. By applying techniques and methods from Operations Research, a subfield of applied mathematics, we show that operational efficiency can be achieved while taking personnel preferences into account. In the design of optimization methods, we explicitly con...

  20. Liquid polymers for using in a holographic ionizing radiation dosimeter

    International Nuclear Information System (INIS)

    Nicolau-Rebigan, S.

    1979-01-01

    Some liquid polymeric systems for using in the holographic ionizing radiation dosimeter are presented. It is shown that the action of radiation on polymers leads to the destruction of the polymeric chains or to perform them, the both processes being applied in radiation dosimetry. Some advantages of the holographic dosimeter are outlined comparatively with those common used. (author)

  1. Assessment of Siemens plessey electronic personal dosimeter

    International Nuclear Information System (INIS)

    Hirning, C.R.; Lopez, S.; Yuen, P.S.

    1994-01-01

    This report presents the results of a laboratory assessment of the performance of a new type of personal dosimeter. The Electronic Personal Dosimeter, or EPD, was developed jointly by the National Radiological Protection Board and Siemens Plessey Controls Limited, both of the United Kingdom. Twenty pre-production units of the EPD and a reader were purchased by Ontario Hydro for the assessment. The tests were conducted jointly by Ontario Hydro's Health and Safety Division and AECL Research's Chalk River Laboratories (CRL), with funding from the Candu Owner's Group. A total of 26 tests were conducted, divided between Ontario Hydro and AECL. The test results were compared with the relevant requirements of three standards. In general, the performance of the EPD was found to be quite acceptable. It met most of the relevant requirements of the three standards and most of the design specifications. However, the following deficiencies were found: slow response time; sensitivity to high-frequency EMF; poor resistance to dropping; and an alarm that is not loud enough. In addition, the response of the EPD to low-energy beta rays may be too low for some applications. There were serious problems with the reliability of operation of the pre production EPDs used in these tests. 9 refs., 34 tabs., 20 figs

  2. Assessment of Siemens plessey electronic personal dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Hirning, C R; Lopez, S [Ontario Hydro, Toronto, ON (Canada); Yuen, P S [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.

    1994-01-01

    This report presents the results of a laboratory assessment of the performance of a new type of personal dosimeter. The Electronic Personal Dosimeter, or EPD, was developed jointly by the National Radiological Protection Board and Siemens Plessey Controls Limited, both of the United Kingdom. Twenty pre-production units of the EPD and a reader were purchased by Ontario Hydro for the assessment. The tests were conducted jointly by Ontario Hydro`s Health and Safety Division and AECL Research`s Chalk River Laboratories (CRL), with funding from the Candu Owner`s Group. A total of 26 tests were conducted, divided between Ontario Hydro and AECL. The test results were compared with the relevant requirements of three standards. In general, the performance of the EPD was found to be quite acceptable. It met most of the relevant requirements of the three standards and most of the design specifications. However, the following deficiencies were found: slow response time; sensitivity to high-frequency EMF; poor resistance to dropping; and an alarm that is not loud enough. In addition, the response of the EPD to low-energy beta rays may be too low for some applications. There were serious problems with the reliability of operation of the pre production EPDs used in these tests. 9 refs., 34 tabs., 20 figs.

  3. The dosimeter personal use in controlled area

    International Nuclear Information System (INIS)

    Costa, R. F.

    2015-01-01

    The discovery of X-rays revolutionized medicine because it allowed a patient to be examined internally with no surgery. But also caused damage to health professionals and patients due, its oxidizing action. In the beginning of its discovery, many doctors were exposed and exposed beams to their patients for long periods of time, therefore, they developed diseases caused by radiation and the medical community realized that something was wrong. Then created a radiological protection commission to regulate its use in humans and so limit your exposure. Today we know that many companies still did not fit the standards of radiation protection. So we evaluate the technical professionals in radiology regarding the correct use of personal dosimeter, through a descriptive study with a quantitative approach, we used the information collection technique based on a questionnaire developed for this purpose which was delivered and collected personally. From this survey, we sought to assess the knowledge of the basic guidelines of radiological protection. He concluded that the majority of respondents know the rules of use of the personal dosimeter, but do not use it properly, due mainly to lack of supervision by the company, overwork and neglect. (author)

  4. Laser readable thermoluminescent radiation dosimeters and methods for producing thereof

    International Nuclear Information System (INIS)

    Braunlich, P.F.; Tetzlaff, W.

    1989-01-01

    Thin layer thermoluminescent radiation dosimeters for use in laser readable dosimetry systems, and methods of fabricating such thin layer dosimeters are disclosed. The thin layer thermoluminescent radiation dosimeters include a thin substrate made from glass or other inorganic materials capable of withstanding high temperatures and high heating rates. A thin layer of a thermoluminescent phosphor material is heat bonded to the substrate using an inorganic binder such as glass. The dosimeters can be mounted in frames and cases for ease in handling. Methods of the invention include mixing a suitable phosphor composition and binder, both being in particulate or granular form. The mixture is then deposited onto a substrate such as by using mask printing techniques. The dosimeters are thereafter heated to fuse and bond the binder and phosphor to the substrate. 34 figs

  5. Reactor Gamma Heat Measurements with Calorimeters and Thermoluminescence Dosimeters

    DEFF Research Database (Denmark)

    Haack, Karsten; Majborn, Benny

    1973-01-01

    Intercomparison measurements of reactor γ-ray heating were carried out with calorimeters and thermoluminescence dosimeters. Within the measurement uncertainties the two methods yield coincident results. In the actual measurement range thermoluminescence dosimeters are less accurate than calorimet......Intercomparison measurements of reactor γ-ray heating were carried out with calorimeters and thermoluminescence dosimeters. Within the measurement uncertainties the two methods yield coincident results. In the actual measurement range thermoluminescence dosimeters are less accurate than...... calorimeters, but possess advantages such as a small probe size and the possibility of making simultaneous measurements at many different positions. Hence, thermoluminescence dosimeters may constitute a valuable supplement to calorimeters for reactor γ-ray heating measurements....

  6. Advances in the development of Cr-39 based neutron dosimeters

    International Nuclear Information System (INIS)

    Hadlock, D.E.; Parkhurst, M.A.

    1987-12-01

    A combination thermoluminescent dosimeter (TLD) and track etch dosimeter (TED), which can be used for detecting neutrons over a wide energy range, has been developed through recent research in passive neutron dosimetery. This dosimeter uses Li-600 TLDs to detect thermal and low energy neutrons reflected from the body, and the TED polymer of CR-39, to detect fast neutrons from proton recoil interactions with the polyethylene radiator or with CR-39 itself. Some form of the combination dosimeter is currently in use at several US Department of Energy (DOE) facilities, and its use is expected to expand over the next year to include all DOE facilities where significant neutron exposures may occur. The extensive research conducted on the TED component over the past six years has continually focused on material improvements, reduction in processing time and dosimeter handling, and ease of sample readout with the goal of automating the process as much as possible. 1 fig

  7. Temperature dependence of gafchromic MD-55 dosimeter

    International Nuclear Information System (INIS)

    Klassen, Norman V.; Zwan, Len van der; Cygler, Joanna

    1997-01-01

    Objective: Gafchromic MD-55 is a fairly new, thin film dosimeter that develops a blue color (λ max = 676 nm) when irradiated with ionizing radiation. The increase in absorbance is nearly proportional to the absorbed dose. MD-55 can be used for high precision dosimetry if care is taken to assure reproducible film orientation in the spectrophotometer as well as temperature control during both irradiation and reading. In order to achieve the maximum sensitivity of this dosimeter the readings of the optical density should be taken at λ max . It was reported for another type of Gafchromic film (DM-1260), that both λ max and ε max decrease with an increase in the temperature of the spectrophotometer. The purpose of this study was to characterize the reading temperature dependence of the new type of Gafchromic film available on the market and to find optimal conditions for using it for high precision dosimetry. Materials and Methods: Irradiations were carried out using 60 Co gamma rays from an Eldorado irradiator. The dosimeters were sandwiched in a lucite phantom with 4.4 mm build-up and irradiated in the center of a 10 cm x 10 cm field at 1 meter from the source. The temperature during irradiations was 22 deg. C. The dose rate was about 0.68 Gy/min. Measurements of optical density were made using a Cary 210 spectrophotometer. A bandpass of 3.5 nm was used. The temperature of the baseplate of the sample holder was regulated to +/-0.05 deg. C and measured by a probe lying on the baseplate. In all cases, values of OD were only recorded after they had come to a constant value, which was reached within 5 minutes of inserting the dosimeter into the sample chamber of the spectrophotometer. Results: The temperature dependence of the OD at 676 nm was measured in 2 studies using 6 dosimeters that had received 0, 1.0, 3.5, 6.2, 14.5 Gy. Readings were taken at 7 temperatures between 18.8 and 28.1 deg. C. By returning to the initial temperature several hours later, it was found

  8. Fast fluence measurement for JOYO irradiation field using niobium dosimeter

    International Nuclear Information System (INIS)

    Ito, Chikara

    2004-03-01

    Neutron fluence and spectrum are key parameters in various irradiation tests and material surveillance tests so they need to be evaluated accurately. The reactor dosimetry test has been conducted by the multiple foil activation method, and a niobium dosimeter has been developed for measurement of fast neutron fluence in the experimental fast reactor JOYO. The inelastic scattering reaction of 93 Nb has a low threshold energy, about 30 keV, and the energy distribution of reaction cross section is similar to the displacement cross section for iron. Therefore, a niobium dosimeter is suitable for evaluation of the fast neutron fluence and the displacement per atom for iron. Moreover, a niobium dosimeter is suited to measure neutron fluence in long-term irradiation test because 93 Nb, which is produced by the reaction, has a long half-life (16.4 years). This study established a high precision measurement technique using the niobium reaction rate. The effect of self-absorption was decreased by the solution and evaporation to dryness of niobium dosimeter. The dosimeter weight was precisely measured using the inductively coupled plasma mass spectrometer. This technique was applied to JOYO dosimetry. The fast neutron fluences (E > 0.1 MeV) found by measuring the reaction rate in the niobium dosimeter were compared with the values evaluated using the multiple foil activation method. The ratio of measured fast neutron fluences by means of niobium dosimeter and multiple foil activation method range from 0.97 to 1.03 and agree within the experimental uncertainty. The measurement errors of fast neutron fluence by niobium dosimeter range from 4.5% (fuel region) to 10.1% (in-vessel storage rack). As a result of this study, the high precision measurement of fast neutron fluence by niobium dosimeters was confirmed. The accuracy of fast reactor dosimetry will be improved by application of niobium dosimeters to the irradiation tests in the JOYO MK-III core. (author)

  9. Cytogenetic diagnostic of 3 populations of occupationally exposed personnel

    International Nuclear Information System (INIS)

    Guerrero C, C.; Arceo M, C.

    2013-10-01

    In the year 2000 the first service of biological dosimetry was requested to the Instituto Nacional de Investigaciones Nucleares (ININ), and until the year 2012 have been assisted 52 cases approximately. Most of the cases correspond to workers dedicated to the industrial radiography, followed by the occupationally exposed personnel either in the hospital area or health services and the minority corresponds to individuals linked to research institutions. The incident with more serious consequences to the individual happened to workers that ingested I-131 in the year 2003. Using the biological dosimetry to estimate exposure dose by damage in the lymphocyte chromosomes of each worker has been possible to establish the exposure dose in each one of them, or also to discard the supposed exposure. The dosimetry demonstrates to be an useful tool for situations with exposure suspicion, for example when the reading of thermoluminescent dosimeter of a occupationally exposed personnel does not correspond to the event, or when the personnel forgets to carry his dosimeter, the exposure dose can be determined. (Author)

  10. The Martin Marietta Energy Systems personnel neutron dosimetry program

    International Nuclear Information System (INIS)

    McMahan, K.L.

    1991-01-01

    Martin Marietta Energy Systems, Inc. (Energy Systems), manages five sites for the US Department of Energy. Personnel dosimetry for four of the five sites is coordinated through a Centralized External Dosimetry System (CEDS). These four sites are the Oak Ridge National Laboratory (ORNL), the Oak Ridge Y-12 Plant (Y-12), the Oak Ridge K-25 Site (K-25), and the Paducah Gaseous Diffusion Plant (PGDP). The fifth Energy Systems site, Portsmouth Gaseous Diffusion Plant, has an independent personnel dosimetry program. The current CEDS personnel neutron dosimeter was first issued in January 1989, after an evaluation and characterization of the dosimeters' response in the workplaces was performed. For the workplace characterization, Energy Systems contracted with Pacific Northwest Laboratory (PNL) to perform neutron measurements at selected locations at ORNL and Y-12. K-25 and PGDP were not included because their neutron radiation fields were similar to others already planned for characterization at ORNL and Y-12. Since the initial characterization, PNL has returned to Oak Ridge twice to perform follow up measurements, and another visit is planned in the near future

  11. Luminescence studies of rare earth doped dosimeters

    International Nuclear Information System (INIS)

    Karali, T.

    1999-10-01

    The main objective of this thesis has been to address the applications and fundamentals of thermoluminescence (TL) and to contribute to existing knowledge about TL mechanisms in materials which are applied as radiation dosimeters. This issue has been explored for a long time but the mechanisms lack completeness and certainty. TL, Radioluminescence (RL) and Radio-thermoluminescence (RLTL) measurements have been conducted on a high sensitivity TL spectrometer both at low (30-290 K) and high (25-400 deg. C) temperatures, and different heat treatments (furnace and laser) were conducted in order to study the possible impurity clustering which changes the TL spectra and efficiency of the dosimeters. Studies have been based on three different host structure, namely sulphate, borates and zircon. The spectra of calcium sulphate samples doped with Tm 3+ and Dy 3+ at different concentration were examined using TL, RL and RLTL. Similar procedures were applied to the borate samples. Modifications of the material by thermal treatments convert the state of dispersion of the rare earth ions between isolated, pair or defect clusters, which alter the dosimeter efficiency. In some cases, modified geometries are detectable by movement of the line emissions such as for quenched samples which are attributable to new microcrystal line phases. The study of co-doped samples showed unequivocal evidence of a glow peak displacement of the two dopants within a single sample. This result supports the new view that RE 3+ ions could form part of a complex defect acting as both charge trap and recombination centres. Pulsed laser heating with a UV laser changed the glow curve shape and lead to strong signals. The detailed mechanisms for this process are discussed. The RL and TL spectra of synthetic zircon crystals doped with different RE 3+ ions (Pr, Sm, Eu, Gd, Ho, Dy, Er, and Yb) and phosphorus are reported. Even though there is some intrinsic emission from the host lattice the major signals are

  12. Radiation doses to personnel in clinics for gynecologic oncology

    International Nuclear Information System (INIS)

    Forsberg, B.; Spanne, P.

    1985-01-01

    Radium or Cesium is used for radiotherapy of gynecologic cancer at six clinics in Sweden. This report gives a survey of the radiation doses the personnel is exposed to. The measurement were performed using TL-dosimeters. The dose equivalents for different parts of the body at specific working moments was deduced as well as the effective dose equivalent and the collective dose equivalent. 1983 the total collective dose equivalent for the six clinics was 1.3 manSv, which corresponds to 3.9 manmSv/g equivalent mass of Radium used at the treatments. (With 11 tables and 10 figures) (L.E.)

  13. An approved personal dosimetry service based on an electronic dosimeter

    International Nuclear Information System (INIS)

    Marshall, T.O.; Bartlett, D.T.; Burgess, P.H.; Campbell, J.I.; Hill, C.E.; Pook, E.A.; Sandford, D.J.

    1991-01-01

    At the Second Conference on Radiation Protection and Dosimetry a paper was presented which, in part, announced the development of an electronic dosimeter to be undertaken in the UK by the National Radiological Protection Board (NRPB) and Siemens Plessey Controls Ltd. This dosimeter was to be of a standard suitable for use as the basis of an approved personal dosimetry service for photon and beta radiations. The project has progressed extremely well and dosimeters and readers are about to become commercially available. The system and the specification of the dosimeter are presented. The NRPB is in the process of applying for approval by the Health and Safety Executive (HSE) to operate as personal monitoring service based on this dosimeter. As part of the approval procedure the dosimeter is being type tested and is also undergoing an HSE performance test and wearer trials. The tests and the wearer trials are described and a summary of the results to date presented. The way in which the service will be organized and operated is described and a comparison is made between the running of the service and others based on passive dosimeters at NRPB

  14. Light scattering in optical CT scanning of Presage dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y; Adamovics, J; Cheeseborough, J C; Chao, K S; Wuu, C S, E-mail: yx2010@columbia.ed

    2010-11-01

    The intensity of the scattered light from the Presage dosimeters was measured using a Thorlabs PM100D optical power meter (Thorlabs Inc, Newton, NJ) with an optical sensor of 1 mm diameter sensitive area. Five Presage dosimeters were made as cylinders of 15.2 cm, 10 cm, 4 cm diameters and irradiated with 6 MV photons using a Varian Clinac 2100EX. Each dosimeter was put into the scanning tank of an OCTOPUS' optical CT scanner (MGS Research Inc, Madison, CT) filled with a refractive index matching liquid. A laser diode was positioned at one side of the water tank to generate a stationary laser beam of 0.8 mm width. On the other side of the tank, an in-house manufactured positioning system was used to move the optical sensor in the direction perpendicular to the outgoing laser beam from the dosimeters at an increment of 1 mm. The amount of scattered photons was found to be more than 1% of the primary light signal within 2 mm from the laser beam but decreases sharply with increasing off-axis distance. The intensity of the scattered light increases with increasing light attenuations and/or absorptions in the dosimeters. The scattered light at the same off-axis distance was weaker for dosimeters of larger diameters and for larger detector-to-dosimeter distances. Methods for minimizing the effect of the light scattering in different types of optical CT scanners are discussed.

  15. Water-resistant alanine-EPR dosimeter alanpol

    International Nuclear Information System (INIS)

    Peimel-Stuglik, Zofia; Bryl-Sandelewska, Teresa; Mirkowski, Krzysztof; Sartowska, Bozena

    2009-01-01

    Alanpol-water-resistant alanine-electron paramagnetic resonance (EPR) dosimeter consisted of cheap DL-α-alanine (9.8-27%) suspended in polyethylene matrix was presented. The rods (O=2.8 mm) were extruded from a hot mixture of alanine and low-density polyethylene. No grinding or crushing was used for alanine preparation. An orientation of cylindrical crystals, up to 300 μm long in parallel to the rod axis was responsible for some differences in a shape of EPR signal. These differences had no negative consequences for dosimetric applications. Signal-to-dose dependence was linear up to 10 kGy. Standard deviation of dosimetric answer was up to ±1.8% and up to 2.4% for dosimeters with 9.8% and 27% of DL-α-alanine, respectively. Irradiation temperature coefficient for both dosimeters was equal 0.2%/ deg. C. Hydrophobic properties of polyethylene and small number of alanine crystals located on the surface of the rod led to high resistance of dosimeters to water and humidity. The 24 h soaking of irradiated dosimeters in liquid water-reduced EPR signals by 3-4% and by 2-3% for dosimeters with 27% and 9.8% of DL-α-alanine, respectively. Three month storage time of irradiated dosimeters in room conditions decreases EPR signal for ∼3%.

  16. Investigating On Colour Stability Conditions Of Postirradiation Radiochromic Film Dosimeter

    International Nuclear Information System (INIS)

    Nguyen Nguyet Dieu; Doan Binh; Pham Thu Hong; Cao Van Chung; Nguyen Thanh Duoc

    2011-01-01

    B3 dosimeter is a thin film with average thickness of 0.0194 mm, which is supplied by the Gex company, the United States. This dosimeter was influenced by many factors: light, temperature, humidity during and after irradiation process. In fact, B3 film dosimeters will be stable under certain conditions such as tightly sealed packs, controlled irradiation and stored temperature after irradiated. Therefore, investigation of the stability effect of postirradiated B3 film dosimeters on the heating temperature, heating time and storing time is carried out before the absorbed dose is read and followed standard reading procedures. When exposed to ionizing radiation, the dosimeters change from colorless to colour. The absorbed doses are read on a Genesys 20 spectrophotometer at a wavelength of 544 nm. Absorbed dose range is investigated from 0.55 to 80 kGy. Experimental results were indicated that colour stability of the postirradiated dosimeters at a temperature of 65 ± 3 o C for 30 minutes and keeping them in desiccator for 5 minutes before read out. Under these conditions, colour stability of B3 film dosimeter has maintained for 3 months. (author)

  17. New Generation of self-calibrated SS/EPR dosimeters: Alanine/EPR dosimeters

    International Nuclear Information System (INIS)

    Yordanov, N.D.; Gancheva, V.

    1999-01-01

    A new type of solid state/EPR dosimeters is described. Principally, it contains radiation sensitive diamagnetic material, some quantity of EPR active, but radiation insensitive, substance (for example Mn 2+ /MgO) and a binding material. In the present case alanine is used as a radiation sensitive substance. With this dosimeter, the EPR spectra of alanine and Mn 2+ are simultaneously recorded and the calibration graph represents the ratio of alanine versus Mn 2+ EPR signal intensity as a function of absorbed dose. In this way the reproducibility of the results is expected to be improved significantly including their intercomparison among different laboratories. Homogeneity of the prepared dosimeters and their behaviour (fading of EPR signals with time, influence of different meteorological conditions) show satisfactory reproducibility and stability with time. Because two different EPR active samples are recorded simultaneously, the influence of some instrument setting parameters (microwave power, modulation amplitude and modulation frequency) on the ratio I alanine /I Mn is also investigated. (author)

  18. p-MOSFET total dose dosimeter

    Science.gov (United States)

    Buehler, Martin G. (Inventor); Blaes, Brent R. (Inventor)

    1994-01-01

    A p-MOSFET total dose dosimeter where the gate voltage is proportional to the incident radiation dose. It is configured in an n-WELL of a p-BODY substrate. It is operated in the saturation region which is ensured by connecting the gate to the drain. The n-well is connected to zero bias. Current flow from source to drain, rather than from peripheral leakage, is ensured by configuring the device as an edgeless MOSFET where the source completely surrounds the drain. The drain junction is the only junction not connected to zero bias. The MOSFET is connected as part of the feedback loop of an operational amplifier. The operational amplifier holds the drain current fixed at a level which minimizes temperature dependence and also fixes the drain voltage. The sensitivity to radiation is made maximum by operating the MOSFET in the OFF state during radiation soak.

  19. Study of an individual neutron dosimeter

    International Nuclear Information System (INIS)

    Debeauvais, M.; Tripier, J.

    1976-01-01

    A dosimeter using Kodak LR 115 cellulose nitrate as detecting material was designed. It serves to determine 3 neutron energy ranges. The 6 Li(n,α)t reaction is used for the thermal region, the sensitivity being 0.2mrads to 1 rad for neutron energies between thermal and 0.05eV. The same reaction defines the 0.05eV to 1000eV energy range but the detection system is placed inside a cadmium screen; the sensitivity is 0.2 to 500rads. Finally above 1MeV the neutron reactions used are those on the detector components themselves, i.e. elastic collisions and (nα) reactions on carbon, nitrogen and oxygen nuclei. Detection is possible between 0.7 and 700 rads [fr

  20. SU-E-T-749: Thorough Calibration of MOSFET Dosimeters

    International Nuclear Information System (INIS)

    Plenkovich, D; Thomas, J

    2015-01-01

    Purpose: To improve the accuracy of the MOSFET calibration procedure by performing the measurement several times and calculating the average value of the calibration factor for various photon and electron energies. Methods: The output of three photon and six electron beams of Varian Trilogy linear accelerator SN 5878 was calibrated. Five reinforced standard sensitivity MOSFET dosimeters were placed in the calibration jig and connected to the Reader Module. As the backscatter material was used 7 cm of Virtual Water. The MOSFET dosimeters were covered with 1.5 cm thick bolus for the regular and SRS 6 MV beams, 3 cm bolus for 15 MV beam, 1.5 cm bolus for 6 MeV electron beam, and 2 cm bolus for the electron energies of 9, 12, 15, 18, and 22 MeV. The dosimeters were exposed to 100 MU, and the calibration factor was determined using the mobileMOSFET software. To improve the accuracy of calibration, this procedure was repeated ten times and the calibration factors were averaged. Results: As the number of calibrations was increasing the variability of calibration factors of different dosimeters was decreasing. After ten calibrations, the calibration factors for all five dosimeters were within 1% of one another for all energies, except 6 MV SRS photons and 6 MeV electrons, for which the variability was 2%. Conclusions: The described process results in calibration factors which are almost independent of modality or energy. Once calibrated, the dosimeters may be used for in-vivo dosimetry or for daily verification of the beam output. Measurement of the radiation dose under bolus and scatter to the eye are examples of frequent use of calibrated MOSFET dosimeters. The calibration factor determined for full build-up is used under these circumstances. To the best of our knowledge, such thorough procedure for calibrating MOSFET dosimeters has not been reported previously. Best Medical Canada provided MOSFET dosimeters for this project

  1. Organic liquids as ''activ media'' in a holographic ionizing radiation dosimeter

    International Nuclear Information System (INIS)

    Nicolau-Rebigan, S.

    1979-01-01

    Some types of organic liquids for using as activ media in a holographic ionizing radiation dosimeter are presented. One outlined the advantages of the holographic dosimeter comparatively with those of common used dosimeters. One presented the advantages of utilization of the organic liquids comparatively with another chemical systems used in a holographic ionizing radiation dosimeter. (author)

  2. Study and realization of pixelated APD Geiger photodetectors of very high sensitivity for Very High Energy gamma astronomy

    International Nuclear Information System (INIS)

    Jradi, K.

    2010-07-01

    Very High Energy gamma ray astronomy uses till now exclusively as detector the Photomultiplier Tube (PMT) to collect weak light flux of atmospheric showers. But an alternative is now emerging: Avalanche Photodiodes polarized in Geiger mode called 'Geiger-APD'. The PMT is a detector designed in the 70's which presents many advantages but also suffers from several drawbacks: size, weight, cost, sensitivity to magnetic field but especially difficulty to realize its pixelation in matrix. Geiger-APDs are semi-conductor devices made of PN junction integrated in a special technology to detect very low light flux, thanks to the polarization beyond the avalanche voltage. Geiger-APD presents very high photoelectron gain (∼106) strongly dependant on the polarization voltage beyond avalanche. These photodiodes present many advantages with respect to PMT, mainly as concerns miniaturization for applications based on imaging, such as the detection of Cerenkov flashes in gamma ray astronomy. In this thesis, we present the study, the design and the realization of a technological structure, based on Silicon. This structure has shown reliability to detect weak luminous flux with breakdown voltage at 12 V and dark current below 10 pA at breakdown. We also developed several models, physical and electrical, necessary to the technological optimization, as well to the development of control and readout circuits, i.e. the basis of any imaging technology. The work presented here consists in the study, the design and the realization of a matrix of high sensitivity pixels. A project of a Cerenkov telescope based on this innovative technology is also presented. (author)

  3. Design of calibration method in neutron and individual dosimeter

    International Nuclear Information System (INIS)

    Belkhodia, M.

    1984-12-01

    Usually albedo dosemeters are calibrated with beam of monoenergetic neutrons. Since neutron energy around neutron sources varies greatly, we applied the calibration method to a mixed field whose energy spectrum lies between 0.025 ev and 10 Mev. The method is based on a mathematical model that deals with the dosimeter response as a function at the neutron energy. The measurements carried out with solid state nuclear track detectors show the dosimeter practical aspect. The albedo dosimeter calibration gave results on good agreement with the international institution recommendations

  4. Development of a new type thyroid glands dosimeter

    International Nuclear Information System (INIS)

    He Lihua; Song Yiyang; Chen Qin; Chen Yannan

    2000-01-01

    A new dosimeter of 125 I in thyroid gland is described. The dosimeter consists of NaI(Tl) detector and intelligent data recorder. Single-chip-microcomputer is used for data handling. The activity of 125 I in thyroid glands of human being is measured directly, rapidly, and accurately. Furthermore, it can calculate and display the intake, committed dose equivalent and committed effective dose equivalent. The measuring range of 125 I in thyroid glands is 10-2 x 10 6 Bq. The dosimeter has been operating continuously for a long time with high stability

  5. Polymer gel dosimeter with AQUAJOINT® as hydrogel matrix

    Science.gov (United States)

    Maeyama, Takuya; Ishida, Yasuhiro; Kudo, Yoshihiro; Fukasaku, Kazuaki; Ishikawa, Kenichi L.; Fukunishi, Nobuhisa

    2018-05-01

    We report a polymer gel dosimeter based on a new gel matrix (AQUAJOINT®) that is a thermo-irreversible hydrogel formed by mixing two types of water-based liquids at room temperature. Normoxic N-vinylpyrrolidone-based polymer gels were prepared with AQUAJOINT® instead of gelatin. This AQUAJOINT®-based gel dosimeter exhibits a 2.5-fold increase in sensitivity over a gelatin-based gel dosimeter and a linear dose-response in the dose range of 0-8 Gy. This gel has heat resistance in a jar and controlled gel properties such as viscoelastic and mechanical characters, which may be useful for deformable polymer gel dosimetry.

  6. Environmental monitoring by CaSO4:Dy TL dosimeters

    International Nuclear Information System (INIS)

    Deme, S.; Szabo, P.P.

    1975-12-01

    The thermoluminescent dosimeters of high sensitivity are useful for monitoring the area near nuclear installations. CaSO 4 :Dy TL dosimeters have high sensitivity and low fading so that by means of them the dose from the background can be measured with an accuracy of 10-20%. An increase of 2 mR in the background can be observed and doses as high as 1000R can be registered with an accuracy of 5%. The measuring method and results are reported here. For two years these CaSO 4 :Dy dosimeters have been successfully used at the site of the Central Research Institute for Physics. (K.A.)

  7. Alanine EPR dosimeter response in proton therapy beams

    International Nuclear Information System (INIS)

    Gall, K.; Serago, C.; Desrosiers, M.; Bensen, D.

    1997-01-01

    We report a series of measurements directed to assess the suitability of alanine as a mailable dosimeter for dosimetry quality assurance of proton radiation therapy beams. These measurements include dose-response of alanine at 140 MeV, and comparison of response vs energy with a parallel plate ionization chamber. All irradiations were made at the Harvard Cyclotron Laboratory, and the dosimeters were read at NIST. The results encourage us that alanine could be expected to serve as a mailable dosimeter with systematic error due to differential energy response no greater than 3% when doses of 25 Gy are used. (Author)

  8. Investigation of self-indicating radiation personal dosimeter

    International Nuclear Information System (INIS)

    Xia Wen; Ye Honsheng; Lin Min; Xu Lijun; Chen Kesheng; Chen Yizhen

    2014-01-01

    A self-indicating radiation personal dosimeter was investigated using radiation sensitive material diacetylene monomer PCDA, which was a component of the polymerization system. The substrate material, solvent, sensitive material, solution temperature, thickness of film and the preparation method were studied. The dosimeter colour changes from white to blue when exposed 0.1-2.5 Gy, and the linearly dependent coefficient of the exposure response is 0.9998, the stability of absorbency in two weeks after exposure is testified well. It can be used as self-indicating radiation alert personal dosimeter. (authors)

  9. Device for the automatic evaluation of pencil dosimeters

    International Nuclear Information System (INIS)

    Schallopp, B.

    1976-01-01

    In connenction with the automation of radiation protection in nuclear power plants, an automatic reading device has been developed for the direct input of the readings of pencil dosimeters into a computer. Voltage measurements would be simple but are excluded, because the internal electrode of the dosimeter may not be touched, for operational reasons. This paper describes an optical/electronic conversion device in which the reading of the dosimeter is projected onto a Vidicon, scanned, and converted into a digital signal for output to the computer. (orig.) [de

  10. Performances of a HGCDTE APD based direct detection lidar at 2 μm. Application to dial measurements

    Science.gov (United States)

    Gibert, Fabien; Dumas, Arnaud; Rothman, Johan; Edouart, Dimitri; Cénac, Claire; Pellegrino, Jessica

    2018-04-01

    A lidar receiver with a direct detection chain adapted to a HgCdTe APD based detector with electric cooling is associated to a 2.05 μm Ho :YLF pulsed dual wavelength single mode transmitter to provide the first atmospheric lidar measurements using this technology. Experiments confirm the outstanding sensitivity of the detector and hightligth its huge potential for DIAL measurements of trace gas (CO2 and H2O) in this spectral domain. Performances of coherent vs direct detection at 2.05 μm is assessed.

  11. Performances of a HGCDTE APD based direct detection lidar at 2 μm. Application to dial measurements

    Directory of Open Access Journals (Sweden)

    Gibert Fabien

    2018-01-01

    Full Text Available A lidar receiver with a direct detection chain adapted to a HgCdTe APD based detector with electric cooling is associated to a 2.05 μm Ho :YLF pulsed dual wavelength single mode transmitter to provide the first atmospheric lidar measurements using this technology. Experiments confirm the outstanding sensitivity of the detector and hightligth its huge potential for DIAL measurements of trace gas (CO2 and H2O in this spectral domain. Performances of coherent vs direct detection at 2.05 μm is assessed.

  12. Performances of a HGCDTE APD Based Detector with Electric Cooling for 2-μm DIAL/IPDA Applications

    Directory of Open Access Journals (Sweden)

    Dumas A.

    2016-01-01

    Full Text Available In this work we report on design and testing of an HgCdTe Avalanche Photodiode (APD detector assembly for lidar applications in the Short Wavelength Infrared Region (SWIR : 1,5 - 2 μm. This detector consists in a set of diodes set in parallel -making a 200 μm large sensitive area- and connected to a custom high gain TransImpedance Amplifier (TIA. A commercial four stages Peltier cooler is used to reach an operating temperature of 185K. Crucial performances for lidar use are investigated : linearity, dynamic range, spatial homogeneity, noise and resistance to intense illumination.

  13. Study of a pure CsI crystal readout by APD for Belle II end cap ECL upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Y., E-mail: jin@hep.phys.s.u-tokyo.ac.jp [Department of Physics, the University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033 (Japan); Aihara, H. [Department of Physics, the University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033 (Japan); Borshchev, O.V. [Enikolopov Institute of Synthetic Polymeric Materials of the Russian Academy of Sciences, Profsoyuznaya st. 70, Moscow 117393 (Russian Federation); Epifanov, D.A. [Department of Physics, the University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033 (Japan); Ponomarenko, S.A.; Surin, N.M. [Enikolopov Institute of Synthetic Polymeric Materials of the Russian Academy of Sciences, Profsoyuznaya st. 70, Moscow 117393 (Russian Federation)

    2016-07-11

    A scintillation counter consisting of a pure CsI crystal and avalanche photodiodes (Hamamatsu APD S8664-55 and S8664-1010) has been studied for the upgrade of the end cap electromagnetic calorimeter of Belle II detector. An essential increase of the light output was achieved with wavelength shifters based on nanostructured organosilicon luminophores. - Highlights: • A scintillation counter consisting of a pure CsI crystal and avalanche photodiodes has been studied. • The equivalent noise charge and equivalent noise energy of the counter have been measured. • An essential increase of the light output was achieved with wavelength shifters.

  14. Personal noise dosimeters: Accuracy and reliability in varied settings

    Directory of Open Access Journals (Sweden)

    Sheri Lynn Cook-Cunningham

    2014-01-01

    Full Text Available This study investigated the accuracy, reliability, and characteristics of three brands of personal noise dosimeters (N = 7 units in both pink noise (PN environments and natural environments (NEs through the acquisition of decibel readings, Leq readings and noise doses. Acquisition periods included repeated PN conditions, choir room rehearsals and participant (N = 3 Leq and noise dosages procured during a day in the life of a music student. Among primary results: (a All dosimeters exhibited very strong positive correlations for PN measurements across all instruments; (b all dosimeters were within the recommended American National Standard Institute (ANSI SI.25-1991 standard of ±2 dB (A of a reference measurement; and (c all dosimeters were within the recommended ANSI SI.25-1991 standard of ±2 dB (A when compared with each other. Results were discussed in terms of using personal noise dosimeters within hearing conservation and research contexts and recommendations for future research. Personal noise dosimeters were studied within the contexts of PN environments and NEs (choral classroom and the day in the life of collegiate music students. This quantitative study was a non-experimental correlation design. Three brands of personal noise dosimeters (Cirrus doseBadge, Quest Edge Eg5 and Etymotic ER200D were tested in two environments, a PN setting and a natural setting. There were two conditions within each environment. In the PN environment condition one, each dosimeter was tested individually in comparison with two reference measuring devices (Ivie and Easera while PN was generated by a Whites Instrument PN Tube. In condition two, the PN procedures were replicated for longer periods while all dosimeters measured the sound levels simultaneously. In the NE condition one, all dosimeters were placed side by side on a music stand and recorded sound levels of choir rehearsals over a 7-h rehearsal period. In NE, condition two noise levels were measured

  15. Personnel preferences in personnel planning and scheduling

    NARCIS (Netherlands)

    van der Veen, Egbert

    2013-01-01

    Summary The personnel of an organization often has two conflicting goals. Individual employees like to have a good work-life balance, by having personal preferences taken into account, whereas there is also the common goal to work efficiently. By applying techniques and methods from Operations

  16. Dosimetric properties of the pocket alarm dosimeter type Alnor RAD 21L, RAD 21H, RAD 22

    International Nuclear Information System (INIS)

    Hauser, M.; Burgkhardt, B.; Piesch, E.

    1981-02-01

    In personnel monitoring pocket dosimeters with build-in alarm devices are increasingly in use. The report presents results of a test performed at Karlsruhe for the pocket dose and alarm meter type Alnor RAD 21L, RAD 21H, RAD 22. The properties investigated are above all linearity and reproducibility of the dose reading as well as of the acoustic alarm indication, dependence of the dose reading on the photon energy, the direction of the radiation incidence, the dose rate, the temperature, operational characteristic of the batteries. (orig.) [de

  17. Sensitive silicon PIN-diode dosimeter for fast neutrons and method to control and increase its sensitivity

    International Nuclear Information System (INIS)

    Swinehart, P.R.; Swartz, J.M.

    1978-01-01

    With the personnel dosimeter, applicable e.g. in medicine, a dose of 0.1 rad for neutrons with an energy greater than 10 keV can be detected. In the range between 0.1 and 20 rad sensitivity is increased to 5 mV/rad. This sensitivity can be achieved by distributing the mass of the semiconductor material of the diode or equal to four times the reciprocal base width. Appropriate dimensions are 750 μm for the edge length of the end surface resp. diameter and 750 μm up to 5000 μm for the base width. (DG) [de

  18. Personnel Policy and Profit

    DEFF Research Database (Denmark)

    Bingley, Paul; Westergård-Nielsen, Niels Chr.

    2004-01-01

    personnel structure variation. It is found that personnel policy is strongly related to economic performance. At the margin, more hires are associated with lower profit, and more separations with higher profit. For the average firm, one new job, all else equal, is associated with ?2680 (2000 prices) lower...

  19. Facilities and procedures used for the performance testing of DOE personnel dosimetry systems

    Energy Technology Data Exchange (ETDEWEB)

    Roberson, P.L.; Fox, R.A.; Hogan, R.T.; Holbrook, K.L.; Hooker, C.D.; Yoder, R.C.

    1983-04-01

    Radiological calibration facilities for personnel dosimeter testing were developed at the Pacific Northwest Laboratory (PNL) for the Department of Energy (DOE) to provide a capability for evaluating the performance of DOE personnel dosimetry systems. This report includes the testing methodology used. The informational presented here meets requirements specified in draft ANSI N13.11 for the testing laboratory. The capabilities of these facilities include sealed source irradiations for /sup 137/Cs, several beta-particle emitters, /sup 252/Cf, and machine-generated x-ray beams. The x-ray beam capabilities include filtered techniques maintained by the National Bureau of Standards (NBS) and K-fluorescent techniques. The calibration techniques, dosimeter irradiation procedures, and dose-equivalent calculation methods follow techniques specified by draft ANSI N13.11 where appropriate.

  20. Facilities and procedures used for the performance testing of DOE personnel-dosimetry systems

    International Nuclear Information System (INIS)

    Roberson, P.L.; Fox, R.A.; Hogan, R.T.; Holbrook, K.L.; Hooker, C.D.; Yoder, R.C.

    1983-04-01

    Radiological calibration facilities for personnel dosimeter testing were developed at the Pacific Northwest Laboratory (PNL) for the Department of Energy (DOE) to provide a capability for evaluating the performance of DOE personnel dosimetry systems. This report includes the testing methodology used. The informational presented here meets requirements specified in draft ANSI N13.11 for the testing laboratory. The capabilities of these facilities include sealed source irradiations for 137 Cs, several beta-particle emitters, 252 Cf, and machine-generated x-ray beams. The x-ray beam capabilities include filtered techniques maintained by the National Bureau of Standards (NBS) and K-fluorescent techniques. The calibration techniques, dosimeter irradiation procedures, and dose-equivalent calculation methods follow techniques specified by draft ANSI N13.11 where appropriate

  1. A pocket warning γ-dosimeter with numerical display

    International Nuclear Information System (INIS)

    Jones, A.R.

    1980-09-01

    A pocket warning dosimeter is described. It provides alarms (continuous tone and a flashing red light) when a presettable dose has been accumulated in the range .064 - 16.4 rads (0.64 - 164 μGy). This warning level can be selected in nine steps of 2 with a switch inside the dosimeter. The dose rate is indicated by a series of sound pulses whose repetition rate is proportional to the dose rate. At 1 rad/h (10 mGy/h) about 17 pluses/minute are emitted. The accumulated dose up to 20 rads (0.2 Gy) is displayed in steps of 1 mrad (10 μGy) with a liquid crystal display. A red LED lights before battery failure occurs. The effects of changes in temperature, battery voltage, dose rate and photon energy upon dosimeter sensitivity are presented. Finally, the applications of the dosimeter are discussed. (auth)

  2. Investigating potential physicochemical errors in polymer gel dosimeters

    International Nuclear Information System (INIS)

    Sedaghat, Mahbod; Lepage, Martin; Bujold, Rachel

    2011-01-01

    Measurement errors in polymer gel dosimetry can originate either during irradiation or scanning. One concern related to the exothermic nature of polymerization reaction was that the heat released in polymer gel dosimeters during irradiation modifies their dose response. In this paper, the effect of heat released from the exothermal polymerization reaction on the dose response of a number of dosimeters was studied. In addition, we investigated whether heat-generated geometric distortion existed in newly proposed gel dosimeters that contain highly thermoresponsive polymers. Our results suggest that despite a significant internal temperature increase in some gel compositions, their dose responses are not affected when oxygen is well expelled mechanically from the gel mixture. We also report on significant pre-irradiation instability in some recently developed polymer gel dosimeters but that geometric distortions were not observed. Data obtained by a set of small calibration vials are compared to those obtained from larger phantoms, and potential physicochemical causes of deviations between them are identified.

  3. UVB DNA dosimeters analyzed by polymerase chain reactors

    International Nuclear Information System (INIS)

    Yoshida, Hiroko; Regan, J.D.; Florida Inst. of Tech., Melbourne, FL

    1997-01-01

    Purified bacteriophage λ DNA was dried on a UV-transparent polymer film and served as a UVB dosimeter for personal and ecological applications. Bacteriophage λ DNA was chosen because it is commercially available and inexpensive, and its entire sequence is known. Each dosimeter contained two sets of DNA sandwiched between UV-transparent polymer films, one exposed to solar radiation (experimental) and another protected from UV radiation by black paper (control). The DNA dosimeter was then analyzed by a polymerase chain reaction (PCR) that amplifies a 500 base pair specific region of λ DNA. Photoinduced damage in DNA blocks polymerase from synthesizing a new strand; therefore, the amount of amplified product in UV-exposed DNA was reduced from that found in control DNA. The dried λ DNA dosimeter is compact, robust, safe and transportable, stable over long storage times and provides the total UVB dose integrated over the exposure time. (author)

  4. Investigating potential physicochemical errors in polymer gel dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Sedaghat, Mahbod; Lepage, Martin [Centre d' imagerie moleculaire de Sherbrooke, Departement de medecine nucleaire et radiobiologie, Universite de Sherbrooke, Sherbrooke, QC (Canada); Bujold, Rachel, E-mail: martin.lepage@usherbrooke.ca [Service de radio-oncologie, Centre hospitalier universitaire de Sherbrooke, Sherbrooke, QC (Canada)

    2011-09-21

    Measurement errors in polymer gel dosimetry can originate either during irradiation or scanning. One concern related to the exothermic nature of polymerization reaction was that the heat released in polymer gel dosimeters during irradiation modifies their dose response. In this paper, the effect of heat released from the exothermal polymerization reaction on the dose response of a number of dosimeters was studied. In addition, we investigated whether heat-generated geometric distortion existed in newly proposed gel dosimeters that contain highly thermoresponsive polymers. Our results suggest that despite a significant internal temperature increase in some gel compositions, their dose responses are not affected when oxygen is well expelled mechanically from the gel mixture. We also report on significant pre-irradiation instability in some recently developed polymer gel dosimeters but that geometric distortions were not observed. Data obtained by a set of small calibration vials are compared to those obtained from larger phantoms, and potential physicochemical causes of deviations between them are identified.

  5. Temperature, humidity and time. Combined effects on radiochromic film dosimeters

    DEFF Research Database (Denmark)

    Abdel-Fattah, A.A.; Miller, A.

    1996-01-01

    The effects of both relative humidity and temperature during irradiation on the dose response of FWT-60-00 and Riso B3 radiochromic film dosimeters have been investigated in the relative humidity (RH) range 11-94% and temperature range 20-60 degrees C for irradiation by Co-60 photons and 10-Me......V electrons. The results show that humidity and temperature cannot be treated as independent variables, rather there appears to be interdependence between absorbed dose, temperature, and humidity. Dose rate does not seem to play a significant role. The dependence of temperature during irradiation is +0.......25 +/- 0.1% per degrees C for the FWT-60-00 dosimeters and +0.5 +/- 0.1% per degrees C For Riso B3 dosimeters at temperatures between 20 and 50 degrees C and at relative humidities between 20 and 53%. At extreme conditions both with respect to temperature and to humidity, the dosimeters show much stronger...

  6. Comparison of the effectiveness of polymer gel dosimeters (Magic ...

    African Journals Online (AJOL)

    demonstrate that the gel dosimeters are best suited for nuclear medicine. Keywords: Magic ... International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, EBSCO, African. Index Medicus .... Reaction rate. 2.15E-6.

  7. Antioxidant effect of green tea on polymer gel dosimeter

    International Nuclear Information System (INIS)

    Samuel, E J J; Sathiyaraj, P; Deena, T; Kumar, D S

    2015-01-01

    Extract from Green Tea (GTE) acts as an antioxidant in acrylamide based polymer gel dosimeter. In this work, PAGAT gel was used for investigation of antioxidant effect of GTE.PAGAT was called PAGTEG (Polyacrylamide green tea extract gel dosimeter) after adding GTE. Free radicals in water cause pre polymerization of polymer gel before irradiation. Polyphenols from GTE are highly effective to absorb the free radicals in water. THPC is used as an antioxidant in polymer gel dosimeter but here we were replaced it by GTE and investigated its effect by spectrophotometer. GTE added PAGAT samples response was lower compared to THPC added sample. To increase the sensitivity of the PAGTEG, sugar was added. This study confirmed that THPC was a good antioxidant for polymer gel dosimeter. However, GTE also can be used as an antioxidant in polymer gel if use less quantity (GTE) and add sugar as sensitivity enhancer

  8. Storage Telemetry of Radionuclide Tracers by Implantable Thermoluminescent Dosimeters

    DEFF Research Database (Denmark)

    Bojsen, J.; Møller, U.; Christensen, Poul

    1977-01-01

    A storage telemetrical method using thermoluminescent (TL) dosimeters for long-term measurements of incorporated radioactive substances in unrestrained rats has been developed. The system has been used in combination with radiotelemetrical registration of the circadian temperature rhythm. By sequ...

  9. Triton and alpha-particle contribution from LiF converter for neutron dosimeter

    CERN Document Server

    Camacho, M E; Balcazar, M

    1999-01-01

    A personnel neutron dosimeter prototype based on chemical and electrochemical etched CR-39 detector, combined with LiF converter, has been calibrated using an ICRP-like phantom, under a heavy-water moderated Californium source neutron spectra; A conversion factor of 1.052+-126 spots cm sup - sup 2 mSv sup - sup 1 was obtained. The sealing properties of the detector holder showed a ten-fold reduction in radon background when it was tested in a high radon atmosphere. A convenient mechanical shock resistance was achieved in LiF converters by sintering to 11 tons pressure LiF powder at 650 deg. C, during one hour.

  10. Establishing personal dosimetry procedure using optically stimulated luminescence dosimeters in photon and mixed photon-neutron radiation fields

    International Nuclear Information System (INIS)

    Le Ngoc Thiem; Bui Duc Ky; Trinh Van Giap; Nguyen Huu Quyet; Ho Quang Tuan; Vu Manh Khoi; Chu Vu Long

    2017-01-01

    According to Vietnamese Law on Atomic Energy, personal dosimetry (PD) for radiation workers is required periodically in order to fulfil the national legal requirements on occupational radiation dose management. Since the radiation applications have become popular in Vietnamese society, the thermal luminescence dosimeters (TLDs) have been used as passive dosimeters for occupational monitoring in the nation. Together with the quick increase in radiation applications and the number of personnel working in radiation fields, the Optically Stimulated Luminescence Dosimeters (OSLDs) have been first introduced since 2015. This work presents the establishment of PD measuring procedure using OSLDs which are used for measuring photons and betas known as Inlight model 2 OSL (OSLDs-p,e) and for measuring mixed radiations of neutrons, photons and betas known as Inlight LDR model 2 (OSLDs-n,p,e). Such following features of OSLDs are investigated: detection limit, energy response, linearity, reproducibility, angular dependency and fading with both types of OSLDs-p,e and OSLDs-n,p,e. The result of an intercomparison in PD using OSLDs is also presented in the work. The research work also indicates that OSL dosimetry can be an alternative method applied in PD and possibly become one of the most popular personal dosimetry method in the future. (author)

  11. A new electret dosimeter for fast neutrons

    International Nuclear Information System (INIS)

    Campos, L.L.; Suarez, A.A.; Mascarenhas, S.

    1982-01-01

    A new electret for fast-neutron personnel dosimetry is described and calibration curves obtained. Its performance may be improved by changes in the wall composition and geometric parameters. The advantages of electrets over TL and film are the non-erasure of information, low cost, fast reading and portability. (U.K.)

  12. Angular dependence of the nanoDot OSL dosimeter

    OpenAIRE

    Kerns, James R.; Kry, Stephen F.; Sahoo, Narayan; Followill, David S.; Ibbott, Geoffrey S.

    2011-01-01

    Purpose: Optically stimulated luminescent detectors (OSLDs) are quickly gaining popularity as passive dosimeters, with applications in medicine for linac output calibration verification, brachytherapy source verification, treatment plan quality assurance, and clinical dose measurements. With such wide applications, these dosimeters must be characterized for numerous factors affecting their response. The most abundant commercial OSLD is the InLight∕OSL system from Landauer, Inc. The purpose of...

  13. The NRPB's new dosimeter and dose record keeping services

    International Nuclear Information System (INIS)

    Dennis, J.A.; Marshall, T.O.; Shaw, K.B.

    1976-01-01

    A new automated dosimeter and record keeping service which the National Radiological Protection Board (UK) intends to introduce in 1977 is described. The automated system, based on a thermoluminescent dosimeter, will be linked to a fully computerised record keeping system with automatic printing of dose records and Transfer Records operated at its Headquarters at Harwell. The new system will dispense with much manual labour which in the past has introduced inevitable errors and incurred increasing costs. (U.K.)

  14. Electrochemical development of particle tracks in CR-39 polymer dosimeter

    International Nuclear Information System (INIS)

    Hadlock, D.E.; Parkhurst, M.A.; Yang, C.S.; Groeger, J.; Johnson, J.R.; Huang, S.J.

    1985-09-01

    Electrochemical etching of CR-39 polymeric track etch neutron detectors results in proton-recoil tracks can be distinguished from background tracks much better than tracks developed solely by chemical etching. A newly designed and constructed electrochemical etching apparatus allows large numbers of dosimeters to be processed simultaneously with consistent results. Many processing systems have been developed for chemical and electrochemical etching of the track etch dosimeters. Three systems specifically show great promise and are being studied extensively

  15. Pixel readout ASIC for an APD based 2D X-ray hybrid pixel detector with sub-nanosecond resolution

    Energy Technology Data Exchange (ETDEWEB)

    Thil, Ch., E-mail: christophe.thil@ziti.uni-heidelberg.d [Heidelberg University, Institute of Computer Engineering, B6, 26, 68161 Mannheim (Germany); Baron, A.Q.R. [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Fajardo, P. [ESRF, Polygone Scientifique Louis Neel, 6, rue Jules Horowitz, 38000 Grenoble (France); Fischer, P. [Heidelberg University, Institute of Computer Engineering, B6, 26, 68161 Mannheim (Germany); Graafsma, H. [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Rueffer, R. [ESRF, Polygone Scientifique Louis Neel, 6, rue Jules Horowitz, 38000 Grenoble (France)

    2011-02-01

    The fast response and the short recovery time of avalanche photodiodes (APDs) in linear mode make those devices ideal for direct X-ray detection in applications requiring high time resolution or counting rate. In order to provide position sensitivity, the XNAP project aims at creating a hybrid pixel detector with nanosecond time resolution based on a monolithic APD sensor array with 32 x32 pixels covering about 1 cm{sup 2} active area. The readout is implemented in a pixelated front-end ASIC suited for the readout of such arrays, matched to pixels of 280{mu}mx280{mu}m size. Every single channel features a fast transimpedance amplifier, a discriminator with locally adjustable threshold and two counters with high dynamic range and counting speed able to accumulate X-ray hits with no readout dead time. Additionally, the detector can be operated in list mode by time-stamping every single event with sub-nanosecond resolution. In a first phase of the project, a 4x4 pixel test module is built to validate the conceptual design of the detector. The XNAP project is briefly presented and the performance of the readout ASIC is discussed.

  16. Pixel readout ASIC for an APD based 2D X-ray hybrid pixel detector with sub-nanosecond resolution

    International Nuclear Information System (INIS)

    Thil, Ch.; Baron, A.Q.R.; Fajardo, P.; Fischer, P.; Graafsma, H.; Rueffer, R.

    2011-01-01

    The fast response and the short recovery time of avalanche photodiodes (APDs) in linear mode make those devices ideal for direct X-ray detection in applications requiring high time resolution or counting rate. In order to provide position sensitivity, the XNAP project aims at creating a hybrid pixel detector with nanosecond time resolution based on a monolithic APD sensor array with 32 x32 pixels covering about 1 cm 2 active area. The readout is implemented in a pixelated front-end ASIC suited for the readout of such arrays, matched to pixels of 280μmx280μm size. Every single channel features a fast transimpedance amplifier, a discriminator with locally adjustable threshold and two counters with high dynamic range and counting speed able to accumulate X-ray hits with no readout dead time. Additionally, the detector can be operated in list mode by time-stamping every single event with sub-nanosecond resolution. In a first phase of the project, a 4x4 pixel test module is built to validate the conceptual design of the detector. The XNAP project is briefly presented and the performance of the readout ASIC is discussed.

  17. Evaluation of optical fibres as gamma radiation dosimeter

    International Nuclear Information System (INIS)

    Bohra, Dinesh; Chaudhary, H.S.; Panwar, Lalit; Vaijapurkar, S.G.; Bhatnagar, P.K.; Dasgupta, K.

    2005-01-01

    Semiconductor base gamma and neutron sensors are the fastest and popular dosimeters and are in competition with Thermoluminescence (TL) and Radio photoluminescence (RPL) dosimeters. All over the world armed forces require a dosimeter which records cumulative doses of ionizing radiations from mcGy to 10 Gy and is readable repeatedly without loss of dose information. TL dosimeters do not meet the criteria and RPL dosimeter meet the expectations and are in use by armed forces. Technologists have used laser as an excitation source to stimulate the glass and have achieved success in recording gamma doses of occupational/accidental span (mcGy to 10 Gy). However synthesizing RPL glass batches with exactly same characteristics predoses is a difficult task. Silicon base phosphorous doped step index multimode optical fibre can be made in a significant quantity and large number of dosimeters from it can be achieved with uniform predose. The radiation induced transmission loss gives a measure of gamma dose which is cumulative, readable repeatedly without loss of information. Assorted composition, core dia optical fibres have been synthesized and evaluated for dose linearity, dose rate independence, fading, length optimization. Here in is described some results of recent experiments and sensitivities achieved. (author)

  18. Calibration and performance testing of electronic personal dosimeters (EPD)

    International Nuclear Information System (INIS)

    Banaga, H.A.

    2008-04-01

    In modern radiation protection practices, active personal dosimeters are becoming absolutely necessary operational tools for satisfying the ALARA principle. The aim of this work was to carry out calibration and performance testing of ten electronic personal dosimeters (EPD) used for the individual monitoring. The EPDs were calibrated in terms of operation radiation protection quantity, personal dose equivalent, Hp (10). Calibrations were carried out at three of x-ray beam qualities described in ISO 4037 namely 60, 100 and 150 kV in addition to Cs-137 gamma ray quality. The calibrations were performed using polymethylmethacrylate (PMMA) phantom with dimensions 20*20*15 cm 3 . Conversion coefficient Hp (10)/K air for the phantom was also calculated. The response and linearity of the dosimeter at the specified energies were also tested. The EPDs tested showed that the calibration coefficient ranged from 0.60 to 1.31 and an equivalent response for the specified energies that ranged from 0.76 to 1.67. The study demonstrated the possibility of using non standard phantom for calibrating dosimeters used for individual monitoring. The dosimeters under study showed a good response in all energies except the response in quality 100 kV. The linearity of the dosimeters was within ±15%, with the exception of the quality 100 kV where this limit was exceeded.(Author)

  19. Characterization of Thymol blue Radiochromic dosimeters for high dose applications

    Directory of Open Access Journals (Sweden)

    Feras M. Aldweri

    2018-03-01

    Full Text Available Thymol blue (TB solutions and Thymol blue Polyvinyl Alcohol (TB-PVA films have been introduced as Radiochromic dosimeter for high dose applications. The dosimeters were irradiated with gamma ray (60Co source from 5 to 30 kGy for film, and from 0.150 kGy to 4 kGy for solution. The optical density of unirradiated and irradiated TB solution as well as TB-PVA film dosimeters were studied in terms of absorbance at 434 nm using UV/VIS spectrophotometer. The effects of scan temperature, light pre-gamma irradiation, dose rate, relative humidity and stability of the absorbance of solutions and films after irradiation were investigated. We found the dose sensitivity of TB solution and TB-PVA film dosimeters increases significantly with increases of the absorbed dose as well as with the increases of TB dye concentrations. The useful dose range of developed TB solutions and TB-PVA films dosimeters is in the range 0.125–1 kGy and of 5–20 kGy, respectively. Keywords: Dose sensitivity, Radio-chromic dosimeter, Thymol blue, Absorbance, Concentrations

  20. Experimental evaluation of a MOSFET dosimeter for proton dose measurements

    International Nuclear Information System (INIS)

    Kohno, Ryosuke; Nishio, Teiji; Miyagishi, Tomoko; Hirano, Eriko; Hotta, Kenji; Kawashima, Mitsuhiko; Ogino, Takashi

    2006-01-01

    The metal oxide semiconductor field-effect transistor (MOSFET) dosimeter has been widely studied for use as a dosimeter for patient dose verification. The major advantage of this detector is its size, which acts as a point dosimeter, and also its ease of use. The commercially available TN502RD MOSFET dosimeter manufactured by Thomson and Nielsen has never been used for proton dosimetry. Therefore we used the MOSFET dosimeter for the first time in proton dose measurements. In this study, the MOSFET dosimeter was irradiated with 190 MeV therapeutic proton beams. We experimentally evaluated dose reproducibility, linearity, fading effect, beam intensity dependence and angular dependence for the proton beam. Furthermore, the Bragg curve and spread-out Bragg peak were also measured and the linear-energy transfer (LET) dependence of the MOSFET response was investigated. Many characteristics of the MOSFET response for proton beams were the same as those for photon beams reported in previous papers. However, the angular MOSFET responses at 45, 90, 135, 225, 270 and 315 degrees for proton beams were over-responses of about 15%, and moreover the MOSFET response depended strongly on the LET of the proton beam. This study showed that the angular dependence and LET dependence of the MOSFET response must be considered very carefully for quantitative proton dose evaluations

  1. Radiation measured for ISS-Expedition 12 with different dosimeters

    International Nuclear Information System (INIS)

    Zhou, D.; Semones, E.; Gaza, R.; Johnson, S.; Zapp, N.; Weyland, M.

    2007-01-01

    Radiation in low Earth orbit (LEO) is mainly from Galactic Cosmic Rays (GCR), solar energetic particles and particles in South Atlantic Anomaly (SAA). These particles' radiation impact to astronauts depends strongly on the particles' linear energy transfer (LET) and is dominated by high LET radiation. It is important to investigate the LET spectrum for the radiation field and the influence of radiation on astronauts. At present, the best active dosimeters used for all LET are the tissue equivalent proportional counter (TEPC) and silicon detectors; the best passive dosimeters are thermoluminescence dosimeters (TLDs) or optically stimulated luminescence dosimeters (OSLDs) for low LET and CR-39 plastic nuclear track detectors (PNTDs) for high LET. TEPC, CR-39 PNTDs, TLDs and OSLDs were used to investigate the radiation for space mission Expedition 12 (ISS-11S) in LEO. LET spectra and radiation quantities (fluence, absorbed dose, dose equivalent and quality factor) were measured for the mission with these different dosimeters. This paper introduces the operation principles for these dosimeters, describes the method to combine the results measured by CR-39 PNTDs and TLDs/OSLDs, presents the experimental LET spectra and the radiation quantities

  2. Perofrmance testing of personnel dosimetry services. Final report of a two-year pilot study, October 1977-September 1979

    International Nuclear Information System (INIS)

    Plato, P.; Hudson, G.

    1980-01-01

    A two-year pilot study was conducted of the Health Physics Society Standards Committee (HPSSC) Standard titled, Criteria for Testing Personnel Dosimetry Performance. The objectives of the pilot study were: to give processors an opportunity to correct any problems that are uncovered; to develop operational and administrative prodedures to be used later by a permanent testing laboratory; and to determine whether the proposed HPSSC Standard provides an adequate and practical test of dosimetry performance. Fifty-nine dosimetry processors volunteered to submit dosimeters for test irradiations according to the requirements of the HPSSC Standard. The feasibility of using the HPSSC Standard for a future mandatory testing program for personnel dosimetry processors is discussed. This report shows the results of the pilot study and contains recommendations for revisions in the Standard that will make a mandatory testing program useful to regulatory agencies, dosimetry processors, and radiation workers that use personnel dosimeters

  3. The roles played by the Canadian General Electric Company's Atomic Power Department in Canada's nuclear power program: work, organization and success in APD, 1955-1995

    International Nuclear Information System (INIS)

    Cantello, G.W.

    2003-01-01

    This thesis explores the roles played by the Canadian General Electric Company's Atomic Power Department (APD) in Canada's distinctive nuclear power program. From the establishment of APD in 1955 until the completion of the KANUPP project in Pakistan in 1972, the company's strategy encompassed the design, manufacture, and commissioning of entire nuclear power projects in Canada and abroad. APD then developed a specialized role in the design and supply of complete nuclear fuel handling systems, nuclear fuel bundles, and service work, that sustained a thriving workplace. Five key factors are identified as the reasons behind the long and successful history of the department: (1) Strong, capable and efficient management from the start, (2) Flexible organizational structure, (3) Extremely competent design group, (4) Excellent manufacturing, test, commissioning and service capabilities, (5) Correctly identifying, at the right time, the best fields in which to specialize. (author)

  4. Automation of dosimeters calibration for radiotherapy in secondary dosimetric calibration laboratory of the CPHR; Automatizacion de la calibracion de dosimetros de radioterapia en el laboratorio secundario de calibracion dosimetrica del CPHR

    Energy Technology Data Exchange (ETDEWEB)

    Acosta, Andy L. Romero; Lores, Stefan Gutierrez, E-mail: c19btm@frcuba.co.cu [Centro de Proteccion e Higiene de las Radiaciones (CPHR), La Habana (Cuba)

    2013-11-01

    This paper presents the design and implementation of an automated system for measurements in the calibration of reference radiation dosimeters. It was made a software application that performs the acquisition of the measured values of electric charge, calculated calibration coefficient and automates the calibration certificate issuance. These values are stored in a log file on a PC. The use of the application improves control over the calibration process, helps to humanize the work and reduces personnel exposure. The tool developed has been applied to the calibration of dosimeters radiation patterns in the LSCD of the Centro de Proteccion e Higiene de las Radiaciones, Cuba.

  5. Training of nonlicensed personnel

    International Nuclear Information System (INIS)

    Hetrick, D.E.

    1975-01-01

    The safety and efficiency with which a station operates is a function of the competence and proficiency of all personnel. This includes the nonlicensed personnel who make up the bulk of the station staff. Thus the training of these members of the station complement is an important function in overall station performance. Standards, regulations, regulatory guides, and codes provide guidance to the training requirements for such personnel. Training needs and objectives must be established, a plan prepared and then all incorporated into a training program. A well planned and operated training program will stimulate effective communications between the different groups within the station and between the station and off site support groups

  6. Kepatuhan Menggunakan Alat Pelindung Diri (APD Ditinjau dari Pengetahuan dan Perilaku pada Petugas Instalasi Pemeliharaan Sarana Dan Prasarana Rumah Sakit (IPSRS.

    Directory of Open Access Journals (Sweden)

    Rizka Ayu Zahara

    2017-12-01

    Full Text Available Abstrak: Alat Pelindung Diri (APD berfungsi untuk melindungi tubuh terhadap bahaya-bahaya kecelakaan kerja dan mengurangi tingkat keparahan dari kecelakaan kerja yang terjadi. Penelitian ini bertujuan untuk mengetahui korelasi antara pengetahuan dan perilaku petugas Instalasi Pemeliharaan Sarana dan Prasarana Rumah Sakit (IPSRS dengan kepatuhan terhadap penggunaan Alat Pelindung Diri (APD. Desain penelitian ini adalah Cross Sectional. Populasi adalah seluruh petugas IPSRS di RSUD Siti Aisyah Kota Lubuklinggau sebanyak 64 orang. Penelitian dilaksanakan pada bulan Agustus 2017. Analisis data menggunakan uji statistik chi-Square. Hasil penelitian menunjukkan adanya korelasi antara kepatuhan menggunakan Alat Pelindung Diri APD pengetahuan (p value = 0, 001, dan perilaku (p value = 0, 006. Pihak RSUD diharapkan dapat menerapkan Standar Prosedur Operasional (SPO yang lebih tegas, melakukan pelatihan tentang penggunaan APD, dan meningkatkan pengawasan terhadap kepatuhan petugas dalam menggunakan APD. Kata Kunci : Pengetahuan, Perilaku, Kepatuhan Alat Pelindung Diri (APD. ADHERENCE USING PERSONAL PROTECTIVE EQUIPMENT (PPE IN TERMS OF THE KNOWLEDGE AND BEHAVIOR OF OFFICER INSTALLATION MAINTENANCE FACILITIES AND INFRASTRUCTURE HOSPITAL (IPSRS Abstract: Personal Protective Equipment (PPE serves to protect the body against occupational injuries and reduce the severity of work accidents that occur. This study aims to determine the correlation between the knowledge and behavior of the officer of the Installation of Hospital Facilities and Infrastructure Maintenance (IPSRS with the adherence to the use of Personal Protective Equipment (PPE. The design of this study was Cross Sectional. The population is all IPSRS officers in RSUD Siti Aisyah Lubuklinggau City as many as 64 people. The study was conducted in August 2017. The data analysis used chi-square statistical test. The results showed that there was a correlation between adherence using Personal

  7. Development of a multichannel dosimeter for radiotherapy

    International Nuclear Information System (INIS)

    Menezes, Claudio Jose Mesquita

    2000-06-01

    In radiotherapy, verification of the patient dose is of great important for the success of the treatment. Uncertainties in the evaluation of this dose can produce serious complications such as the loss of the control of the disease and damage to normal tissue. Semiconductor detectors present advantages over other types of radiation detectors such as ionization chambers and thermoluminescent dosimeters including small dimensions, high sensitivity and fast response. In this work, a multichannel dosimetric system is linear with dose, for a 6 MV x-ray beam and also with a beam of cobalt-60 gamma rays. The coefficients of determination of the calibration curves were better then 0,9998 in all cases. The four sensors presented similar response with the dose for different field sizes. The variation of the response was smaller than 1%. In a related study, depth dose was measured, and the results showed a good agreement compared to theoretical values. The angular response of the detectors showed a variation of 7% for angles of 45 deg C. Using the Anderson Random phantom, dose at the isocenter was determined from measurements of the surface dose. From the results obtained it can be concluded that the dosimetric system developed is adequate for the evaluation of many parameters in radiation fields used in radiotherapy. This system can be used to measure the patient entrance dose under treatment conditions, and the equipment can be used in the radiotherapy quality assurance program. (author)

  8. Commissioning and characteristics of MOSFET dosimeter

    International Nuclear Information System (INIS)

    Gopiraj, A.; Billimagga, Ramesh S.; Rekha, M.; Ramasubramaniam, V.

    2007-01-01

    The verification of the dose delivered to a patient is an important part of the quality assurance in radiotherapy. Thermoluminescent dosimeters (TLDs) and semiconductor diodes were mostly used for this purpose. Recently Metal Oxide Semiconductor field effect transistors (MOSFET) have been proposed for the application in radiotherapy. Each type of detector has its own advantages and disadvantages. The TLD size is very small and therefore can be used both for measurement and dose delivered to a patient and for measurements of dose distribution in a humanoid phantom. The main disadvantages of the TLDs are the time required by the preparation procedure and the limited accuracy which depends on the experience of the user. Additionally, TLDs do not allow an immediate readout. The main disadvantages of semiconductor diodes are the necessity of using a cable which can disturb normal clinical work especially when in vivo measurements are carried out, and the necessity of applying of many correction factors to achieve high accuracy. We procured MOSFET system from Thomson and Nielsen Electronic Ltd. The reproducibility as a function of dose and linearity and calibration factor of the MOSFET detectors were measured. The effects of energy, field size and accumulated dose on the response of the detectors were investigated

  9. Excited species in the FBX dosimeter system

    International Nuclear Information System (INIS)

    Gupta, B.L.

    2003-01-01

    In the FBX dosimeter solution, the excitation of xylenol orange (XO) produces maximum emission at 550-575 nm both at room and liquid nitrogen temperatures (about 85%) having a lifetime of 0.20-0.36 ns. In addition, at room temperature there is an emission at 350 nm for the excitation at 260 nm (about 15%) having a longer lifetime of 3.71-4.01 ns. Benzoic acid (BA) has excitation at 284-295 nm and emission at 320-365 nm having a lifetime of 1.38 ns. In an aqueous solution containing 5x10 -3 mol dm -3 BA, 2x10 -4 mol dm -3 XO and 0.04 mol dm -3 H 2 SO 4 there is no XO emission at 550 nm due to UV absorption at 260 nm by BA. In this solution, 2 emissions are observed near 350-360 nm, having lifetimes of 1.25 ns (89%) and 2.86 ns (11%). The wavelengths for the emission of XO and absorption of ferric-XO complex are nearly the same. Excited XO produces oxidation of ferrous ions and BA increases the chain length

  10. Evaluation of environmental monitoring thermoluminescent dosimeter locations

    International Nuclear Information System (INIS)

    Kinnison, R.

    1992-12-01

    Geostatistics, particularly kriging, has been used to assess the adequacy of the existing NTS thermoluminescent dosimeter network for determination of environmental exposure levels. (Kriging is a linear estimation method that results in contour plots of both the pattern of the estimated gamma radiation over the area of measurements and also of the standard deviations of the estimated exposure levels.) Even though the network was not designed as an environmental monitoring network, ft adequately serves this function in the region of Pahute and Rainier Mesas.. The Yucca Flat network is adequate only if a reasonable definition of environmental exposure levels is required; R is not adequate for environmental monitoring in Yucca Flat if a coefficient of variation of 10 percent or less is chosen as the criterion for network design. A revision of the Yucca Flat network design should be based on a square grid pattern with nodes 5000 feet (about one mile) apart, if a 10 percent coefficient of variation criterion is adopted. There were insufficient data for southern and western sections of the NTS to perform the geostatistical analysis. A very significant finding was that a single network design cannot be used for the entire NTS, because different areas have different variograms. Before any design can be finalized, the NTS management must specify the exposure unit area and coefficient of variation that are to be used as design criteria

  11. Characteristics and application of alanine dosimeter 'Aminogray'

    International Nuclear Information System (INIS)

    Kashiwazaki, Shigeru; Matsuyama, Shigeki; Hatta, Toshimasa; Yagyu, Hideki; Kojima, Takuji; Tanaka, Ryuichi; Morita, Yohsuke.

    1988-01-01

    Recently, accompanying the progress of nuclear power generation and space development, the evaluation of reliability for the materials and parts used under irradiation has become important. For the evaluation of reliability, the accurate grasp of radiation dose is the prerequisite. In some case, the measurement of cumulative dose in a long period in an actual environment becomes necessary. In this paper, the characteristics and application of a new dosimeter element 'Aminogray' which is suitable to the above requirement are reported. Aminogray is rodshape element made by forming alanine, a kind of amino acid, using a binder polymer, and the alanine content is 70 wt.%, and the polymer is polystyrene. An element of 3 mm diameter and 30 mm length is enclosed in a polystyrene cylinder of 4 mm thickness. This thickness was determined by considering the electronic equilibrium condition in Co-60 gamma-ray irradiation. The principle of the measurement is to determine a dose by measuring the amount of free radicals produced in alanine by radiation using ESR method. The free radicals are extremely stable, and exist for a long period, and the amount of radical production is proportional to absorbed dose. The development, characteristics and application of Aminogray are reported. (K.I.)

  12. Civilian Personnel: Career Management

    National Research Council Canada - National Science Library

    2001-01-01

    This revision; (1) Contains changes required by the establishment of a consolidated and realigned management structure for civilian personnel, manpower, and related functions in the Office of the Assistant Secretary of the Army...

  13. Personnel neutron dosimetry

    International Nuclear Information System (INIS)

    Hankins, D.

    1982-04-01

    This edited transcript of a presentation on personnel neutron discusses the accuracy of present dosimetry practices, requirements, calibration, dosemeter types, quality factors, operational problems, and dosimetry for a criticality accident. 32 figs

  14. Monte Carlo simulation experiments on box-type radon dosimeter

    International Nuclear Information System (INIS)

    Jamil, Khalid; Kamran, Muhammad; Illahi, Ahsan; Manzoor, Shahid

    2014-01-01

    Epidemiological studies show that inhalation of radon gas ( 222 Rn) may be carcinogenic especially to mine workers, people living in closed indoor energy conserved environments and underground dwellers. It is, therefore, of paramount importance to measure the 222 Rn concentrations (Bq/m 3 ) in indoors environments. For this purpose, box-type passive radon dosimeters employing ion track detector like CR-39 are widely used. Fraction of the number of radon alphas emitted in the volume of the box type dosimeter resulting in latent track formation on CR-39 is the latent track registration efficiency. Latent track registration efficiency is ultimately required to evaluate the radon concentration which consequently determines the effective dose and the radiological hazards. In this research, Monte Carlo simulation experiments were carried out to study the alpha latent track registration efficiency for box type radon dosimeter as a function of dosimeter’s dimensions and range of alpha particles in air. Two different self developed Monte Carlo simulation techniques were employed namely: (a) Surface ratio (SURA) method and (b) Ray hitting (RAHI) method. Monte Carlo simulation experiments revealed that there are two types of efficiencies i.e. intrinsic efficiency (η int ) and alpha hit efficiency (η hit ). The η int depends upon only on the dimensions of the dosimeter and η hit depends both upon dimensions of the dosimeter and range of the alpha particles. The total latent track registration efficiency is the product of both intrinsic and hit efficiencies. It has been concluded that if diagonal length of box type dosimeter is kept smaller than the range of alpha particle then hit efficiency is achieved as 100%. Nevertheless the intrinsic efficiency keeps playing its role. The Monte Carlo simulation experimental results have been found helpful to understand the intricate track registration mechanisms in the box type dosimeter. This paper explains that how radon

  15. Development of a novel depth of interaction PET detector using highly multiplexed G-APD cross-strip encoding

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, A., E-mail: armin.kolb@med.uni-tuebingen.de; Parl, C.; Liu, C. C.; Pichler, B. J. [Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tübingen (Germany); Mantlik, F. [Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tübingen, Germany and Department of Empirical Inference, Max Planck Institute for Intelligent Systems, 72076 Tübingen (Germany); Lorenz, E. [Max Planck Institute for Physics, Föhringer Ring 6, 80805 München (Germany); Renker, D. [Department of Physics, Technische Universität München, 85748 Garching (Germany)

    2014-08-15

    Purpose: The aim of this study was to develop a prototype PET detector module for a combined small animal positron emission tomography and magnetic resonance imaging (PET/MRI) system. The most important factor for small animal imaging applications is the detection sensitivity of the PET camera, which can be optimized by utilizing longer scintillation crystals. At the same time, small animal PET systems must yield a high spatial resolution. The measured object is very close to the PET detector because the bore diameter of a high field animal MR scanner is limited. When used in combination with long scintillation crystals, these small-bore PET systems generate parallax errors that ultimately lead to a decreased spatial resolution. Thus, we developed a depth of interaction (DoI) encoding PET detector module that has a uniform spatial resolution across the whole field of view (FOV), high detection sensitivity, compactness, and insensitivity to magnetic fields. Methods: The approach was based on Geiger mode avalanche photodiode (G-APD) detectors with cross-strip encoding. The number of readout channels was reduced by a factor of 36 for the chosen block elements. Two 12 × 2 G-APD strip arrays (25μm cells) were placed perpendicular on each face of a 12 × 12 lutetium oxyorthosilicate crystal block with a crystal size of 1.55 × 1.55 × 20 mm. The strip arrays were multiplexed into two channels and used to calculate the x, y coordinates for each array and the deposited energy. The DoI was measured in step sizes of 1.8 mm by a collimated {sup 18}F source. The coincident resolved time (CRT) was analyzed at all DoI positions by acquiring the waveform for each event and applying a digital leading edge discriminator. Results: All 144 crystals were well resolved in the crystal flood map. The average full width half maximum (FWHM) energy resolution of the detector was 12.8% ± 1.5% with a FWHM CRT of 1.14 ± 0.02 ns. The average FWHM DoI resolution over 12 crystals was 2.90

  16. Implementation of a dosimetry service for the occupationally exposed personnel of the ESFM-IPN

    International Nuclear Information System (INIS)

    Hernandez A, Y.; Sanchez R, A. A.; Ceron R, P. V.; Rivera M, T.; Vega C, H. R.

    2014-10-01

    Because the ionizing radiations handling implies a risk for the health, is necessary to take a control of the radiation quantity that the occupationally exposed personnel receives during their daily work with ionizing radiations. For this purpose there are several types of dosimetry and companies that provide the service, but taking advantage that the Escuela Superior de Fisica y Matematicas del Instituto Politecnico Nacional (ESFM-IPN) possesses a thermoluminescence equipment (Tl) was decided to develop a personnel dosimetry service for gammas, with thermoluminescent glasses of type TLD-100. First one carries out a glasses characterization, for which the glasses were washed with a methyl alcohol solution, without rubbing them for not damaging them; after the drying, they were subjected to a temperature of 400 C during one hour and later on 100 grades C for two hours in order to erasing them the bottom information that they could have. 200 glasses were exposed to gamma radiation coming from a Cobalt 60 source property of ESFM-IPN in order to selecting the glasses that had a response whose precision was inside a standard deviation. Of this characterization 80 dosimeters were selected that had better response according to the obtained readings as well as of their shine curves. These selected TLD-100 glasses were irradiated to different dose of gamma radiation and with those readings it was built a dose response curve in m R against readings of electric load in pick Coulombs (pCou). The response curve was a direct line or calibration curve. As final exercise some glasses of this selected lot were subjected to irradiation dose not known by the person that carried out the readings and this way was proven that the results were appropriate with the calibration curve. Finally these dosimeters were placed in port-dosimeters and erased guides of dosimeters, of equipment use and dosimeters lecture were also elaborated. (Author)

  17. Application of Glycine-TTC dosimeter in gamma radiation processing facility

    International Nuclear Information System (INIS)

    Shinde, S.H.; Mondal, S.; Kulkarni, M.S.

    2018-01-01

    Glycine-TTC dosimeter was found to have a useful dose range of 5 to 30 kGy using spectro-photometric read-out method. Potential use of this dosimeter was demonstrated by measuring dose-rate in gamma chamber GC 900. The aim of the present study was to verify the performance of this dosimeter in actual industrial processing conditions encountered in radiation processing facility such as Gamma Radiation Processing Plant for Spices (GRPPS), BRIT, Vashi. Accordingly, glycine-TTC dosimeters were irradiated along with routine dosimeter viz. ceric-cerous of GRPPS and reference standard dosimeter viz. alanine EPR

  18. Imaging performance of LabPET APD-based digital PET scanners for pre-clinical research

    International Nuclear Information System (INIS)

    Bergeron, Mélanie; Cadorette, Jules; Beaudoin, Jean-François; Lecomte, Roger; Tétrault, Marc-André; Leroux, Jean-Daniel; Fontaine, Réjean

    2014-01-01

    The LabPET is an avalanche photodiode (APD) based digital PET scanner with quasi-individual detector read-out and highly parallel electronic architecture for high-performance in vivo molecular imaging of small animals. The scanner is based on LYSO and LGSO scintillation crystals (2×2×12/14 mm 3 ), assembled side-by-side in phoswich pairs read out by an APD. High spatial resolution is achieved through the individual and independent read-out of an individual APD detector for recording impinging annihilation photons. The LabPET exists in three versions, LabPET4 (3.75 cm axial length), LabPET8 (7.5 cm axial length) and LabPET12 (11.4 cm axial length). This paper focuses on the systematic characterization of the three LabPET versions using two different energy window settings to implement a high-efficiency mode (250–650 keV) and a high-resolution mode (350–650 keV) in the most suitable operating conditions. Prior to measurements, a global timing alignment of the scanners and optimization of the APD operating bias have been carried out. Characteristics such as spatial resolution, absolute sensitivity, count rate performance and image quality have been thoroughly investigated following the NEMA NU 4-2008 protocol. Phantom and small animal images were acquired to assess the scanners' suitability for the most demanding imaging tasks in preclinical biomedical research. The three systems achieve the same radial FBP spatial resolution at 5 mm from the field-of-view center: 1.65/3.40 mm (FWHM/FWTM) for an energy threshold of 250 keV and 1.51/2.97 mm for an energy threshold of 350 keV. The absolute sensitivity for an energy window of 250–650 keV is 1.4%/2.6%/4.3% for LabPET4/8/12, respectively. The best count rate performance peaking at 362 kcps is achieved by the LabPET12 with an energy window of 250–650 keV and a mouse phantom (2.5 cm diameter) at an activity of 2.4 MBq ml −1 . With the same phantom, the scatter fraction for all scanners is about

  19. Using Deep Learning for Gamma Ray Source Detection at the First G-APD Cherenkov Telescope (FACT)

    Science.gov (United States)

    Bieker, Jacob

    2018-06-01

    Finding gamma-ray sources is of paramount importance for Imaging Air Cherenkov Telescopes (IACT). This study looks at using deep neural networks on data from the First G-APD Cherenkov Telescope (FACT) as a proof-of-concept of finding gamma-ray sources with deep learning for the upcoming Cherenkov Telescope Array (CTA). In this study, FACT’s individual photon level observation data from the last 5 years was used with convolutional neural networks to determine if one or more sources were present. The neural networks used various architectures to determine which architectures were most successful in finding sources. Neural networks offer a promising method for finding faint and extended gamma-ray sources for IACTs. With further improvement and modifications, they offer a compelling method for source detection for the next generation of IACTs.

  20. Solid-state personal dosimeter using dose conversion algorithm

    International Nuclear Information System (INIS)

    Lee, B.J.; Lee, Wanno; Cho, Gyuseong; Chang, S.Y.; Rho, S.R.

    2003-01-01

    Solid-state personal dosimeters using semiconductor detectors have been widely used because of their simplicity and real time operation. In this paper, a personal dosimeter based on a silicon PIN photodiode has been optimally designed by the Monte Carlo method and also developed. For performance test, the developed dosimeter was irradiated within the energy range between 50 keV and 1.25 MeV, the exposure dose rate between 3 mR/h and 25 R/h. The thickness of 0.2 mm Cu and 1.0 mm Al was selected as an optimal filter by simulation results. For minimizing the non-linear sensitivity on energy, dose conversion algorithm was presented, which was able to consider pulse number as well as pulse amplitude related to absorbed energies. The sensitivities of dosimeters developed by the proposed algorithm and the conventional method were compared and analyzed in detail. When dose conversion algorithm was used, the linearity of sensitivity was better about 38%. This dosimeter will be used for above 65 keV within the relative response of ±10% to 137 Cs

  1. A critical assessment of two types of personal UV dosimeters.

    Science.gov (United States)

    Seckmeyer, Gunther; Klingebiel, Marcus; Riechelmann, Stefan; Lohse, Insa; McKenzie, Richard L; Liley, J Ben; Allen, Martin W; Siani, Anna-Maria; Casale, Giuseppe R

    2012-01-01

    Doses of erythemally weighted irradiances derived from polysulphone (PS) and electronic ultraviolet (EUV) dosimeters have been compared with measurements obtained using a reference spectroradiometer. PS dosimeters showed mean absolute deviations of 26% with a maximum deviation of 44%, the calibrated EUV dosimeters showed mean absolute deviations of 15% (maximum 33%) around noon during several test days in the northern hemisphere autumn. In the case of EUV dosimeters, measurements with various cut-off filters showed that part of the deviation from the CIE erythema action spectrum was due to a small, but significant sensitivity to visible radiation that varies between devices and which may be avoided by careful preselection. Usually the method of calibrating UV sensors by direct comparison to a reference instrument leads to reliable results. However, in some circumstances the quality of measurements made with simple sensors may be over-estimated. In the extreme case, a simple pyranometer can be used as a UV instrument, providing acceptable results for cloudless skies, but very poor results under cloudy conditions. It is concluded that while UV dosimeters are useful for their design purpose, namely to estimate personal UV exposures, they should not be regarded as an inexpensive replacement for meteorological grade instruments. © 2011 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2011 The American Society of Photobiology.

  2. Design, construction and characterization of a dosimeter for neutron radiation

    International Nuclear Information System (INIS)

    Souto, Eduardo de Brito

    2007-01-01

    An individual dosimeter for neutron-gamma mixed field dosimetry was design and developed aiming monitoring the increasing number of workers potentially exposed to neutrons. The proposed dosimeter was characterized to an Americium-Beryllium source spectrum and dose range of radiation protection interest (up to 20 mSv). Thermoluminescent albedo dosimetry and nuclear tracks dosimetry, traditional techniques found in the international literature, with materials of low cost and national production, were used. A commercial polycarbonate, named SS-1, was characterized for solid state tack detector application. The chemical etching parameters and the methodology of detectors evaluation were determined. The response of TLD-600, TLD-700 and SS-1 were studied and algorithms for dose calculation of neutron and gamma radiation of Americium- Beryllium sources were proposed. The ratio between thermal, albedo and fast neutrons responses, allows analyzing the spectrum to which the dosimeter was submitted and correcting the track detector response to variations in the radiation incidence angle. The new dosimeter is fully characterized, having sufficient performance to be applied as neutron dosimeter in Brazil. (author)

  3. Temperature, humidity and time., Combined effects on radiochromic film dosimeters

    International Nuclear Information System (INIS)

    Abdel-Fattah, A.A.; Miller, A.

    1996-01-01

    The effects of both relative humidity and temperature during irradiation on the dose response of FWT-60-00 and Riso B3 radiochromic film dosimeters have been investigated in the relative humidity (RH) range 11-94% and temperature range 20-60 o C for irradiation by 60 Co photons and 10-MeV electrons. The results show that humidity and temperature cannot be treated as independent variables, rather there appears to be interdependence between absorbed dose, temperature, and humidity. Dose rate does not seem to play a significant role. The dependence of temperature during irradiation is + 0.25 ± 0.1% per o C for the FWT-60-00 dosimeters and +0.5 ± 0.1% per o C for Riso B3 dosimeters at temperatures between 20 and 50 o C and at relative humidities between 20 and 53%. At extreme conditions both with respect to temperature and to humidity, the dosimeters show much stronger dependences. Whenever possible one should use dosimeters sealed in pouches under controlled intermediate humidity conditions (30-50%) or, if that is impractical, one should maintain conditions of calibration as close as possible to the conditions of use. Without that precaution, severe dosimetry errors may result. (author)

  4. An assessment of radiotherapy dosimeters based on CVD grown diamond

    International Nuclear Information System (INIS)

    Ramkumar, S.; Buttar, C.M.; Conway, J.; Whitehead, A.J.; Sussman, R.S.; Hill, G.; Walker, S.

    2001-01-01

    Diamond is potentially a very suitable material for use as a dosimeter for radiotherapy. Its radiation hardness, the near tissue equivalence and chemical inertness are some of the characteristics of diamond, which make it well suited for its application as a dosimeter. Recent advances in the synthesis of diamond by chemical vapour deposition (CVD) technology have resulted in the improvement in the quality of material and increased its suitability for radiotherapy applications. We report in this paper, the response of prototype dosimeters based on two different types (CVD1 and CVD2) of CVD diamond to X-rays. The diamond devices were assessed for sensitivity, dependence of response on dose and dose rate, and compared with a Scanditronix silicon photon diode and a PTW natural diamond dosimeter. The diamond devices of CVD1 type showed an initial increase in response with dose, which saturates after ∼6 Gy. The diamond devices of CVD2 type had a response at low fields ( 1162.8 V/cm), the CVD2-type devices showed polarisation and dose-rate dependence. The sensitivity of the CVD diamond devices varied between 82 and 1300 nC/Gy depending upon the sample type and the applied voltage. The sensitivity of CVD diamond devices was significantly higher than that of natural diamond and silicon dosimeters. The results suggest that CVD diamond devices can be fabricated for successful use in radiotherapy applications

  5. Calibration of film dosimeters by means of absorbed dose calorimeters

    International Nuclear Information System (INIS)

    Nikolaev, S.M.; Vanyushkin, B.M.; Kon'kov, N.G.

    1980-01-01

    Methods of graduating film dosimeters by means of calorimeters of absorbed doses, are considered. Graduating of film dosimeters at the energies of accelerated electrons from 4 to 10 MeV can be carried out by means of quasiadiabatic calorimeter of local absorption, the absorber thickness of which should not exceed 5-10% of Rsub(e) value, where Rsub(e) - free electron path of the given energy. In this case film is located inside the calorimeter. For graduating films with thickness not less than (0.1-0.2)Rsub(e) it is suggested to use calorimeter of full absorption; then the graduated dosimeters are located in front of the calorimeter. Graduation of films at small energies of electrons is exercised by means of a package of films, approximately Rsub(e) thick. A design of quasiadiabatic calorimeter, intended for graduating dosimeters within the energy range of electron beam from 4 to 10 MeV, is considered. The quasiadiabatic calorimeter is a thin graphite tablet with heater and thermocouple, surrounded by foam plastic thermostating case. Electricity quantity, accumulated during the radiation field pass, is measured in the case of using the quasiadiabatic calorimeter for film graduating. The results of graduating film dosimeters, obtained using film package with Rsub(e) thickness, are presented. The obtained results coincide within 5% limits with the data known beforehand [ru

  6. Poster - 01: LabPET II Pixelated APD-Based PET Scanner for High-Resolution Preclinical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lecomte, Roger; Arpin, Louis; Beaudoin, Jean-François; Bergeron, Mélanie; Bouchard, Jonathan; Bouziri, Haithem; Cadorette, Jules; Gaudin, Émilie; Jürgensen, Nadia; Koua, Konin Calliste; Trépanier, Pierre-Yves Lauzier; Leroux, Jean-Daniel; Loignon-Houle, Francis; Njejimana, Larissa; Paillé, Maxime; Paulin, Caroline; Pepin, Catherine; Pratte, Jean-François; Samson, Arnaud; Thibaudeau, Christian [Université de Sherbrooke, Université de Sherbrooke, CIMS/CRCHUS, Université de Sherbrooke, Université de Sherbrooke, Université de Sherbrooke, CIMS/CRCHUS, Université de Sherbrooke, Université de Sherbrooke, 3IT, Université de Sherbrooke, Novalgo Inc., Université de Sherbrooke, Université de Sherbrooke, CIMS/CRCHUS, 3IT, Université de Sherbrooke, Université de Sherbrooke, Université de Sherbrooke, Université de Sherbrooke, 3IT, Université de Sherbrooke (Canada); and others

    2016-08-15

    Purpose: LabPET II is a new generation APD-based PET scanner designed to achieve sub-mm spatial resolution using truly pixelated detectors and highly integrated parallel front-end processing electronics. Methods: The basic element uses a 4×8 array of 1.12×1.12 mm{sup 2} Lu{sub 1.9}Y{sub 0.1}SiO{sub 5}:Ce (LYSO) scintillator pixels with one-to-one coupling to a 4×8 pixelated monolithic APD array mounted on a ceramic carrier. Four detector arrays are mounted on a daughter board carrying two flip-chip, 64-channel, mixed-signal, application-specific integrated circuits (ASIC) on the backside interfacing to two detector arrays each. Fully parallel signal processing was implemented in silico by encoding time and energy information using a dual-threshold Time-over-Threshold (ToT) scheme. The self-contained 128-channel detector module was designed as a generic component for ultra-high resolution PET imaging of small to medium-size animals. Results: Energy and timing performance were optimized by carefully setting ToT thresholds to minimize the noise/slope ratio. ToT spectra clearly show resolved 511 keV photopeak and Compton edge with ToT resolution well below 10%. After correction for nonlinear ToT response, energy resolution is typically 24±2% FWHM. Coincidence time resolution between opposing 128-channel modules is below 4 ns FWHM. Initial imaging results demonstrate that 0.8 mm hot spots of a Derenzo phantom can be resolved. Conclusion: A new generation PET scanner featuring truly pixelated detectors was developed and shown to achieve a spatial resolution approaching the physical limit of PET. Future plans are to integrate a small-bore dedicated mouse version of the scanner within a PET/CT platform.

  7. Compact and high-sensitivity 100-Gb/s (4 × 25 Gb/s) APD-ROSA with a LAN-WDM PLC demultiplexer.

    Science.gov (United States)

    Yoshimatsu, Toshihide; Nada, Masahiro; Oguma, Manabu; Yokoyama, Haruki; Ohno, Tetsuichiro; Doi, Yoshiyuki; Ogawa, Ikuo; Takahashi, Hiroshi; Yoshida, Eiji

    2012-12-10

    We demonstrate an integrated 100 GbE receiver optical sub-assembly (ROSA) that incorporates a monolithic four-channel avalanche photodiode (APD) array and a planer lightwave circuit (PLC) based LAN-WDM demultiplexer. A record minimum receiver sensitivity of -20 dBm and 50-km error-free SMF transmission without an optical amplifier have been achieved.

  8. The current status of eye lens dose measurement in interventional cardiology personnel in Thailand.

    Science.gov (United States)

    Krisanachinda, Anchali; Srimahachota, Suphot; Matsubara, Kosuke

    2017-06-01

    Workers involved in interventional cardiology procedures receive high eye lens doses if radiation protection tools are not properly utilized. Currently, there is no suitable method for routine measurement of eye dose. In Thailand, the eye lens equivalent doses in terms of Hp(3) of the interventional cardiologists, nurses, and radiographers participating in interventional cardiology procedures have been measured at 12 centers since 2015 in the pilot study. The optically stimulated luminescence (OSL) dosimeter was used for measurement of the occupational exposure and the eye lens dose of 42 interventional cardiology personnel at King Chulalongkorn Memorial Hospital as one of the pilot centers. For all personnel, it is recommended that a first In Light OSL badge is placed at waist level and under the lead apron for determination of Hp(10); a second badge is placed at the collar for determination of Hp(0.07) and estimation of Hp(3). Nano Dots OSL dosimeter has been used as an eye lens dosimeter for 16 interventional cardiology personnel, both with and without lead-glass eyewear. The mean effective dose at the body, equivalent dose at the collar, and estimated eye lens dose were 0.801, 5.88, and 5.70 mSv per year, respectively. The mean eye lens dose measured by the Nano Dots dosimeter was 8.059 mSv per year on the left eye and 3.552 mSv per year on the right eye. Two of 16 interventional cardiologists received annual eye lens doses on the left side without lead glass that were higher than 20 mSv per year, the new eye lens dose limit as recommended by ICRP with the risk of eye lens opacity and cataract.

  9. Photon energy response of an aluminum oxide TLD environmental dosimeter

    International Nuclear Information System (INIS)

    Olsher, R.H.

    1992-01-01

    Because of aluminum oxide's significant advantage in sensitivity (about a factor of 30) over LiF, minimal fading characteristics and ease of processing, aluminum oxide thermoluminescent dosimeters (TLDS) are being phased in at Los alamos for environmental monitoring of photon radiation. The new environmental dosimeter design consists of a polyethylene holder, about 0. 5 cm thick, loaded with a stack of four aluminum oxide TLD chips, each 1 mm thick and 5 mm in diameter. As part of the initial evaluation of the new design, the photon energy response of the dosimeter was calculated over the range from 10 keV to 1 MeV. Specific goals of the analysis included the determination of individual chip response in the stack, assessment of the response variation due to TLD material (i.e., LiF versus A1 2 O 3 ), and the effect of copper filtration in flattening the response

  10. Training of maintenance personnel

    International Nuclear Information System (INIS)

    Rabouhams, J.

    1986-01-01

    This lecture precises the method and means developed by EDF to ensure the training of maintenance personnel according to their initial educational background and their experience. The following points are treated: General organization of the training for maintenance personnel in PWR and GCR nuclear power stations and in Creys Malville fast breeder reactor; Basic nuclear training and pedagogical aids developed for this purpose; Specific training and training provided by contractors; complementary training taking into account the operation experience and feedback; Improvement of velocity, competence and safety during shut-down operations by adapted training. (orig.)

  11. Passive dosimetry: introduction of a new dosimeter based on OSL technology

    International Nuclear Information System (INIS)

    Archambault, V.; Le Roy, G.; Prugnaud, B.

    2005-01-01

    A new passive dosimeter based on OSL technology has been introduced on the French market. In this article are described: the technology and the material on which this new detector relied, the dosimeter itself. (author)

  12. Angular dependence of the nanoDot OSL dosimeter

    International Nuclear Information System (INIS)

    Kerns, James R.; Kry, Stephen F.; Sahoo, Narayan; Followill, David S.; Ibbott, Geoffrey S.

    2011-01-01

    Purpose: Optically stimulated luminescent detectors (OSLDs) are quickly gaining popularity as passive dosimeters, with applications in medicine for linac output calibration verification, brachytherapy source verification, treatment plan quality assurance, and clinical dose measurements. With such wide applications, these dosimeters must be characterized for numerous factors affecting their response. The most abundant commercial OSLD is the InLight/OSL system from Landauer, Inc. The purpose of this study was to examine the angular dependence of the nanoDot dosimeter, which is part of the InLight system. Methods: Relative dosimeter response data were taken at several angles in 6 and 18 MV photon beams, as well as a clinical proton beam. These measurements were done within a phantom at a depth beyond the build-up region. To verify the observed angular dependence, additional measurements were conducted as well as Monte Carlo simulations in MCNPX. Results: When irradiated with the incident photon beams parallel to the plane of the dosimeter, the nanoDot response was 4% lower at 6 MV and 3% lower at 18 MV than the response when irradiated with the incident beam normal to the plane of the dosimeter. Monte Carlo simulations at 6 MV showed similar results to the experimental values. Examination of the results in Monte Carlo suggests the cause as partial volume irradiation. In a clinical proton beam, no angular dependence was found. Conclusions: A nontrivial angular response of this OSLD was observed in photon beams. This factor may need to be accounted for when evaluating doses from photon beams incident from a variety of directions.

  13. Comparison between two kind of power circuits for personal dosimeter

    International Nuclear Information System (INIS)

    Liu Zhengshan; Deng Changming; Guo Zhanjie

    2002-01-01

    Personal Dosimeter is commonly requested using battery for its power supply, and hope the battery life is long. Also with the fall of battery voltage, some performance of instrument as well as drop, Reasonable supply design can protract the battery life. The author introduces two method: power supply with battery directly and supply used power chip conversion. Combine personal dosimeter, the authors carried comparison for battery life, power consumption, cost and volume. Based on the comparison result and instrument fact request, one can choose method of power circuit

  14. Locations of criticality alarms and nuclear accident dosimeters at Hanford

    International Nuclear Information System (INIS)

    1992-08-01

    Hanford facilities that contain fissionable materials capable of achieving critical mass are monitored with nuclear accident dosimeters (NADS) in compliance with the requirements of DOE Order 5480.11, Chapter XI, Section 4.c. (DOE 1988). The US Department of Energy (DOE) Richland Field Office (RL) has assigned the responsibility for maintaining and evaluating the Hanford NAD system to the Instrumentation and External Dosimetry (I ampersand ED) Section of Pacific Northwest Laboratory's (PNL's) Health Physics Department. This manual provides a description of the Hanford NAD, criteria and instructions for proper NAD placement, and the locations of these dosimeters onsite

  15. Neutron personnel dosimetry considerations for fusion reactors

    International Nuclear Information System (INIS)

    Barton, T.P.; Easterly, C.E.

    1979-07-01

    The increasing development of fusion reactor technology warrants an evaluation of personnel neutron dosimetry systems to aid in the concurrent development of a radiation protection program. For this reason, current state of knowledge neutron dosimeters have been reviewed with emphasis placed on practical utilization and the problems inherent in each type of dosimetry system. Evaluations of salient parameters such as energy response, latent image instability, and minimum detectable dose equivalent are presented for nuclear emulsion films, track etch techniques, albedo and other thermoluminescent dosimetry techniques, electrical conductivity damage effects, lyoluminescence, thermocurrent, and thermally stimulated exoelectron emission. Brief summaries of dosimetry regulatory requirements and intercomparison study results help to establish compliance and recent trends, respectively. Spectrum modeling data generated by the Neutron Physics Division of Oak Ridge National Laboratory for the Princeton Tokamak Fusion Test Reactor (TFTR) Facility have been analyzed by both International Commission on Radiological Protection fluence to dose conversion factors and an adjoint technique of radiation dosimetry, in an attempt to determine the applicability of current neutron dosimetry systems to deuterium and tritium fusion reactor leakage spectra. Based on the modeling data, a wide range of neutron energies will probably be present in the leakage spectra of the TFTR facility, and no appreciable risk of somatic injury to occupationally exposed workers is expected. The relative dose contributions due to high energy and thermal neutrons indicate that neutron dosimetry will probably not be a serious limitation in the development of fusion power

  16. Current personnel dosimetry practices at DOE facilities

    International Nuclear Information System (INIS)

    Fix, J.J.

    1981-05-01

    Only three parameters were included in the personnel occupational exposure records by all facilities. These are employee name, social security number, and whole body dose. Approximate percentages of some other parameters included in the record systems are sex (50%), birthdate (90%), occupation (26%), previous employer radiation exposure (74%), etc. Statistical analysis of the data for such parameters as sex versus dose distribution, age versus dose distribution, cumulative lifetime dose, etc. was apparently seldom done. Less than 50% of the facilities reported having formal documentation for either the dosimeter, records system, or reader. Slightly greater than 50% of facilities reported having routine procedures in place. These are considered maximum percentages because some respondents considered computer codes as formal documentation. The repository receives data from DOE facilities regarding the (a) distribution of annual whole body doses, (b) significant internal depositions, and (c) individual doses upon termination. It is expected that numerous differences exist in the dose data submitted by the different facilities. Areas of significant differences would likely include the determination of non-measurable doses, the methods used to determine previous employer radiation dose, the methods of determining cumulative radiation dose, and assessment of internal doses. Undoubtedly, the accuracy of the different dosimetry systems, especially at low doses, is very important to the credibility of data summaries (e.g., man-rem) provided by the repository

  17. Personnel photographic film dosimetry

    International Nuclear Information System (INIS)

    Keirim-Markus, I.B.

    1981-01-01

    Technology of personnel photographic film dosimetry (PPD) based on the photographic effect of ionizing radiation is described briefly. Kinds of roentgen films used in PPD method are enumerated, compositions of a developer and fixing agents for these films are given [ru

  18. Harmonious personnel scheduling

    NARCIS (Netherlands)

    Fijn van Draat, Laurens; Post, Gerhard F.; Veltman, Bart; Winkelhuijzen, Wessel

    2006-01-01

    The area of personnel scheduling is very broad. Here we focus on the ‘shift assignment problem’. Our aim is to discuss how ORTEC HARMONY handles this planning problem. In particular we go into the structure of the optimization engine in ORTEC HARMONY, which uses techniques from genetic algorithms,

  19. Nuclear Test Personnel Review

    Science.gov (United States)

    FOIA Electronic Reading Room Privacy Impact Assessment DTRA No Fear Act Reporting Nuclear Test Personnel Review NTPR Fact Sheets NTPR Radiation Dose Assessment Documents US Atmospheric Nuclear Test History Documents US Underground Nuclear Test History Reports NTPR Radiation Exposure Reports Enewetak

  20. Tracking and Monitoring with Dosimeter-Enabled ARG-US RFID System - 12009

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J.; Lee, H.; De Lurgio, P.; Kearney, C.M.; Craig, B.; Soos, I.H.; Tsai, H.; Liu, Y. [Argonne National Laboratory, Argonne, IL 60439 (United States); Shuler, J. [U.S. Department of Energy, Washington, D.C. 20585 (United States)

    2012-07-01

    Automated monitoring and tracking of materials with radio frequency identification (RFID) technology can significantly improve both the operating efficiency of radiological facilities and the application of the ALARA (as low as reasonably achievable) principle in them. One such system, called ARG-US, has been developed by Argonne National Laboratory for the U.S. Department of Energy (DOE) Packaging and Certification Program to use in managing sensitive nuclear and radioactive materials. Several ARG-US systems are in various stages of deployment and advanced testing across DOE sites. ARG-US utilizes sensors in the tags to continuously monitor the state of health of the packaging and promptly disseminates alarms to authorized users. In conjunction with global positioning system (GPS) tracking provided by TRANSCOM, the system can also monitor and track packages during transport. A compact dosimeter has been incorporated in the ARG-US tags via an onboard universal asynchronous receiver/transmitter interface. The detector has a wide measurement range for gamma radiation - from 0.1 mSv/h to 8 Sv/h. The detector is able to generate alarms for both high and low radiation and for a high cumulative dose. In a large installation, strategically located dosimeter-enabled tags can yield an accurate, real-time, 2D or 3D dose field map that can be used to enhance facility safety, security, and safeguards. This implementation can also lead to a reduced need for manned surveillance and reduced exposure of personnel to radiation, consistent with the ALARA principle at workplaces. (authors)

  1. Automated dose estimation for lost or damaged dosimeters

    International Nuclear Information System (INIS)

    Thompson, W.L.; Deininger, R.J.

    1988-01-01

    This paper reports that some dosimetry vendors will compute doses for their customers' lost/damaged dosimeters based upon an average of recent dosimeter readings. However, the vendors usually require authorization from the customer for each such occurrence. Therefore, the tedious task of keeping track of the overdue status of each missing dosimeter and constantly notifying the vendor is still present. Also, depending on the monthly variability of a given person's doses, it may be more valid to use the employee's average dose, his/her highest dose over a recent period, an average dose of other employees with similar job duties for that period, or the maximum permissible dose. Thus, the task of estimating doses for lost/damaged dosimeters cannot be delegated to dosimetry vendor. Instead, the radiation safety department must sue the data supplied by the vendor as input for performing estimates. The process is performed automatically at the Medical Center Hospital of Vermont using a personal computer and a relational database

  2. Sugar dosimeters. Part 1. State of the art

    International Nuclear Information System (INIS)

    Peimel-Stuglik, Z.

    2008-01-01

    A review of the literature dealing with the possibility of using sugars, in particular sucrose, as dosimetric material is presented. All methods involved were divided according to analytical techniques used in dosimetric signal measurements (polarimetry, spectrophotometry and electron paramagnetic resonance - EPR). Double-signal sugar dosimeters (EPR + spectrophotometry) are also described. (author) [pl

  3. Validation of an Innovative Satellite-Based UV Dosimeter

    Science.gov (United States)

    Morelli, Marco; Masini, Andrea; Simeone, Emilio; Khazova, Marina

    2016-08-01

    We present an innovative satellite-based UV (ultraviolet) radiation dosimeter with a mobile app interface that has been validated by exploiting both ground-based measurements and an in-vivo assessment of the erythemal effects on some volunteers having a controlled exposure to solar radiation.Both validations showed that the satellite-based UV dosimeter has a good accuracy and reliability needed for health-related applications.The app with this satellite-based UV dosimeter also includes other related functionalities such as the provision of safe sun exposure time updated in real-time and end exposure visual/sound alert. This app will be launched on the global market by siHealth Ltd in May 2016 under the name of "HappySun" and available both for Android and for iOS devices (more info on http://www.happysun.co.uk).Extensive R&D activities are on-going for further improvement of the satellite-based UV dosimeter's accuracy.

  4. The passive radon-thoron discriminative dosimeter for practical use

    International Nuclear Information System (INIS)

    Doi, Masahiro; Kobayashi, Sadayoshi

    1994-01-01

    A passive radon-thoron discriminative dosimeter for practical use has been developed. The body of the practical R-T dosimeter is made of two hemispheric diffusion chambers of carbonized plastic whose diameters are 110 mm and 70 mm, respectively. These diameters are determined to improve the detection efficiency of radon as well as thoron and also the discrimination ratio of radon to thoron. Inner surface of the detector housing is smooth and free from electrified charge to assure the uniform deposition of radon and thoron progeny, because the detector housing is molded out of carbonized plastic as an anti-static material. In addition, structure of an air inlet has improved to contact more tightly with a glass fiber filter to prevent dust from entering the detector housing. The air inlet of the detector housing is also covered with a half-cutted hemispherical windbreak to protect the glass fiber filter from weathering and to stabilize the influence of convectional air flow on the radon and thoron entry rate into two hemispherical diffusion chambers of the dosimeter. The results of calibration exercises showed that the lower detection limit of radon and thoron concentrations were estimated to be 5.1 Bqm -3 and 7.9 Bqm -3 respectively in 2 months exposure. And an interim measurement in the concrete cellar proved that the practical R-T dosimeter has enough specifications to be used in the large-scale radon-thoron discriminative survey. (author)

  5. Fast neutron dosimeter with wide base silicon diode

    International Nuclear Information System (INIS)

    Ma Lu

    1986-01-01

    This paper briefly introduces a wide base silicon diode fast neutron dosimeter with wide measuring range and good energy response to fast neutron. It is suitable to be used to detect fast neutrons in the mixed field of γ-ray, thermal neutrons and fast neutrons

  6. Dosimetry of blood irradiation using an alanine/ESR dosimeter

    International Nuclear Information System (INIS)

    Chen, F.; Covas, D.T.; Baffa, O.

    2001-01-01

    A batch of 80 DL-alanine dosimeters was supplied to Hemocentro of the Hospital and Clinics of Faculdade de Medicina de Ribeirao Preto (HC-FMRP) SP, Brazil for the purpose of quality control of the radiation dose delivered to blood bags. The irradiation was made using two (40x40) cm 2 parallel opposed radiation fields each with 80 cm of source to surface distance in the Radiotherapy Section of HC-FMRP with the 60 Co teletherapy unit. The calculated radiation absorbed dose at the center of the box was 20 Gy. The dosimeter readings were performed using a Varian E-4 ESR Spectrometer operating in X-band. For the 80 dosimeters and over the irradiation volume throughout a blood bag, the minimum and maximum doses were 14 and 23 Gy, respectively. The mean dose was (18±2) Gy (1σ), and the coefficient of variability was 11.1%. Alanine dosimeters demonstrated easy handling, good precision and adequate sensitivity for this application

  7. Calibration results obtained with Liulin-4 type dosimeters

    Czech Academy of Sciences Publication Activity Database

    Dacheva, T.; Tomova, B.; Matviichuka, Y.; Dimitrova, P.; Lemaireb, J.; Gregoirec, G.; Cyamukunguc, M.; Schmitzc, H.; Fujitakad, K.; Uchihorid, Y.; Kitamurad, H.; Reitze, G.; Beaujeanf, R.; Petrovg, V.; Shurshakovg, V.; Benghing, V.; Spurný, František

    2002-01-01

    Roč. 30, č. 4 (2002), s. 917-925 ISSN 0273-1177 Institutional research plan: CEZ:AV0Z1048901 Keywords : CERN high-energy reference field * detector * dosimeter Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.448, year: 2002

  8. Portable battery-free charger for radiation dosimeters

    International Nuclear Information System (INIS)

    Manning, F.W.

    1984-01-01

    This invention is a novel portable charger for dosimeters of the electrometer type. The charger does not require batteries or piezoelectric crystals and is of rugged construction. In a preferred embodiment, the charge includes a housing which carries means for mounting a dosimeter to be charged. The housing also includes contact means for impressing a charging voltage across the mounted dosimeter. Also, the housing carries a trigger for operating a charging system mounted in the housing. The charging system includes a magnetic loop including a permanent magnet for establishing a magnetic field through the loop. A segment of the loop is coupled to the trigger for movement thereby to positions opening and closing the loop. A coil inductively coupled with the loop generates coil-generated voltage pulses when the trigger is operated to open and close the loop. The charging system includes an electrical circuit for impressing voltage pulses from the coil across a capacitor for integrating the pulses and applying the resulting integrated voltage across the above-mentioned contact means for charging the dosimeter

  9. Portable battery-free charger for radiation dosimeters

    Science.gov (United States)

    Manning, Frank W.

    1984-01-01

    This invention is a novel portable charger for dosimeters of the electrometer type. The charger does not require batteries or piezoelectric crystals and is of rugged construction. In a preferred embodiment, the charge includes a housing which carries means for mounting a dosimeter to be charged. The housing also includes contact means for impressing a charging voltage across the mounted dosimeter. Also, the housing carries a trigger for operating a charging system mounted in the housing. The charging system includes a magnetic loop including a permanent magnet for establishing a magnetic field through the loop. A segment of the loop is coupled to the trigger for movement thereby to positions opening and closing the loop. A coil inductively coupled with the loop generates coil-generated voltage pulses when the trigger is operated to open and close the loop. The charging system includes an electrical circuit for impressing voltage pulses from the coil across a capacitor for integrating the pulses and applying the resulting integrated voltage across the above-mentioned contact means for charging the dosimeter.

  10. Monte Carlo simulation experiments on box-type radon dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Jamil, Khalid, E-mail: kjamil@comsats.edu.pk; Kamran, Muhammad; Illahi, Ahsan; Manzoor, Shahid

    2014-11-11

    Epidemiological studies show that inhalation of radon gas ({sup 222}Rn) may be carcinogenic especially to mine workers, people living in closed indoor energy conserved environments and underground dwellers. It is, therefore, of paramount importance to measure the {sup 222}Rn concentrations (Bq/m{sup 3}) in indoors environments. For this purpose, box-type passive radon dosimeters employing ion track detector like CR-39 are widely used. Fraction of the number of radon alphas emitted in the volume of the box type dosimeter resulting in latent track formation on CR-39 is the latent track registration efficiency. Latent track registration efficiency is ultimately required to evaluate the radon concentration which consequently determines the effective dose and the radiological hazards. In this research, Monte Carlo simulation experiments were carried out to study the alpha latent track registration efficiency for box type radon dosimeter as a function of dosimeter’s dimensions and range of alpha particles in air. Two different self developed Monte Carlo simulation techniques were employed namely: (a) Surface ratio (SURA) method and (b) Ray hitting (RAHI) method. Monte Carlo simulation experiments revealed that there are two types of efficiencies i.e. intrinsic efficiency (η{sub int}) and alpha hit efficiency (η{sub hit}). The η{sub int} depends upon only on the dimensions of the dosimeter and η{sub hit} depends both upon dimensions of the dosimeter and range of the alpha particles. The total latent track registration efficiency is the product of both intrinsic and hit efficiencies. It has been concluded that if diagonal length of box type dosimeter is kept smaller than the range of alpha particle then hit efficiency is achieved as 100%. Nevertheless the intrinsic efficiency keeps playing its role. The Monte Carlo simulation experimental results have been found helpful to understand the intricate track registration mechanisms in the box type dosimeter. This paper

  11. Experimental characterization of the 192 channel Clear-PEM frontend ASIC coupled to a multi-pixel APD readout of LYSO:Ce crystals

    International Nuclear Information System (INIS)

    Albuquerque, Edgar; Bexiga, Vasco; Bugalho, Ricardo; Carrico, Bruno; Ferreira, Claudia S.; Ferreira, Miguel; Godinho, Joaquim; Goncalves, Fernando; Leong, Carlos; Lousa, Pedro; Machado, Pedro; Moura, Rui; Neves, Pedro; Ortigao, Catarina; Piedade, Fernando; Pinheiro, Joao F.; Rego, Joel; Rivetti, Angelo; Rodrigues, Pedro; Silva, Jose C.

    2009-01-01

    In the framework of the Clear-PEM project for the construction of a high-resolution scanner for breast cancer imaging, a very compact and dense frontend electronics system has been developed for readout of multi-pixel S8550 Hamamatsu APDs. The frontend electronics are instrumented with a mixed-signal Application-Specific Integrated Circuit (ASIC), which incorporates 192 low-noise charge pre-amplifiers, shapers, analog memory cells and digital control blocks. Pulses are continuously stored in memory cells at clock frequency. Channels above a common threshold voltage are readout for digitization by off-chip free-sampling ADCs. The ASIC has a size of 7.3x9.8mm 2 and was implemented in a AMS 0.35μm CMOS technology. In this paper the experimental characterization of the Clear-PEM frontend ASIC, reading out multi-pixel APDs coupled to LYSO:Ce crystal matrices, is presented. The chips were mounted on a custom test board connected to six APD arrays and to the data acquisition system. Six 32-pixel LYSO:Ce crystal matrices coupled on both sides to APD arrays were readout by two test boards. All 384 channels were operational. The chip power consumption is 660 mW (3.4 mW per channel). A very stable behavior of the chip was observed, with an estimated ENC of 1200-1300e - at APD gain 100. The inter-channel noise dispersion and mean baseline variation is less than 8% and 0.5%, respectively. The spread in the gain between different channels is found to be 1.5%. Energy resolution of 16.5% at 511 keV and 12.8% at 662 keV has been measured. Timing measurements between the two APDs that readout the same crystal is extracted and compared with detailed Monte Carlo simulations. At 511 keV the measured single photon time RMS resolution is 1.30 ns, in very good agreement with the expected value of 1.34 ns.

  12. Comprehensive Angular Response Study of LLNL Panasonic Dosimeter Configurations and Artificial Intelligence Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Stone, D. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-06-30

    In April of 2016, the Lawrence Livermore National Laboratory External Dosimetry Program underwent a Department of Energy Laboratory Accreditation Program (DOELAP) on-site assessment. The assessment reported a concern that the study performed in 2013 Angular Dependence Study Panasonic UD-802 and UD-810 Dosimeters LLNL Artificial Intelligence Algorithm was incomplete. Only the responses at ±60° and 0° were evaluated and independent data from dosimeters was not used to evaluate the algorithm. Additionally, other configurations of LLNL dosimeters were not considered in this study. This includes nuclear accident dosimeters (NAD) which are placed in the wells surrounding the TLD in the dosimeter holder.

  13. Calibration of dosimeters at 80-120 keV electron irradiation

    DEFF Research Database (Denmark)

    Miller, A.; Helt-Hansen, J.

    to calibrate thin-film dosimeters (Risø B3 and alanine films) by irradiation at the 80–120 keV electron accelerators. This calibration was compared to a 10MeV calibration, and we show that the radiation response of the dosimeter materials (the radiation chemical yield) is constant at these irradiation energies....... However, dose gradients within the dosimeters, when it is irradiated at low electron energies,mean that calibration function here will depend on both irradiation energy and the required effective point of measurement of the dosimeter. These are general effects that apply to any dosimeter that has a non...

  14. Modernization of personnel training

    International Nuclear Information System (INIS)

    Haferburg, M.; Rehn, H.

    1997-01-01

    Personnel training in German nuclear power plants adheres to high standards complying with government regulations. The development of PC technology allows the introduction of new training methods, e.g. computer based training (CBT), as well as their integration into existing systems. In Germany, the operators of nuclear power plants have developed their own computer based standards with a screen design, a hardware platform and an assessment standard. 25% of the theoretical training of the shift personnel is covered by CBT. The CBT-Programmes offer multimedia features: videos, photographs, sound, graphs and switching diagrams of existing systems, practice oriented simulations and 3-D animations. Interaction is the most important attribute of an efficient self-learning-programme. A typical example of such an appropriate theme is the CBT-Lesson ''Pressure Surges in Pipes and Components of Power Plants''. (author)

  15. Ionizing radiation M.O.S. dosimeters: sensibility and stability

    International Nuclear Information System (INIS)

    Gessinn, F.

    1993-12-01

    This thesis is a contribution to the study of the ionizing radiation responsivity of P.O.M.S. dosimeters. Unlike the development of processing hardening techniques, our works goal were to increase, on the one hand, the M.O.S. dosimeters sensitivity in order to detect small radiation doses and on the other hand, the stability with time and temperature of the devices, to minimize the absorbed-dose estimation errors. With this aim in mind, an analysis of all processing parameters has been carried out: the M.O.S. dosimeter sensitivity is primarily controlled by the gate oxide thickness and the irradiation electric field. Thus, P.M.O.S. transistors with 1 and 2 μm thick silica layers have been fabricated for our experiments. The radiation response of our devices in the high-field mode satisfactorily fits a D ox 2 power law. The maximum sensitivity achieved (9,2 V/Gy for 2μm devices) is close to the ideal value obtained when considering only an unitary carrier-trapping level, and allows to measure about 10 -2 Gy radiation doses. Read-time stability has been evaluated under bias-temperature stress conditions: experiments underscore slow fading, corresponding to 10 -3 Gy/h. The temperature response has also been studied: the analytical model we have developed predicts M.O.S. transistors threshold voltage variations over the military specifications range [-50 deg. C, + 150 deg. C]. Finally, we have investigated the possibilities of irradiated dosimeters thermal annealing for reusing. It appears clearly that radiation-induced damage annealing is strongly gate bias dependent. Furthermore, dosimeters radiation sensitivity seems not to be affected by successive annealings. (author). 146 refs., 58 figs., 9 tabs

  16. Do Military Personnel Patent

    Science.gov (United States)

    2016-12-01

    following questions: In what fields are military personnel most likely to patent, and how do demographics, such as age, race, and gender , along with...technologies, which have transformed how the United States wages war. DARPA continues to develop new technologies and capabilities for the U.S. military today...build the European navies so it instead decided to utilize an innovative ship design to exploit a gap specific to the British Royal Navy. The six

  17. Employment of security personnel

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    If a company or institution hires personnel of a security service company to protect its premises, this kind of employment does not mean the company carries on temporary employment business. Within the purview of section 99, sub-section 1 of the BetrVG (Works Constitution Act), the security service personnel is not 'employed' in the proper sense even if the security tasks fulfilled by them are done at other times by regular employees of the company or institution. The court decision also decided that the Works Council need not give consent to employment of foreign security personnel. The court decision was taken for settlement of court proceedings commenced by Institute of Plasma Physics in Garching. In his comments, W. Hunold accedes to the court's decision and discusses the underlying reasons of this decision and of a previous ruling in the same matter by putting emphasis on the difference between a contract for services and a contract for work, and a contract for temporary employment. The author also discusses the basic features of an employment contract. (orig./HP) [de

  18. Automatic personnel contamination monitor

    International Nuclear Information System (INIS)

    Lattin, Kenneth R.

    1978-01-01

    United Nuclear Industries, Inc. (UNI) has developed an automatic personnel contamination monitor (APCM), which uniquely combines the design features of both portal and hand and shoe monitors. In addition, this prototype system also has a number of new features, including: micro computer control and readout, nineteen large area gas flow detectors, real-time background compensation, self-checking for system failures, and card reader identification and control. UNI's experience in operating the Hanford N Reactor, located in Richland, Washington, has shown the necessity of automatically monitoring plant personnel for contamination after they have passed through the procedurally controlled radiation zones. This final check ensures that each radiation zone worker has been properly checked before leaving company controlled boundaries. Investigation of the commercially available portal and hand and shoe monitors indicated that they did not have the sensitivity or sophistication required for UNI's application, therefore, a development program was initiated, resulting in the subject monitor. Field testing shows good sensitivity to personnel contamination with the majority of alarms showing contaminants on clothing, face and head areas. In general, the APCM has sensitivity comparable to portal survey instrumentation. The inherit stand-in, walk-on feature of the APCM not only makes it easy to use, but makes it difficult to bypass. (author)

  19. Electronic Official Personnel Folder System

    Data.gov (United States)

    US Agency for International Development — The eOPF is a digital recreation of paper personnel folder that stores electronic personnel data spanning an individual's Federal career. eOPF allows employees to...

  20. Fast neutron personnel dosimetry by CR-39 plastics a new electrochemical etching procedure

    International Nuclear Information System (INIS)

    Djeffal, S.

    1984-07-01

    In the first part of this work a brief description of solid state nuclear track detectors, the principles of track registration and the different reading techniques are given. In the experimental part of the present work we systematically analysed different etching procedures and set a new electrochemical etching method, which enables us to develop a new fast neutron dosimeter. This fast neutron dosimeter makes possible the measurement of low neutron doses in the energy range from 10 Kev to 20 Mev with a reasonably flat energy response. These new developments are very attractive in personnel neutron dosimetry where nuclear emulsions are still used despite their insensitivity to neutron energies down to 500 Kev (i.e. the energy range one often encounters around nuclear facilities)

  1. Water-equivalent one-dimensional scintillating fiber-optic dosimeter for measuring therapeutic photon beam

    International Nuclear Information System (INIS)

    Moon, Jinsoo; Won Jang, Kyoung; Jae Yoo, Wook; Han, Ki-Tek; Park, Jang-Yeon; Lee, Bongsoo

    2012-01-01

    In this study, we fabricated a one-dimensional scintillating fiber-optic dosimeter, which consists of 9 scintillating fiber-optic dosimeters, septa, and PMMA blocks for measuring surface and percentage depth doses of a therapeutic photon beam. Each dosimeter embedded in the 1-D scintillating fiber-optic dosimeter is composed of square type organic scintillators and plastic optical fibers. Also black PVC films are used as septa to minimize cross-talk between the scintillating fiber-optic dosimeters. To construct a dosimeter system, a 1-D scintillating fiber-optic dosimeter and a CMOS image sensor were combined with 20 m-length plastic optical fibers. Using the dosimeter system, we measured surface and percentage depth doses of 6 and 15 MV photon beams and compared the results with those of EBT films and an ionization chamber. - Highlights: ► Fabrication of a one-dimensional scintillating fiber-optic dosimeter. ► The one-dimensional scintillating fiber-optic dosimeter has 9 scintillating fiber-optic dosimeters. ► Measurements of surface and percentage depth doses of a therapeutic photon beam. ► The results were compared with those of EBT films and an ionization chamber.

  2. Evaluation of the implementation and use of active personal dosimeters for neutrons in Brazil

    International Nuclear Information System (INIS)

    Castro B, C. P.; Wagner P, W.; De Souza P, K. C.

    2014-08-01

    This work was conducted through of a field research based on a questionnaire sent to users of active personal dosimeters. A retrospective study of the last six years was also carried out of the services in the Neutron Metrology Laboratory (2008-2013) referent to the active personal dosimeters, taking into consideration the standards ISO-8529-3 and IEC-61526. The active personal dosimeters are defined as any instrument of individual monitoring with direct reading capacity, used by individuals exposed to ionizing radiation fields. Through research was verified that the active personal dosimeters work associated with other dosimeter types. Considering all dosimeters declared in the questionnaire, only two dosimeters (MGP brand Dmc 2000-GN model and the brand ATOMTEX model AT2503A) have conformity declaration with the international standard IEC-61526: 2005 reported by the manufacturers. (author)

  3. Eleventh ORNL personnel dosimetry intercomparison study, May 22-23, 1985

    International Nuclear Information System (INIS)

    Swaja, R.E.; Oyan, R.; Sims, C.S.

    1986-07-01

    The Eleventh Personnel Dosimetry Intercomparison Study was conducted at the Oak Ridge National Laboratory (ORNL) during May 22-23, 1985. Dosimeter badges from 44 participating organizations were mounted on Lucite block phantoms and exposed to four mixed-radiation fields with neutron dose equivalents around 5 mSv and gamma dose equivalents between 0.1 and 0.7 mSv. Results of this study indicated that no participants had difficulty obtaining measurable indication of neutron exposure at the provided dose equivalent levels, and very few had difficulty obtaining indication of gamma exposure at dose equivalents as low as 0.10 mSv. Average neutron results for all dosimeter types were within 20% of reference values with no obvious spectrum dependence. Different dosimeter types (albedo, direct interaction TLD, film, recoil track, and combination albedo-track) with 10 or more reported measurements provided average results within 35% of reference values for all spectra. With regard to precision, about 80% of the reported neutron results had single standard deviations within 10% at the means which indicates that precision is not a problem relative to accuracy for most participants. Average gamma results were greater than reference values by factors of 1.07 to 1.52 for the four exposures with TLD systems being more accurate than film. About 80% of all neutron results and 67% of all gamma results met regulatory standards for measurement accuracy and approximately 70% of all neutron data satisfied national dosimetry accreditation criteria for accuracy plus precision. In general, neutron dosimeter performance observed in this intercomparison was much improved compared to that observed in the prior studies while gamma dosimeter performance was about the same

  4. CARE-HHH-APD Workshop on Finalizing the Roadmap for the Upgrade of the CERN and GSI Accelerator Complex

    CERN Document Server

    Zimmermann, Frank; BEAM'07; BEAM 2007; Finalizing the Roadmap for the Upgrade of the LHC and GSI Accelerator Complex

    2008-01-01

    This report contains the Proceedings of the CARE-HHH-APD Event BEAM’07, “Finalizing the Roadmap for the Upgrade of the CERN & GSI Accelerator Complex,” which was held at CERN in Geneva, Switzerland, from 1 to 5 October 2007. BEAM’07 was primarily devoted to beam dynamics limitations for the two, or three, alternative baseline scenarios of the LHC luminosity upgrade and to critical design choices for the upgrade of the LHC injector complex at CERN and for the FAIR complex at GSI. It comprised five parts: (1) a Mini-Workshop on LHC+ Beam Performance, (2) a CERN-GSI Meeting on Collective Effects, (3) the Francesco Ruggiero Memorial Symposium, (4) a Mini-Workshop on the LHC Injectors Upgrade, and (5) the BEAM’07 Summaries. Topics addressed in the first mini-workshop of BEAM’07 ranged from the luminosity performance reach of the upgraded LHC in different scenarios, over the generation and stability of the future LHC beams, the turnaround time, beam–beam effects, luminosity levelling methods, and ...

  5. Joint CARE-ELAN, CARE-HHH-APD, and EUROTEV-WP3 Workshop on Electron Cloud Clearing

    CERN Document Server

    Scandale, Walter; Schulte, D; Zimmermann, F; Electron Cloud Effects and Technological Consequences; ECL2

    2007-01-01

    This report contains the Proceedings of the joint CARE-HHH-APD, CARE-ELAN, and EUROTEV-WP3 Mini-Workshop on 'Electron Cloud Clearing - Electron Cloud and Technical Consequences', "ECL2", held at CERN in Geneva, Switzerland, 1-2 March 2007). The ECL2 workshop explored novel technological remedies against electron-cloud formation in an accelerator beam pipe. A primary motivation for the workshop was the expected harmful electron-cloud effects in the upgraded LHC injectors and in future linear colliders, as well as recent beam observations in operating facilities like ANKA, CESR, KEKB, RHIC, and SPS. The solutions discussed at ECL2 included enamel-based clearing electrodes, slotted vacuum chambers, NEG coating, and grooves. Several of the proposed cures were assessed in terms of their clearing efficiency and the associated beam impedance. The workshop also reviewed new simulation tools like the 3D electron-ion build-up 'Faktor', modeling assumptions, analytical calculations, beam experiments, and laboratory meas...

  6. Qualification of NPP operations personnel

    International Nuclear Information System (INIS)

    Wang Jiao.

    1987-01-01

    Competence of personnel is one of the important problems for safety operation of nuclear power plant. This paper gives a description of some aspects, such as the administration of NPP, posts, competence of personnel, training, assessing the competence and personnel management

  7. Long-term operation of a multi-channel cosmic muon system based on scintillation counters with MRS APD light readout

    CERN Document Server

    Akindinov, A.; Grigoriev, E.; Grishuk, Yu.; Kuleshov, S.; Mal'kevich, D.; Martemiyanov, A.; Nedosekin, A.; Ryabinin, M.; Voloshin, K.

    2009-01-01

    A Cosmic Ray Test Facility (CRTF) is the first large-scale implementation of a scintillation triggering system based on a new scintillation technique known as START. In START, the scintillation light is collected and transported by WLS optical fibers, while light detection is performed by pairs of avalanche photodiodes with the Metal-Resistor-Semiconductor structure operated in the Geiger mode (MRS APD). START delivers 100% efficiency of cosmic muon detection, while its intrinsic noise level is less than 10^{-2} Hz. CRTF, consisting of 160 START channels, has been continuously operated by the ALICE TOF collaboration for more than 25 000 hours, and has demonstrated a high level of stability. Fewer than 10% of MRS APDs had to be replaced during this period.

  8. Personnel policy and management

    International Nuclear Information System (INIS)

    Dangelmaier, P.

    1986-01-01

    In the field of personnel policy and management two main points must be considered and fitted together: the aspects of the applicant and the aspects of the utility. The applicant wishes a position which suits to his abilities, education, training, experience and self-evaluation. The enterprise has beside these qualification criteria to look to some additional points: reliability - not only in the profession of the applicant but also in his daily life. In this examination licensing authorities are involved too; responsibility in a very broad sense and the ability to make correct decisions sometimes under stress situations. (orig.)

  9. Characterization of high-sensitivity metal oxide semiconductor field effect transistor dosimeters system and LiF:Mg,Cu,P thermoluminescence dosimeters for use in diagnostic radiology

    International Nuclear Information System (INIS)

    Dong, S.L.; Chu, T.C.; Lan, G.Y.; Wu, T.H.; Lin, Y.C.; Lee, J.S.

    2002-01-01

    Monitoring radiation exposure during diagnostic radiographic procedures has recently become an area of interest. In recent years, the LiF:Mg,Cu,P thermoluminescence dosimeter (TLD-100H) and the highly sensitive metal oxide semiconductor field effect transistor (MOSFET) dosimeter were introduced as good candidates for entrance skin dose measurements in diagnostic radiology. In the present study, the TLD-100H and the MOSFET dosimeters were evaluated for sensitivity, linearity, energy, angular dependence, and post-exposure response. Our results indicate that the TLD-100H dosimeter has excellent linearity within diagnostic energy ranges and its sensitivity variations were under 3% at tube potentials from 40 Vp to 125 kVp. Good linearity was also observed with the MOSFET dosimeter, but in low-dose regions the values are less reliable and were found to be a function of the tube potentials. Both dosimeters also presented predictable angular dependence in this study. Our findings suggest that the TLD-100H dosimeter is more appropriate for low-dose diagnostic procedures such as chest and skull projections. The MOSFET dosimeter system is valuable for entrance skin dose measurement with lumbar spine projections and certain fluoroscopic procedures

  10. Assessing Doses to Interventional Radiologists Using a Personal Dosimeter Worn Over a Protective Apron

    International Nuclear Information System (INIS)

    Stranden, E.; Widmark, A.; Sekse, T.

    2008-01-01

    Background: Interventional radiologists receive significant radiation doses, and it is important to have simple methods for routine monitoring of their exposure. Purpose: To evaluate the usefulness of a dosimeter worn outside the protective apron for assessments of dose to interventional radiologists. Material and Methods: Assessments of effective dose versus dose to dosimeters worn outside the protective apron were achieved by phantom measurements. Doses outside and under the apron were assessed by phantom measurements and measurements on eight radiologists wearing two routine dosimeters for a 2-month period during ordinary working conditions. Finger doses for the same radiologists were recorded using thermoluminescent dosimeters (TLD; DXT-RAD Extremity dosimeters). Results: Typical values for the ratio between effective dose and dosimeter dose were found to be about 0.02 when the radiologist used a thyroid shield and about 0.03 without. The ratio between the dose to the dosimeter under and outside a protective apron was found to be less than 0.04. There was very good correlation between finger dose and dosimeter dose. Conclusion: A personal dosimeter worn outside a protective apron is a good screening device for dose to the eyes and fingers as well as for effective dose, even though the effective dose is grossly overestimated. Relatively high dose to the fingers and eyes remains undetected by a dosimeter worn under the apron

  11. Assessing Doses to Interventional Radiologists Using a Personal Dosimeter Worn Over a Protective Apron

    Energy Technology Data Exchange (ETDEWEB)

    Stranden, E.; Widmark, A.; Sekse, T. (Buskerud Univ. College, Drammen (Norway))

    2008-05-15

    Background: Interventional radiologists receive significant radiation doses, and it is important to have simple methods for routine monitoring of their exposure. Purpose: To evaluate the usefulness of a dosimeter worn outside the protective apron for assessments of dose to interventional radiologists. Material and Methods: Assessments of effective dose versus dose to dosimeters worn outside the protective apron were achieved by phantom measurements. Doses outside and under the apron were assessed by phantom measurements and measurements on eight radiologists wearing two routine dosimeters for a 2-month period during ordinary working conditions. Finger doses for the same radiologists were recorded using thermoluminescent dosimeters (TLD; DXT-RAD Extremity dosimeters). Results: Typical values for the ratio between effective dose and dosimeter dose were found to be about 0.02 when the radiologist used a thyroid shield and about 0.03 without. The ratio between the dose to the dosimeter under and outside a protective apron was found to be less than 0.04. There was very good correlation between finger dose and dosimeter dose. Conclusion: A personal dosimeter worn outside a protective apron is a good screening device for dose to the eyes and fingers as well as for effective dose, even though the effective dose is grossly overestimated. Relatively high dose to the fingers and eyes remains undetected by a dosimeter worn under the apron

  12. Performances of Dose Measurement of Commercial Electronic Dosimeters using Geiger Muller Tube and PIN Diode

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hyunjun; Kim, Chankyu; Kim, Yewon; Kim, Giyoon; Cho, Gyuseong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    There are two categories in personal dosimeters, one is passive type dosimeter such as TLD (thermoluminescence dosimeter) and the other is active type dosimeter such as electronic dosimeter can show radiation dose immediately while TLD needs long time to readout its data by heating process. For improving the reliability of measuring dose for any energy of radiations, electronic dosimeter uses energy filter by metal packaging its detector using aluminum or copper, but measured dose of electronic dosimeter with energy filter cannot be completely compensated in wide radiation energy region. So, in this paper, we confirmed the accuracy of dose measurement of two types of commercial EPDs using Geiger Muller tube and PIN diode with CsI(Tl) scintillator in three different energy of radiation field. The experiment results for Cs-137 was almost similar with calculation value in the results of both electronic dosimeters, but, the other experiment values with Na-22 and Co-60 had higher error comparing with Cs-137. These results were caused by optimization of their energy filters. The optimization was depending on its thickness of energy filter. So, the electronic dosimeters have to optimizing the energy filter for increasing the accuracy of dose measurement or the electronic dosimeter using PIN diode with CsI(Tl) scintillator uses the multi-channel discriminator for using its energy information.

  13. Training of personnel

    International Nuclear Information System (INIS)

    1997-01-01

    Selected staffs (in the area of NPPs) are examined by the State Examining Committee established by Nuclear Regulatory Authority of the Slovak Republic (NRA SR's) chairman. The committee consists of representatives of NRA SR , Bohunice NPPs, Mochovce NPP, Research Institute of Nuclear Energy and experts from the Faculty of Electrical Engineering and Information Technology of the Slovak Technical University. The review of selected personnel of NPP V-1, V-2 and Mochovce NPP which passed exams in 1996 is given. NRA SR paid attention to the upgrading training process of individual categories of staff for V-1, V-2 and Mochovce NPPs, simulator training and training with computerized simulation system according to the United criteria of nuclear installation personnel training that started in 1992. During the year, an inspection was performed focused on examination of technical equipment of the simulator of Mochovce NPP, professional eligibility and overall preparation of simulator training including simulator software. Throughout the year launching works continued at the simulator with the deadline of commissioning to trial use operation in the first half of 1997

  14. Personnel training and certification

    International Nuclear Information System (INIS)

    Whittemore, W.L.

    1976-01-01

    In order to make the full benefits of neutron radiography available in the nondestructive test (NDT) field, it has been necessary to formalize its application. A group under the Penetrating Radiation Committee of the American Society for Nondestructive Testing (ASNT) was organized to prepare a recommended practice for neutron radiography. The recommended practices require the establishment of an appropriate certification program. The requirements on the employer to establish and maintain a qualification and certification program are outlined. To conduct a program of nondestructive testing using neutron radiography requires the usual three levels of qualified and certified personnel. The program is administered by a Level III person. Routine exposure, reviews, and reporting of test results are the responsibilities of Level I and Level II personnal. The amount of training and nature of the required practical examination are also specified. The recommended practices document assures users that NDT work in the field of neutron radiography is performed by qualified personnel. Although no training courses are available to provide experience in the depth required by the recommended practices document, SNT-TC-1A, short courses are provided at a number of locations to familarize user's representatives with the interpretation of neutron radiographs and capabilities and limitations of the technique

  15. Reproducibility and signal response linearity of Alanine gel dosimeter

    International Nuclear Information System (INIS)

    Silva, Cleber Feijo Silva; Campos, Leticia Lucente

    2008-01-01

    Gel Dosimetry has been studied mainly for medical applications, because it presents signal response in the dose range used in radiotherapy treatments and it can be applied for three dimensional dosimetry. Alanine gel dosimeter is a new gel material developed at IPEN that presents significant improvement on previous alanine systems developed by Costa (1994). The DL-Alanine (C 3 H 7 NO 2 ) is an amino acid tissue equivalent that improves the production of ferric ions in the solution. These ferric ions concentration can be measured by spectrophotometry technique. This work aims to study the reproducibility of the alanine gel solutions and the signal response as a function of gamma radiation dose, considering that these two properties are very important for characterizing and standardizing any dosimeter. (author)

  16. Medical extrapolation chamber dosimeter model XW6012A

    International Nuclear Information System (INIS)

    Jin Tao; Wang Mi; Wu Jinzheng; Guo Qi

    1992-01-01

    An extrapolation chamber dosimeter has been developed for clinical dosimetry of electron beams and X-rays from medical linear accelerators. It consists of a new type extrapolation chamber, a water phantom and an intelligent portable instrument. With a thin entrance window and a φ20 mm collecting electrode made of polystyrene, the electrode spacing can be varied from 0.2 to 6 mm. The dosimeter can accomplish dose measurement automatically, and has functions of error self-diagnosis and dose self-recording. The energy range applicable is 0.5-20 MeV, and the dose-rate range 0.02-40 Gy/min. The total uncertainty is 2.7%

  17. Investigations of CR39 dosimeters for neutron routine dosimetry

    International Nuclear Information System (INIS)

    Weinstein, M.; Abraham, A.; Tshuva, A.; German, U.

    2004-01-01

    CR-39 is a polymeric nuclear track detector which is widely used for neutron dosimetry. CR-39 detector development was conducted at a number of laboratories throughout the world(1,2) , and was accepted also for routine dosimetry. However, there are shortcomings which must be taken into consideration the lack of a dosimetry grade material which causes batch variations, significant angular dependence and a moderate sensitivity. CR-39 also under-responds for certain classes of neutron spectra (lower energy neutrons from reactors or high energy accelerator-produced neutrons).In order to introduce CR-39 as a routine dosimeter at NRCN, a series of checks were performed. The present work describes the results of some of our checks, to characterize the main properties of CR-39 dosimeters

  18. Water-equivalence of gel dosimeters for radiology medical imaging

    International Nuclear Information System (INIS)

    Valente, M; Vedelago, J.; Perez, P.; Chacon, D.; Mattea, F.; Velasquez, J.

    2017-10-01

    International dosimetry protocols are based on determinations of absorbed dose to water. Ideally, the phantom material should be water equivalent; that is, it should have the same absorption and scatter properties as water. This study presents theoretical, experimental and Monte Carlo modeling of water-equivalence of Fricke and polymer (NIPAM, PAGAT and itaconic acid ITABIS) gel dosimeters. Mass and electronic densities along with effective atomic number were calculated by means of theoretical approaches. Samples were scanned by standard computed tomography and high-resolution micro computed tomography. Photon mass attenuation coefficients and electron stopping powers were examined by Monte Carlo simulations. Theoretical, Monte Carlo and experimental results confirmed good water-equivalence for all gel dosimeters. Overall variations with respect to water in the low energy radiology range (up to 130 k Vp) were found to be less than 3% in average. (Author)

  19. Electronic personal dosimeter heralds a revolution in legal dosimetry

    International Nuclear Information System (INIS)

    Fletcher, R.

    1991-01-01

    The Electronic Personal Dosimeter (EPD) developed by Siemens Plessey Controls and the UK's national Radiological Protection Board is approaching the pre-production stage. It provides ''legal'' dosimetry and all the features of a personal alarming dosimeter. The EPD uses solid state semiconductor detectors for gamma and beta radiation and has a dose threshold of about 1μ Sv, with a low energy gamma range down to 20 KeV. It has a multi function liquid crystal display for instant readout and audible and visual alarms. Two separates dose stores are maintained. Short term dose for tactical management and long term dose for approved dosimetry service record keeping. The latter can be reset only by an approved dosimetry service and is maintained on a search memory disk which can be read even if the EPD is destroyed. (UK)

  20. Some properties of commercial dyed plastic as radiation dosimeters

    International Nuclear Information System (INIS)

    Rageh, M.S.I.; El-Assy, N.B.; Ashry, M.

    1986-01-01

    The use of commercial dyed plastics (red and green perspex) as radiation dosimeters in a cobalt-60 sterilizing plant is described. The results are satisfactory and offer advantages over the other dosimeters. The increase in the optical density for red perspex at wavelengths 650 and 750 nm with radiation can be used for absorbed dose measurements over the ranges from 1 to 7.5 KGy and from 5 to 25 KGy correspondingly. The decrease in the optical density for green perspex at 596, 612 and 641 nm with absorbed dose can extend the linear response range up to about 45 KGy. The fading of intensity of the irradiation induced absorption bands in dyed plastics after storage at different temperatures had been investigated

  1. Water-equivalence of gel dosimeters for radiology medical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Valente, M; Vedelago, J.; Perez, P. [Instituto de Fisica Enrique Gaviola - CONICET, Av. Medina Allende s/n, Ciudad Universitaria, X5000HUA, Cordoba (Argentina); Chacon, D.; Mattea, F. [Universidad Nacional de Cordoba, FAMAF, Laboratorio de Investigacion e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Av. Medina Allende s/n, Ciudad Universitaria, X5000HUA Cordoba (Argentina); Velasquez, J., E-mail: valente@famaf.unc.edu.ar [ICOS Inmunomedica, Lago Puyehue 01745, Temuco (Chile)

    2017-10-15

    International dosimetry protocols are based on determinations of absorbed dose to water. Ideally, the phantom material should be water equivalent; that is, it should have the same absorption and scatter properties as water. This study presents theoretical, experimental and Monte Carlo modeling of water-equivalence of Fricke and polymer (NIPAM, PAGAT and itaconic acid ITABIS) gel dosimeters. Mass and electronic densities along with effective atomic number were calculated by means of theoretical approaches. Samples were scanned by standard computed tomography and high-resolution micro computed tomography. Photon mass attenuation coefficients and electron stopping powers were examined by Monte Carlo simulations. Theoretical, Monte Carlo and experimental results confirmed good water-equivalence for all gel dosimeters. Overall variations with respect to water in the low energy radiology range (up to 130 k Vp) were found to be less than 3% in average. (Author)

  2. The Response of Alanine Dosimeters in Thermal Neutron Fields

    DEFF Research Database (Denmark)

    Schmitz, T.; Bassler, Niels; Sharpe, P.

    response of all pellets could be reproduced by calculations within a uncertainty of 5 %. For all experiments three dose components have been separated. A proton dose is generated in the 14N(n,p)14C reaction. Secondary gammas are generated by various (n,γ) reactions, dominated by the 2.2 MeV photon from...... experiments the dosimeters will be exposed to higher neutron energies, which are more typical for BNCT treatments. References: [1] Barth, R.F; 2009: Boron neutron capture therapy at the crossroads: Challenges and opportunities. Applied Radiation and Isotopes 67, 3-6. [2] Rogus, R.D.; Harling, O.K.; Yanch, J.C...... for treatment of liver metastases. Applied Radiation and Isotopes 67, 238-241. [4] Sharpe, P.; Sephtan, J.; 2000: An automated system for the measurement of alanine/EPR dosimeters. Applied Radiation and Isotopes 52, 1185-1188....

  3. Laser CT evaluation on normoxic PAGAT gel dosimeter

    International Nuclear Information System (INIS)

    Kumar, D S; Samuel, E J J; Watanabe, Y

    2013-01-01

    Optical computed tomography has been shown to be a potentially useful imaging tool for the radiation therapy physicists. In radiation therapy, researchers have used optical CT for the readout of 3D dosimeters. The purpose of this paper is to describe the initial evaluation of a newly fabricated laser CT scanner for 3D gel dosimetry which works using the first generation principle. A normoxic PAGAT (Polyacrylamide Gelatin and Tetrakis) gel is used as a dosimeter for this analysis. When a laser passes through the gel phantom, absorption and scattering of photon take place. The optical attenuation coefficient of the laser can be obtained by measuring its intensity after passing through the gel by a sensor. The scanner motion is controlled by a computer program written in Microsoft Visual C++. Reconstruction and data analysis on the irradiated gel phantom is performed by suitable algorithm using Matlab software.

  4. Optical CT evaluation on normoxic polymer gel dosimeter

    International Nuclear Information System (INIS)

    Samuel, E. James Jebaseelan

    2013-01-01

    Optical computed tomography has been shown to be a potentially useful imaging tool for the radiation therapy physicists. In radiation therapy, researchers have used optical CT for the readout of 3D dosimeters. The purpose of this paper is to explicate the initial evaluation of a newly fabricated laser CT scanner for '3D gel dosimetry' which works in the first generation principle. The normoxic PAGAT (Polyacrylamide Gelatin and Tetrakis) gel is used as a dosimeter for this analysis. When laser passes through this gel phantom, absorption and scattering of photon take place. The optical attenuation coefficient of the laser can be obtained by measuring its intensity after passing through the gel by a sensor.The scanner motion is controlled by the program written in Microsoft Visual C++. Reconstruction and data analysis on the irradiated gel phantom is performed by suitable algorithm using Matlab software. (author)

  5. International intercomparison of environmental dosimeters under field and laboratory conditions

    International Nuclear Information System (INIS)

    Gesell, T.F.; de Planque Burke, G.; Becker, K.

    1975-04-01

    Based on the results of a pilot study at ORNL in 1973, a more comprehensive international intercomparison of integrating dosimeters for the assessment of external penetrating environmental radiation fields was carried out. Forty-one laboratories from eleven countries participated in this study. A total of 56 sets of six detectors each were mailed to and from Houston, Texas, where they were exposed for three months (July to September 1974) as follows: two in an unprotected space out-of-doors 1 m above ground; two in an air-conditioned shielded area with a known, low exposure rate; and two with the second group, but with an additional exposure to 30 mR. Evaluation of the dosimeters provides information on the calibration precision, the accuracy of field measurement, and transit exposure. Results are discussed. (U.S.)

  6. An improved design of QFE dosimeter charging unit

    International Nuclear Information System (INIS)

    Speight, R.G.; Clifton, J.J.

    1976-02-01

    The availability of commercial charging units for quartz fibre electroscope dosimeters (QFEs) in the United Kingdom has been limited to small battery units intended for use in laboratory conditions. The use of large numbers of QFEs by semi-skilled staff has resulted in damage to many dosimeters, particularly at the charging pins. Difficulties have also been experienced in the viewing of the scale and fibre in non-laboratory lighting conditions. These problems have resulted in the development of a robust charging and viewing unit, which is described in this report. The new unit which is mains electricity powered, is contained in a case 230 x 305 x 150 mm weighing 4.5 kg. (U.K.)

  7. Development of diffusion-based radon daughter dosimeters

    International Nuclear Information System (INIS)

    Phillips, C.R.; Khan, A.; Leung, H.

    1983-07-01

    The objective of this work is to investigate the possible application of the mechanisms of thermophoresis and electrostatic collection via electrets to the collection of radon daughters with reference to personal alpha dosimeters for use in uranium mines. The potential advantage accruing from adoption of either one of these collection mechanisms is that collection is passive and does not depend upon the use of a pump (active), and is, therefore, intrinsically much more reliable

  8. Letter concerning Li2B4O7 thermoluminescence dosimeters

    International Nuclear Information System (INIS)

    Soares, C.G.

    1979-01-01

    This letter reports the comparison of two commercially available types of lithium borate thermoluminesence dosimeters: one in which crystalline lithium borate was pressed into chips, and the other in which lithium borate was dispersed in a glass matrix. When irradiated with cobalt 60 gamma radiation, the response of a single sample of each type was reproducible to within 1%. However, differences between the two samples were apparent in their long term storage characteristics

  9. The radiation dosimeter on-board the FY-4 Satellite

    Science.gov (United States)

    Zhang, B.; Sun, Y.; Zhang, S.; Zhang, X.; Sun, Y.; Jing, T.

    2017-12-01

    The total radiation dose effect can lead to a decrease in the performance of satellite devices or materials. Accurately obtaining the total radiation dose during satellite operation could help to analyze the abnormality of payloads in orbit and optimize the design of radiation shielding. The radiation dosimeter is one of the space environmental monitoring devices on the "FY-4" satellite, which is a new generation of geostationary meteorological satellite. The dosimeter consists of 8 detectors, which are installed in different locations of the satellite, to obtain the total radiation dose with different shielding thickness and different orientations. To measure a total radiation dose up to 2000krad(Si), 100nm ion implantation RADFET was used. To improve the sensitivity of the dosimeter, the bias voltage of RADFET is set to 15V, and a 10V, 15-bit A/D is adopted to digitalize the RADFET's threshold voltage, which is increased as the total radiation dose grows. In addition, the temperature effect of RADFET is corrected from the measured temperature on orbit. The preliminary monitoring results show that the radiation dose is less than 35rad (Si) per day at 0.87 mm shielding thickness of equivalent aluminum in the geostationary orbit, and the dose in Y direction of the satellite is less than those in the X and Z directions. The radiation dose at the thickness of 3.87 mm equivalent aluminum is less than 1rad(Si)/day. It is found that the daily total dose measured by the dosimeter has a strong correlation with the flux of high energy electrons.

  10. Gaas Displacement Damage Dosimeter Based on Diode Dark Currents

    Directory of Open Access Journals (Sweden)

    Warner Jeffrey H.

    2017-01-01

    Full Text Available GaAs diode dark currents are correlated over a very large proton energy range as a function of displacement damage dose (DDD. The linearity of the dark current increase with DDD over a wide range of applied voltage bias deems this device an excellent candidate for a displacement damage dosimeter. Additional proton testing performed in situ enabled error estimate determination to within 10% for simulated space use.

  11. Calculated energy response of lithium fluoride finger-tip dosimeters

    International Nuclear Information System (INIS)

    Johns, T.F.

    1965-07-01

    Calculations have been made of the energy response of the lithium fluoride thermoluminescent dosimeters being used at A.E.E. Winfrith for the measurement of radiation doses to the finger-tips of people handling radio-active materials. It is shown that the energy response is likely to be materially affected if the sachet in which the powder is held contains elements with atomic numbers much higher than 9 (e.g. if the sachet is made from polyvinyl chloride). (author)

  12. Personnel Selection Method Based on Personnel-Job Matching

    OpenAIRE

    Li Wang; Xilin Hou; Lili Zhang

    2013-01-01

    The existing personnel selection decisions in practice are based on the evaluation of job seeker's human capital, and it may be difficult to make personnel-job matching and make each party satisfy. Therefore, this paper puts forward a new personnel selection method by consideration of bilateral matching. Starting from the employment thoughts of ¡°satisfy¡±, the satisfaction evaluation indicator system of each party are constructed. The multi-objective optimization model is given according to ...

  13. Design and Implementation of Accurate and Efficient Pocket Dosimeter

    International Nuclear Information System (INIS)

    Shehata, S.A.; Abdelkhalek, K.L.

    2005-01-01

    It is so important in the field of radiation therapy and radiation protection to have dosimeters to determine the absorbed dose, which is transferred to human body by ionizing radiation. In this paper the design and implementation of a wide-range pocket dosimeter (PKD-1) with high accuracy to measure personal equivalent dose and dose rate of gamma radiation will be presented. This pocket dosimeter is micro controller-based and powered from 9 V rechargeable battery. The overall power consumption is significantly reduced by smart software and hardware design allowing longer time intervals between recharging. The integrated alphanumerical LCD displays not only of the accumulated dose and current dose rate, but also displays alarm messages such as low battery. For reasons of power saving the LCD is activated on demand by pressing the push button or automatically when an alarm occurs. Audible and visual alarms have been added to PKD-1 in order that they cannot be accidentally overlooked or ignored. PKD-1 can be connected to any PC through its serial port (RS232) and User Interface software has been developed for easy displaying and recording of radiation readings over any time period

  14. Environmental radiation monitoring of nuclear sites by thermoluminescent dosimeters (TLD)

    International Nuclear Information System (INIS)

    Duftschmid, K.E.; Strachotinsky, Ch.

    1978-04-01

    The measurement of environmental radiation doses around nuclear facilities requires the detection of few mrem/year. The properties of the automatic TLD-system Harshaw Mod. 2271 for such measurements have been evaluated under practical conditions and optimized techniques derived. The automatic TLD-system is based on LiF dosimeter cards with two crystals providing gamma and beta dose values. Limit of detection defined as three standard deviations of residuel dose is 1,2 mR. Automatic readout combined with electronic data evaluation are especially useful for large monitoring networks. Practical intercomparisons of this dosimeter with bulb-type CaF 2 detectors have been performed showing good agreement of both detector. Although bulb-dosimeters proved to be extremely sensitive with a limit of detection at 0,012 mR which makes them very suitable for very short exposure times, the automatic LiF system is superior in regards of man power requirement if monthly monitoring periods are sufficient. The system has been tested in practice during two international intercomparisons performed by the US Department of Energy - Health and Safety Laboratory New York and the Physikalisch Technische Bundesanstalt Braunschweig, Germany, showing excellent agreement. Furthermore a routine monitoring network consisting of 12 measurement positions around the Research Center Seibersdorf has been operated with this technique since more than two years. (author)

  15. Calcium carbonate as a possible dosimeter for high irradiation doses

    International Nuclear Information System (INIS)

    Negron M, A.; Ramos B, S.; Camargo R, C.; Uribe, R. M.; Gomez V, V.; Kobayashi, K.

    2014-08-01

    The aim of this work is to analyze the interactions of 5 MeV electron beam radiation and a 290 MeV/u Carbon beam with calcium carbonate (powder) at 298 K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9 MGy, and with Carbon beam from 1.5 kGy to 8 kGy. High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR). An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. The response of one of the radicals decreased with the dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10 MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation. (author)

  16. Electron-energy deposition in skin and thermoluminescence dosimeters

    International Nuclear Information System (INIS)

    Mei, G.T.Y.

    1986-01-01

    The primary object of this study was to investigate the relations between dosimeter response and skin dose resulting from beta-particle irradiation. This object was achieved by combining evaluation of beta-source energy spectra, calculation of flux energy spectra, and employment of a Monte-Carlo electron-transport computer program for determination of depth-dose distribution in multislab geometries. Intermediate results from three steps of evaluation were compared individually with experimental data or with other theoretical results and showed excellent agreement. The combined method is applicable for the electron agreement. The combined method is applicable for the electron energy range of 1 keV to 5 MeV for both monoenergetic electrons and energy-distributed electrons. Determination of dosimeter response - skin dose relationships for homogeneous atmospheric beta-particle sources and for two specific configurations of LiF TLD's have been carried out in this study. Information based on these calculations is of value in designing beta-particle dosimeters as well as in assessing potential occupational and public health risks associated with the nuclear power industry

  17. Raman Spectroscopy of Irradiated Normoxic Polymethacrylic Acid Gel Dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Bong, Ji Hye; Kwon, Soo Il; Cho, Yu Ra; Park, Chae Hee; Park, Hyung Wook [Kyonggi University, Suwon (Korea, Republic of); Choi, Kyu Seok; Yu, Soo Chang [Kunsan National University, Gunsan (Korea, Republic of)

    2011-02-15

    A quantitative analysis of the decreasing rate of the monomer and increasing rate of the polymerization was made by monitoring radiation level increments using Raman spectroscopy within the therapeutic radiation range for a normoxic polymethacrylic acid gel dosimeter. The gel dosimeter was synthesized by stirring materials such as gelatin, distilled water, methacrylic acid, hydroquinone and tetrakis phosphonium chloride at 50 .deg. C, and the synthesized gel was contained in a 10- mm diameter and 32-mm high vial to conduct measurement. 24 hours after gel synthesis, it was irradiated from 0 Gy to 20 Gy by 2 Gy using a Co-60 radiotherapy unit. With use of the Cryo FE-SEM, structural changes in the 0 Gy and 10 Gy gel dosimeters were investigated. The Raman spectra were acquired using 532-nm laser as the excitation source. In accordance with fitting the changes in C-COOH stretching (801 cm{sup -1}), C=C stretching (1639 cm{sup -1}) and vinyl CH{sub 2} stretching (3114 cm{sup -1}) vibrational modes for monomer and CH{sub 2} bending vibrational mode (1451 cm{sup -1}) for polymer, sensitive parameter S for each mode was calculated. The values of S for monomer bands and polymer band were ranged in 6.0 ± 2.6 Gy and 7.2 ± 2.3 Gy, respectively, which shows a relatively good conformity of the decreasing rate of monomer and the increasing rate of polymerization within the range of error.

  18. Silver dichromate - a suitable dosimeter for radiation processing

    International Nuclear Information System (INIS)

    Hoang Hoa Mai; Nguyen Dinh Duong

    1995-01-01

    An aqueous dosimeter system based on solution of silver dichromate in perchloric acid and spectrophotometry analysis was investigated. The optical absorption characteristics of solutions have been studied. The molar extinction coefficients and radiation-yield of the dosimeter solutions were determined. The mechanism of radiation-induced reactions in the solutions is also considered. A formula for calculating the dose based on absorbance measurements is presented. The G-value of dichromate reduction caused by gamma radiation was determined. The value found, 0.397 is close to the values of the other authors. Two solutions with different concentrations of dichromate have been chosen to match two applicable dose ranges. The solution containing 0.5 mM Ag 2 Cr 2 O 7 in 0.1 M HClO 4 is applied to dose range of 1 -12 kGy and the solution with 0.5 mM Ag 2 Cr 2 O 7 and 2.00 mM K 2 Cr 2 O 7 in 0.1 M HClO 4 is applied to dose range of 3 to 50 kGy. It was found that the relationship between net absorbance ΔA and radiation dose, D is essentially linear over expected dose ranges. The calibration curves have been drawn up by using least square method. In routine use for gamma radiation the dosimeter show good accuracy, reproducibility and stability of the response. (author). 10 refs., 4 figs., 3 tabs

  19. An environmental BeO-OSL dosimeter for emergency response

    International Nuclear Information System (INIS)

    Woda, Clemens; Kaiser, Jan Christian; Urso, Laura; Greiter, Matthias

    2012-01-01

    A conceptual design is presented to use measurements of localized absorbed dose in inner cities for production of high resolution maps of the radioactive contamination following a nuclear emergency or radiological attack. The doses are derived from luminescent detectors pre-fixed at places of high importance (e.g. public squares). For such an environmental dosimeter, BeO is used, which can be read out using optically stimulated luminescence (OSL). A suitable casing of black Perspex has been developed to give a sufficiently accurate estimate of the air kerma value at the detector position. The dosimeter is characterized according to light tightness, dose response and angular photon energy dependence. A short overview of the approach for map production is also given. - Highlights: ► An inexpensive, environmentally stable BeO based OSL dosimeter has been developed for emergency response. ► The detector enables fast readouts and shows highly favorable dosimetric properties. ► A conceptual design is described to produce maps of radioactive contamination from localized dose measurements in urban areas.

  20. Calcium carbonate as a possible dosimeter for high irradiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Negron M, A.; Ramos B, S.; Camargo R, C. [UNAM, Instituto de Ciencias Nucleares, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Uribe, R. M. [Kent State University, College of Technology, Kent OH (United States); Gomez V, V. [UNAM, Instituto de Quimica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Kobayashi, K., E-mail: negron@nucleares.unam.mx [Yokohama National University (Japan)

    2014-08-15

    The aim of this work is to analyze the interactions of 5 MeV electron beam radiation and a 290 MeV/u Carbon beam with calcium carbonate (powder) at 298 K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9 MGy, and with Carbon beam from 1.5 kGy to 8 kGy. High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR). An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. The response of one of the radicals decreased with the dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10 MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation. (author)

  1. Fabrication and Optimization of a PAGATA Gel Dosimeter: Increasing the Melting Point of the PAGAT Gel Dosimeter with Agarose Additive

    Directory of Open Access Journals (Sweden)

    Bakhtiar Azadbakht

    2010-12-01

    Full Text Available Introduction: The PAGAT polymer gel dosimeter melts at 30 ˚C and even at room temperature during the summer, so it needs to be kept in a cool place such as a refrigerator. To increase the stability of the PAGAT gel, different amounts of agarose were added to the PAGAT gel composition and the PAGATA gel was manufactured. Material and Methods: The PAGATA gel vials were irradiated using a Co-60 machine. Then, the samples were evaluated using a 1.5 T Siemens MRI scanner. The ingredients of the PAGATA normoxic gel dosimeter were 4.5% N-N' methylen-bis-acrylamide, 4.5% acrylamide, 4.5% gelatine, 5 mM tetrakis (THPC, 0.01 mM hydroquinone (HQ, 0.5% agarose and 86% de-ionized water (HPLC. Results: Melting point and sensitivity of the PAGAT gel dosimeter with addition of 0.0, 0.3, 0.5, 1.0, 1.5 and 2.0% of agarose were measured, in which the melting points were increased to 30, 82, 86, 88, 89 and 90°C and their sensitivities found to be 0.113, 0.1059, 0.125, 0.122, 0.115 and 0.2  respectively. Discussion and Conclusions: Adding agarose increased the sensitivity and background R2 of the evaluated samples. The optimum amount of agarose was found to be 0.5% regarding these parameters and also the melting point of the gel dosimeter. A value of 0.5% agarose was found to be an optimum value considering the increase of sensitivity to 0.125 and melting point to 86°C but at the expense of increasing the background R2 to 4.530.

  2. Comparison between dosimeter films and electronic dosimeters results obtained in F-18 production practices at IEN/CNEN

    International Nuclear Information System (INIS)

    Paulo, Osvaldir; Carlos, Luiz R.J.; Mendes, Milton

    2008-01-01

    Full text: The aim of the present work is the comparison of the dose rates values obtained from dosimeter films with the values obtained from electronic dosimeters used by radiological protection technician involved in practices with fluorine-18 production in CV-28 cyclotron at IEN/CNEN. The motivation for this work was the increase on the demand of this radiopharmaceutical. Nowadays there is an increase demand on the number of clinics and hospitals which had started to use the technique of radiodiagnostic using positron-emission tomography (PET). Therefore, the produced radionuclide activities (physics quantity) and also the complexity of the practices of radiological protection in the areas of that facility had increased a lot. The conventional statistical methods will be used to evaluate the results obtained in the analysis of the data obtained in the reading of the dosimeters. This comparative method is however a first step to taking decisions regarding radiological protection service. Therefore that the radiometric surveys of routine are taken in consideration, as well as the information from the technician of radiological protection that is working in those areas. All this data will give support to improve and implement methods and practices on the accelerators' facilities. In addition, the use of these electronic dosimeters will makes possible the technician read these dose rates received immediately during the practices and use these information you make decisions. In case of dose rates values to present above the expected the practice will be ploughed. Another point to be considered is that this work will propitiate the future updates of the procedures designated to those practices and to conduct at the radiological protection optimization. (author)

  3. Investigation of radiological properties and water equivalency of PRESAGE dosimeters

    International Nuclear Information System (INIS)

    Gorjiara, Tina; Hill, Robin; Kuncic, Zdenka; Adamovics, John; Bosi, Stephen; Kim, Jung-Ha; Baldock, Clive

    2011-01-01

    Purpose: PRESAGE is a dosimeter made of polyurethane, which is suitable for 3D dosimetry in modern radiation treatment techniques. Since an ideal dosimeter is radiologically water equivalent, the authors investigated water equivalency and the radiological properties of three different PRESAGE formulations that differ primarily in their elemental compositions. Two of the formulations are new and have lower halogen content than the original formulation. Methods: The radiological water equivalence was assessed by comparing the densities, interaction probabilities, and radiation dosimetry properties of the three different PRESAGE formulations to the corresponding values for water. The relative depth doses were calculated using Monte Carlo methods for 50, 100, 200, and 350 kVp and 6 MV x-ray beams. Results: The mass densities of the three PRESAGE formulations varied from 5.3% higher than that of water to as much as 10% higher than that of water for the original formulation. The probability of photoelectric absorption in the three different PRESAGE formulations varied from 2.2 times greater than that of water for the new formulations to 3.5 times greater than that of water for the original formulation. The mass attenuation coefficient for the three formulations is 12%-50% higher than the value for water. These differences occur over an energy range (10-100 keV) in which the photoelectric effect is the dominant interaction. The collision mass stopping powers of the relatively lower halogen-containing PRESAGE formulations also exhibit marginally better water equivalency than the original higher halogen-containing PRESAGE formulation. Furthermore, the depth dose curves for the lower halogen-containing PRESAGE formulations are slightly closer to that of water for a 6 MV beam. In the kilovoltage energy range, the depth dose curves for the lower halogen-containing PRESAGE formulations are in better agreement with water than the original PRESAGE formulation. Conclusions: Based

  4. Development of a miniaturized watch-type dosimeter using a silicon printed-circuit board

    International Nuclear Information System (INIS)

    Ishikura, Takeshi; Sakamaki, Tsuyoshi; Matsumoto, Iwao; Aoyama, Kei; Nakamura, Takashi

    2008-01-01

    The electrical personal dosimeter using a silicon semiconductor sensor has the advantage of real time response and alarm function, which can prevent unexpected over-exposure. We tried to develop a miniaturized watch-type dosimeter by incorporating the silicon semiconductor sensor on a silicon printed-circuit board. Thin film resistors, capacitors and wiring patterns are formed on a downsized printed-circuit board. Electronic parts including transistors are mounted by soldering on the silicon printed-circuit board. The dosimeter is further miniaturized by downsizing the amplifier circuit, the semiconductor radiation sensor, the power supply circuit, setting parts and alarm part. The performance of the developed dosimeter was evaluated with respect to the gamma-ray spectra, angular dependence and linearity to dose equivalent rate, and it was confirmed that this dosimeter has the performance equivalent to a commercially available electrical personal dosimeter. (author)

  5. EPR of gamma-irradiated polycrystalline alanine-in-glass dosimeter

    International Nuclear Information System (INIS)

    Al-Karmi, Anan M.; Morsy, M.A.

    2008-01-01

    This study attempts to overcome some of the reported discrepancies in alanine-EPR reproducibility that may be related to alanine dosimeter preparation and/or EPR spectrometer settings. The dosimeters were prepared by packing pure polycrystalline L-α-alanine directly as supplied by the manufacturer in glass tubes. This dosimeter production scheme avoids any possible contribution to the EPR signal from a binding material. The dosimeters were irradiated with gamma ray to low-dose ranges typical for medical therapy (0-20 Gy). Special attention has been paid to the study of minimum detectable dose, measurement repeatability and reproducibility, and post-irradiation stability. The dosimeter exhibited a linear dose response in the dose range from 0.1 to 20 Gy. These positive properties favor the polycrystalline alanine-in-glass tube as a radiation dosimeter

  6. Studies on reduction of dosimeter used in the product dose mapping process at Sinagama Plant

    International Nuclear Information System (INIS)

    Sofian Ibrahim; Syuhada Ramli; Cosmos George; Zarina Mohd Nor; Kamarudin Buyong; Shahidan Yob; Nor Ishadi Ismail; Mohd Sidek Othman; Ahsanulkhaliqin Abdul Wahab; Mohd Khairul Azfar Ramli

    2012-01-01

    Product dose mapping is the determination of the best product loading configuration which will be used during routine sterilization. In product dose mapping, dosimeters are placed throughout products at strategic locations to determine the zones of minimum and maximum dose. On previous Sinagama's product dose mapping method, a total of 240 unit's ceric-cerous dosimeter been used for a tote. Based on the data obtained from Irradiator Dose Mapping Report in 2004 and data from recent studies, the number of dosimeter to be used in product dose mapping can be reduced to 28 units without sacrificing precision and accuracy of the dose mapping results. This also led changes of the placing dosimeter method from Plane system to Coordinate system. Reduction of 88 % on dosimeters usage will directly reduce the cost of expenses on dosimeter, time and labor. (author)

  7. Dose response of thin-film dosimeters irradiated with 80-120 keV electrons

    DEFF Research Database (Denmark)

    Helt-Hansen, J.; Miller, A.; Sharpe, P.

    2005-01-01

    Thin-film dosimeters (Riso B3 and alanine films) were irradiated at 10 MeV and 80-120 keV electron accelerators, and it has been shown that the radiation response of the dosimeter materials (the radiation chemical yields) are constant at these irradiation energies. However, dose gradients within ...... are present within the dosimeter. (C) 2005 Elsevier Ltd. All rights reserved....

  8. Automatic dosimeter for kerma measurement based on commercial PIN photo diodes

    International Nuclear Information System (INIS)

    Kushpil, V.; Kushpil, S.; Huna, Z.

    2011-01-01

    A new automatic dosimeter for measurement of radiation dose from neutron and ionization radiation is presented. The dosimeter (kerma meter) uses commercial PIN diodes with long base as its active element. Later it provides a maximal dependence of the minority carriers life time versus absorbed dose. The characteristics of the dosimeter were measured for several types of commercial diodes. Device can be useful in many environmental or industrial applications. (authors)

  9. Design of Interrogation Protocols for Radiation Dose Measurements Using Optically-Stimulated Luminescent Dosimeters.

    Science.gov (United States)

    Abraham, Sara A; Kearfott, Kimberlee J; Jawad, Ali H; Boria, Andrew J; Buth, Tobias J; Dawson, Alexander S; Eng, Sheldon C; Frank, Samuel J; Green, Crystal A; Jacobs, Mitchell L; Liu, Kevin; Miklos, Joseph A; Nguyen, Hien; Rafique, Muhammad; Rucinski, Blake D; Smith, Travis; Tan, Yanliang

    2017-03-01

    Optically-stimulated luminescent dosimeters are capable of being interrogated multiple times post-irradiation. Each interrogation removes a fraction of the signal stored within the optically-stimulated luminescent dosimeter. This signal loss must be corrected to avoid systematic errors in estimating the average signal of a series of optically-stimulated luminescent dosimeter interrogations and requires a minimum number of consecutive readings to determine an average signal that is within a desired accuracy of the true signal with a desired statistical confidence. This paper establishes a technical basis for determining the required number of readings for a particular application of these dosimeters when using certain OSL dosimetry systems.

  10. Dose intercomparison study involving Fricke, ethanol chlorobenzene, PMMA and alanine dosimeters

    International Nuclear Information System (INIS)

    Lanuza, L.G.; Cabalfin, E.G.; Kojima, T.; Tachibana, H.

    1999-01-01

    A dose intercomparison study was carried out between the Philippine Nuclear Research Institute (PNRI) and Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute (JAERI) to determine reliability of the dosimetry systems being used by PNRI employing ethanol chlorobenzene (ECB), Fricke and alanine dosimeters. The Fricke and ECB dosimeters were prepared at PNRI while the alanine-polystyrene dosimeter was provided by JAERI. Fricke or ECB dosimeters were irradiated together with alanine at PNRI gamma irradiation facilities. Analyses of the Fricke and ECB dosimeters were performed at PNRI while alanine dosimeters were analyzed at JAERI. A comparison study between alanine and polymethylmethacrylate (PMMA, Radix RN15) dosimeters was also undertaken at JAERI. The dosimeters were irradiated together under different irradiation conditions using the gamma irradiation facilities of JAERI and Radia Industry Co. Ltd. (Japan). Evaluations of PMMA and alanine dosimeters were both performed at JAERI. Result of the dose intercomparison of PNRI with the International Atomic Energy Agency through the International Dose Assurance Service (IDAS) is also presented. (author)

  11. Dose intercomparison study involving Fricke, ethanol chlorobenzene, PMMA and alanine dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Lanuza, L G; Cabalfin, E G [Philippine Nuclear Research Institute, Quezon City (Philippines); Kojima, T; Tachibana, H [Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research institute, Takasaki (Japan)

    1999-03-01

    A dose intercomparison study was carried out between the Philippine Nuclear Research Institute (PNRI) and Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute (JAERI) to determine reliability of the dosimetry systems being used by PNRI employing ethanol chlorobenzene (ECB), Fricke and alanine dosimeters. The Fricke and ECB dosimeters were prepared at PNRI while the alanine-polystyrene dosimeter was provided by JAERI. Fricke or ECB dosimeters were irradiated together with alanine at PNRI gamma irradiation facilities. Analyses of the Fricke and ECB dosimeters were performed at PNRI while alanine dosimeters were analyzed at JAERI. A comparison study between alanine and polymethylmethacrylate (PMMA, Radix RN15) dosimeters was also undertaken at JAERI. The dosimeters were irradiated together under different irradiation conditions using the gamma irradiation facilities of JAERI and Radia Industry Co. Ltd. (Japan). Evaluations of PMMA and alanine dosimeters were both performed at JAERI. Result of the dose intercomparison of PNRI with the International Atomic Energy Agency through the International Dose Assurance Service (IDAS) is also presented. (author) 8 refs, 3 figs, 4 tabs

  12. Site security personnel training manual

    International Nuclear Information System (INIS)

    1978-10-01

    As required by 10 CFR Part 73, this training manual provides guidance to assist licensees in the development of security personnel training and qualifications programs. The information contained in the manual typifies the level and scope of training for personnel assigned to perform security related tasks and job duties associated with the protection of nuclear fuel cycle facilities and nuclear power reactors

  13. Personnel Officers: Judging Their Qualifications.

    Science.gov (United States)

    Webb, Gisela

    1988-01-01

    Discusses the backgrounds and qualifications appropriate for a library personnel administrator, including (1) a master's degree in library science; (2) library work experience; (3) additional training in administration, personnel management, organizational development, and psychology; and (4) personal attributes such as good communication skills,…

  14. Personnel Practices for Small Colleges.

    Science.gov (United States)

    Bouchard, Ronald A.

    Personnel administration in higher education is the focus of this "hands-on, how-to-do-it" guide that provides fundamental materials for developing and maintaining a sound personnel program. Part One (Employment) examines government regulations, employee recruitment and selection, pre-employment inquiries and screening, post-employment process,…

  15. Special training of shift personnel

    International Nuclear Information System (INIS)

    Martin, H.D.

    1981-01-01

    The first step of on-the-job training is practical observation phase in an operating Nuclear Plant, where the participants are assigned to shift work. The simulator training for operating personnel, for key personnel and, to some extent, also for maintenance personnel and specialists give the practical feeling for Nuclear Power Plant behaviour during normal and abnormal conditions. During the commissioning phase of the own Nuclear Power Plant, which is the most important practical training, the participants are integrated into the commissioning staff and assisted during their process of practical learning by special instructors. The preparation for the licensing exams is vitally important for shift personnel and special courses are provided after the first non-nuclear trial operation of the plant. Personnel training also includes performance of programmes and material for retraining, training of instructors and assistance in building up special training programmes and material as well as training centers. (orig./RW)

  16. Optimizing the sensitivity and radiological properties of the PRESAGE® dosimeter using metal compounds

    International Nuclear Information System (INIS)

    Alqathami, Mamdooh; Blencowe, Anton; Qiao, Greg; Adamovics, John; Geso, Moshi

    2012-01-01

    The aim of this study is to investigate the radiation-modifying effects of incorporating commercially available bismuth-, tin- and zinc-based compounds in the composition of the PRESAGE ® dosimeter, and the feasibility of employing such compounds for radiation dose enhancement. Furthermore, we demonstrate that metal compounds can be included in the formulation to yield water-equivalent PRESAGE ® dosimeters with enhanced dose response. Various concentrations of the metal compounds were added to a newly developed PRESAGE ® formulation and the resulting dosimeters were irradiated with 100 kV and 6 MV photon beams. A comparison between sensitivity and radiological properties of the PRESAGE ® dosimeters with and without the addition of metal compounds was carried out. Optical density changes of the dosimeters before and after irradiation were measured using a spectrophotometer. In general, when metal compounds were incorporated in the composition of the PRESAGE ® dosimeter, the sensitivity of the dosimeters to radiation dose increased depending on the type and concentration of the metal compound, with the bismuth compound showing the highest dose enhancement factor. In addition, these metal compounds were also shown to improve the retention of the post-response absorption value of the PRESAGE ® dosimeter over a period of 2 weeks. Thus, incorporating 1–3 mM (ca. 0.2 wt%) of any of the three investigated metal compounds in the composition of the PRESAGE ® dosimeter is found to be an efficient way to enhance the sensitivity of the dosimeter to radiation dose and stabilize its post-response for longer times. Furthermore, the addition of small amounts of the metal compounds also accelerates the polymerization of the PRESAGE ® dosimeter precursors, significantly reducing the fabrication time. Finally, a novel water-equivalent PRESAGE ® dosimeter formula optimized with metal compounds is proposed for clinical use in both kilovoltage and megavoltage radiotherapy

  17. Modelling the behaviour of the push-pull gel dosimeter

    International Nuclear Information System (INIS)

    Bosi, S.G.; Davies, J.B.; Gorjiara, T.; Baldock, C.

    2010-01-01

    Full text: Recent development of a gel dosimeter based on the radiobleaching pigment, genipin, allows development of a new 3D optically scanned gel dosimeter-the p ush-pull g el. This gel would contain two spectrally complementary pigments, one which darkens with dose and another (e.g. genipin) which bleaches. The two pigments deal separately with the high and low dose ends of the dosimeter's dynamic range. The bleaching pigment would be optimised for high sensitivity and the darkening pigment for low. Employing dual pigments, optimised independently, relaxes the need for compromise between sensitivity at low dose and accuracy at high dose. Such a gel, after exposure, would be read using two successive optical CT scans, at two different wavelengths. The reduction in sensitivity of the darkening pigment (allowed by the use of push-pull) would reduce the occurrence of regions of high optical attenuation which can generate optical CT artefacts. Simulated optical CT reconstructions of the optical density map (Fig. La) scanned at the darkening pigment wavelength of a hypothetical push-pull gel, confirms the reduction in susceptibility to artefacts. Fig. I b shows a profile through the map with no stray light added. The centre of the profile in Fig. I d shows a cupping artefact produced by 10 ppm of stray light. The similarity of Fig. Ic and b show that a 30% sensitivity reduction allowed by push-pull, renders the artefact negligible. This paper presents the results of' these simulations of a push-pull gel scanned using optical CT and also some results of experiments with genipin gel. (author)

  18. Development of new chemical dosimeter for low dose range

    International Nuclear Information System (INIS)

    Mhatre, Sachin G.V.; Adhikari, S.

    2012-01-01

    Accurate measurement of low dose radiation in complex systems is of utmost importance in radiation biology and related areas. Ferrous Benzoic acid Xylenol orange (FBX) system is being widely used for measurement of low dose gamma radiation because of its reproducibility and precision. However, an additional step, i.e., dissolution of benzoic acid in water at higher temperature followed by cooling at room temperature is involved for the preparation of this dosimeter. This makes it inconvenient as a ready to use dosimeter. In the present work, the organic molecule, sorbitol has been used for measurement of low doses of radiation. The advantages of using sorbitol are its ready availability and instantaneous water solubility. Owing to its dissolution at room temperature, possible errors those are involved in calculation of dose due to thermal oxidation of ferrous ions during preparation of the FBX dosimetric solution could be made insignificant in the proposed dosimeter. In the present system, sorbitol acts as radiolytic sensitizer for the oxidation of ferrous ion, and xylenol orange forms a 1:1 complex specifically with ferric ions. Thus, the analytical detection limit of ferric ions is enhanced compared to other systems. Final composition of the dosimetric solution is; 0.5 mol/m 3 xylenol orange, 10 mol/m 3 sorbitol and 0.2 mol/m 3 ferrous ion in 50 mol/m 3 sulfuric acid. Radiolytic sensitization in combination with analytical enhancement of the ferrous based system, allows us to measure radiation dose in the range of 0.05 Gy–12 Gy with ease and high reproducibility.

  19. Desk-top computer assisted processing of thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    Archer, B.R.; Glaze, S.A.; North, L.B.; Bushong, S.C.

    1977-01-01

    An accurate dosimetric system utilizing a desk-top computer and high sensitivity ribbon type TLDs has been developed. The system incorporates an exposure history file and procedures designed for constant spatial orientation of each dosimeter. Processing of information is performed by two computer programs. The first calculates relative response factors to insure that the corrected response of each TLD is identical following a given dose of radiation. The second program computes a calibration factor and uses it and the relative response factor to determine the actual dose registered by each TLD. (U.K.)

  20. Preliminary study of diffusion effects in Fricke gel dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Quiroga, A. [Centro de Investigacion y Estudios de Matematica de Cordoba, Oficina 318 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina); Vedelago, J. [Laboratorio de Investigaciones e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Laboratorio 448 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina); Valente, M., E-mail: aiquiroga@famaf.unc.edu [Instituto de Fisica Enrique Gaviola, Oficina 102 FaMAF - UNC, Av. Luis Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2014-08-15

    Diffusion of ferric ions in ferrous sulfate (Fricke) gels represents one of the main drawbacks of some radiation detectors, like Fricke gel dosimeters. In practice, this disadvantage can be overcome by prompt dosimeter analysis, constraining strongly the time between irradiation and analysis. Due to required integral accuracy levels, special dedicated protocols are implemented with the aim of minimizing signal blurring due to diffusion effects. This work presents dedicated analytic modelling and numerical calculations of diffusion coefficients in Fricke gel radiation sensitive material. Samples are optically analysed by means of visible light transmission measurements capturing images with a Ccd camera provided with a monochromatic 585 nm filter corresponding to the X O-infused Fricke solution absorbance peak. Dose distributions in Fricke gels are suitably delivered in order to assess specific initial conditions further studied by periodical sample image acquisitions. In a first analytic approach, experimental data are fit with linear models in order to achieve a value for the diffusion coefficient. The second approach to the problem consists on a group of computational algorithms based on inverse problem formulation, along with suitable 2D diffusion model capable of estimating diffusion coefficients by fitting the obtained algorithm numerical solutions with the corresponding experimental data. Comparisons are performed by introducing an appropriate functional in order to analyse both experimental and numerical values. Solutions to second order diffusion equation are calculated in the framework of a dedicated method that incorporates Finite Element Method. Moreover, optimised solutions can be attained by gradient type minimisation algorithms. Knowledge about diffusion coefficient for Fricke gel radiation detector might be helpful in accounting for effects regarding elapsed time between dosimeter irradiation and further analysis. Hence, corrections might be included

  1. Oscillometric and conductometric analysis of aqueous and organic dosimeter solutions

    DEFF Research Database (Denmark)

    Kovacs, A.; Slezsak, I.; McLaughlin, W.L.

    1995-01-01

    Conductometric and oscillometric evaluation methods have earlier been developed to determine absorbed dose in the ethanol-monochlorobenzene dosimeter solution. Recent investigations on the same solution as well as on alanine solutions included the study of the possible use of different type ''con...... of the applicable concentration of the alanine solute and the dose (1 to 50 kGy) and dose-rate range using both electron (2.6 mu s at 13 mu A to 4 mu s at 1.0 A pulse length and beam current) and gamma radiation (0.13 to 30 kGy h(-1))....

  2. Preliminary study of diffusion effects in Fricke gel dosimeters

    International Nuclear Information System (INIS)

    Quiroga, A.; Vedelago, J.; Valente, M.

    2014-08-01

    Diffusion of ferric ions in ferrous sulfate (Fricke) gels represents one of the main drawbacks of some radiation detectors, like Fricke gel dosimeters. In practice, this disadvantage can be overcome by prompt dosimeter analysis, constraining strongly the time between irradiation and analysis. Due to required integral accuracy levels, special dedicated protocols are implemented with the aim of minimizing signal blurring due to diffusion effects. This work presents dedicated analytic modelling and numerical calculations of diffusion coefficients in Fricke gel radiation sensitive material. Samples are optically analysed by means of visible light transmission measurements capturing images with a Ccd camera provided with a monochromatic 585 nm filter corresponding to the X O-infused Fricke solution absorbance peak. Dose distributions in Fricke gels are suitably delivered in order to assess specific initial conditions further studied by periodical sample image acquisitions. In a first analytic approach, experimental data are fit with linear models in order to achieve a value for the diffusion coefficient. The second approach to the problem consists on a group of computational algorithms based on inverse problem formulation, along with suitable 2D diffusion model capable of estimating diffusion coefficients by fitting the obtained algorithm numerical solutions with the corresponding experimental data. Comparisons are performed by introducing an appropriate functional in order to analyse both experimental and numerical values. Solutions to second order diffusion equation are calculated in the framework of a dedicated method that incorporates Finite Element Method. Moreover, optimised solutions can be attained by gradient type minimisation algorithms. Knowledge about diffusion coefficient for Fricke gel radiation detector might be helpful in accounting for effects regarding elapsed time between dosimeter irradiation and further analysis. Hence, corrections might be included

  3. Developing a biological dosimeter based on mitochondrial DNA

    Energy Technology Data Exchange (ETDEWEB)

    Adams, S; Carlisle, S M; Unrau, P; Deugau, K V [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

    1996-12-31

    Direct measurement of deoxyribonucleic acid (DNA) damage from ionizing radiation may be advantageous in determining radiation radiation exposures and assessing their effects on atomic radiation workers. The mitochondrial DNA molecule is one potential cellular DNA target which is: fully defined and sequenced; present in many copies per cell; not vital to cellular survival; and less subject to DNA repair than nuclear DNA. A method is described to isolate and analyse normal mitochondrial DNA. We describe the developments needed to determine DNA damage in mitochondrial DNA. The target is to make a biological dosimeter. (author). 6 refs., 3 figs.

  4. Detector and dosimeter for neutrons and other radiation

    International Nuclear Information System (INIS)

    Apfel, R.E.

    1979-01-01

    A radiation detector and dosimeter is based on the fact that a sufficiently finely-dispersed liquid suspended in a host liquid of high viscosity or gel is stable at temperatures above its normal boiling point for long periods of time provided it is protected from contact with walls, or other types of initiators which can cause volatilization or vaporization of the droplets. Radiation, and particularly neutron radiation of sufficient energy and intensity on coming in contact with such droplets can trigger volatilization. The volume of vapor evolved can then serve as a measure of radiation intensity and dosage

  5. Low-cost commercial glass beads as dosimeters in radiotherapy

    International Nuclear Information System (INIS)

    Jafari, S.M.; Bradley, D.A.; Gouldstone, C.A.; Sharpe, P.H.G.; Alalawi, A.; Jordan, T.J.; Clark, C.H.; Nisbet, A.; Spyrou, N.M.

    2014-01-01

    Recent developments in advanced radiotherapy techniques using small field photon beams, require small detectors to determine the delivered dose in steep dose gradient fields. Commercially available glass jewellery beads exhibit thermoluminescent properties and have the potential to be used as dosimeters in radiotherapy due to their small size ( 60 Co gamma rays over doses ranging from 1 to 2500 cGy. A thermoluminescence (TL) system and an electron paramagnetic resonance (EPR) system were employed for read out. Both the TL and EPR studies demonstrated a radiation-induced signal, the sensitivity of which varied with bead colour. White coloured beads proved to be the most sensitive for both systems. The smallest and therefore least sensitive bead sizes allowed measurement of doses of 1 cGy using the TL system while that for the EPR system was approximately 1000 cGy. The fading rate was found to be 10% 30 days after irradiation with both readout systems. The dose response is linear with measured dose over the dose range 1 to 2500 cGy, with an R 2 correlation coefficient of greater than 0.999. The batch-to-batch reproducibility of a set of dosimeters after a single irradiation was found to be 3% (1 SD). The reproducibility of individual dosimeters was found to be 1.7%. No measurable angular dependence was found (results agreed within 1%). Dose rate response was found to agree within 1% for dose rates of 100 to 600 cGy/min. These results demonstrate the potential use of glass beads as TL dosimeters over the dose range commonly applied in radiotherapy. - Highlights: • We examined the dosimetric properties of a low cost commercially produced glass seed beads. • Glass beads are available in small size of 1–3 mm, suitable for dosimetry of small radiation fields. • The results demonstrate a mean reproducibility of 0.23% (2 SD), batch homogeneity of within 5%. • Dose response was linear over wide dose range tested for 1 cGy to kGy. • Improved fading effect of 10

  6. Determination of surface dose rate for cloisonne using thermoluminescent dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Hengyuan, Zhao; Yulian, Zhang

    1985-07-01

    In this paper, the measuring method and results of surface dose rate of cloisonne using CaSO/sub 4/ Dy-Teflon foil dosimeter are described. The surface dose rate of all products are below 0.015 mrad/h. These products contain 42 sorts of jewelery and 20 sets of wares (such as vases, plates, ash-trays, etc.). Most of the data fall within the range of natural background. For comparison, some jewelery from Taiwan and 3 vases from Japan are measured. The highest surface dose rate of 0.78 mrad/h is due to the necklace jewelery from Taiwan.

  7. Developing a biological dosimeter based on mitochondrial DNA

    International Nuclear Information System (INIS)

    Adams, S.; Carlisle, S.M.; Unrau, P.; Deugau, K.V.

    1995-01-01

    Direct measurement of deoxyribonucleic acid (DNA) damage from ionizing radiation may be advantageous in determining radiation radiation exposures and assessing their effects on atomic radiation workers. The mitochondrial DNA molecule is one potential cellular DNA target which is: fully defined and sequenced; present in many copies per cell; not vital to cellular survival; and less subject to DNA repair than nuclear DNA. A method is described to isolate and analyse normal mitochondrial DNA. We describe the developments needed to determine DNA damage in mitochondrial DNA. The target is to make a biological dosimeter. (author). 6 refs., 3 figs

  8. Quality assurance manual for the Department of Energy laboratory accreditation program for personnel dosimetry systems

    International Nuclear Information System (INIS)

    1987-02-01

    The overall purpose of this document is to establish a uniform approach to quality assurance. This will ensure that uniform, high-quality personnel dosimetry practices are followed by the participating testing laboratories. The document presents guidelines for calibrating and maintaining measurement and test equipment (M and TE), calibrating radiation fields, and subsequently irradiating and handling personnel dosimeters in laboratories involved in the DOE dosimetry systems testing program. Radiation energies for which the test procedures apply are photons with approximately 15 keV to 2 MeV, beta particles above 0.3 MeV, neutrons with approximately 1 keV to 2 MeV. 12 refs., 4 tabs

  9. Radiation exposure to patients and personnel during percutaneous renal calculus extraction

    International Nuclear Information System (INIS)

    Khandelwal, K.C.; Kooka, D.M.; Dagaonkar, S.S.; Supe, S.J.

    1990-01-01

    Radiation exposure to the patient, radiologist and other personnel was measured during 20 percutaneous renal calculus extractions. Thermoluminescent dosimeters were used. The average skin dose for patient at the level of the testis was 80 mrem, and at the level of the kidney, 17.2 rem. Radiation exposure to the personnel was measured at the levels of forehead, thyroid, chest and testis. The average dose to these regions ranged between 0.20 mrem and 2.5 mrem. The radiologist's hand received on average radiation of 88.8 mrems. The patient skin surface exposure at the nephrostomy site are comparable to skin doses from standard procedures. The exposure to the radiologist is similar to that from other interventional fluoroscopic procedures and is within acceptable limits. (author). 10 refs., 3 tabs

  10. Development of optically stimulated luminescence technology for personnel monitoring applications at Bhabha Atomic Research Centre

    International Nuclear Information System (INIS)

    Kulkarni, M.S.

    2012-01-01

    The popularity of optically stimulated luminescence (OSL) technology in the radiation dosimetry applications, in general, and personnel and environmental monitoring, in particular, has driven investigation and developmental programme using OSL technique for a viable system for personnel monitoring at Bhabha Atomic Research Centre. The OSL related phosphor materials and instrumentation development has a very recent history in Bhabha Atomic Research Centre. The OSL technique is more versatile and easy to use than thermoluminescence (TL) technique. The X- and gamma ray (both high and low energy) photons and beta particles can be measured with OSL technique. In the OSL technique, the phosphor (say á- Ai 2 O 3 :C) is optically stimulated by blue/green light and the resulting light emitted from Al 2 O 3 :C (410-420 nm) is measured and correlated to the amount of radiation exposure. For a fixed stimulation intensity, the emitted blue light from the Al 2 O 3 :C dosimeter is proportional to the radiation exposure. The OSL technology is being increasingly used in several applications in external radiation dosimetry, in-vivo medical dosimetry in radiotherapy, in-situ, long-term monitoring system for radioactive contaminants, geological and archaeological dating of sediments, etc. For the success of OSL technology for large scale countrywide personnel monitoring program, indigenous development of dosimetric grade sensitive detector material was a key issue. Therefore, since 2002, efforts were directed towards the development of OSL phosphors (like aluminum oxide doped with carbon, á- Al 2 O 3 :C) and related instrumentation. To begin with, simple low cost OSL readers were developed using blue (470 nm) and green (530 nm) LED clusters. New techniques were developed for the preparation of dosimetric grade á- Ai 2 O 3 :C and other OSL phosphors. With the success in the development of indigenous technique for the large scale preparation of á- Al 2 O 3 :C phosphor, a four

  11. Development of based on 89S51 single-chip microcomputer electronic dosimeter

    International Nuclear Information System (INIS)

    Wang Junhua; Zhou Jiachao; Sun Jianghan; Du Xiao

    2009-01-01

    It describes the main design features and basic properties of based on 89S51 single-chip microcomputer electronic dosimeter with wide range and multi purposes. The dosimeter can display dose rate or accumulative dose or the maximum dose rate, record accumulative dose, the maximum dose rate and classes. (authors)

  12. Calibration of an ALBEDO termoluminiscent dosimeter for its use in personal dosimetry

    International Nuclear Information System (INIS)

    Diaz Bernal, E.; Molina Perez, D.; Cornejo Diaz, N.; Carrazana Gonzalez, J.

    1996-01-01

    The dosimetric studies began after the Radiological Individuals Surveillance Department from the Radiation Protection and Hygiene Center acquired the albedo thermoluminescent dosimeters model JR1104. This paper reviews the response of those dosimeters to the different spectrums and incidence angles of neutronic radiation

  13. Evaluation of performance of metal oxide-silicon semiconductor field effect transistor (MOSFET) dosimeter

    International Nuclear Information System (INIS)

    Nagashima, Hiroyuki; Sano, Naoki; Nakamura, Osamu

    2001-01-01

    The JARP level dosimeter is the most suitable for absorbed dose determination in radiotherapy because of its high accuracy. However, in measuring the dose of an extremely small field, a dosimeter with a smaller active region is required. The active region of the MOSFET dosimeter is very small, having a volume of just 0.02 mm 3 . In this study, we evaluated the performance of MOSFET dosimeters with two different sensitivities and examined the usefulness of the MOSFET dosimeter in stereotactic radiosurgery. Using the high-sensitivity MOSFET dosimeter, we were able to reduce the experimental error of absorbed dose (≤±1.8%), and, by correcting the sensitivity, we could use it as a field dosimeter. By turning detectors inside out, we could reduce directional dependence (≤±1.8%). Correction was necessary in the TMR determination because peak depth shifts according to the material of the detector. In the determination of the dose distribution in the penumbra, the resolution of the MOSFET detectors was equal to that of the diamond detector. In the determination of OPF for the extremely small field, better results were obtained with MOSFET than with other small detectors. The high-sensitivity MOSFET dosimeter could properly evaluate the dose of an extremely small field and will be useful in dosimetry of the maximum dose of the field center in stereotactic radiosurgery. (author)

  14. Evidence for and implications of self-background of radon dosimeters with glass-fiber filters

    NARCIS (Netherlands)

    Put, L.W.; Lembrechts, J.; van der Graaf, E.R.; Stoop, P.

    The first national radon survey in the Netherlands was conducted in 1984 with passive radon dosimeters that contain glass-fiber diffusion filters. During the last few years, measurements of outdoor-radon concentrations and information in the literature suggested to us that these dosimeters may give

  15. Estimation of personal dose based on the dependent calibration of personal dosimeters in interventional radiology

    International Nuclear Information System (INIS)

    Mori, Hiroshige; Koshida, Kichiro; Ichikawa, Katsuhiro

    2007-01-01

    The purpose of present study is, in interventional radiology (IVR), to elucidate the differences between each personal dosimeter, and the dependences and calibrations of area or personal dose by measurement with electronic dosimeters in particular. We compare space dose rate distributions measured by an ionization survey meter with the value measured by personal dosimeter: an optically stimulated luminescence, two fluoroglass, and two electronic dosimeters. Furthermore, with electronic dosimeters, we first measured dose rate, energy, and directional dependences. Secondly, we calibrated the dose rate measured by electronic dosimeters with the results, and estimated these methods with coefficient of determination and Akaike's Information Criterion (AIC). The results, especially in electronic dosimeters, revealed that the dose rate measured fell by energy and directional dependences. In terms of methods of calibration, the method is sufficient for energy dependence, but not for directional dependence, because of the lack of stable calibration. This improvement poses a question for the future. The study suggested that these dependences of the personal dosimeter must be considered when area or personal dose is estimated in IVR. (author)

  16. Reliability of an x-ray system for calibrating and testing personal radiation dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Guimarães, M.C.; Silva, C.R.E.; Silva, T.A. da [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Rosado, P.H.G.; Cunha, P.G. [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Metrology laboratories are expected to maintain standardized radiation beams and traceable standard dosimeters to provide reliable calibrations or testing of detectors. Results of the characterization of an x-ray system for performing calibration and testing of radiation dosimeters used for individual monitoring are shown in this work. (author)

  17. Reliability of an x-ray system for calibrating and testing personal radiation dosimeters

    Science.gov (United States)

    Guimarães, M. C.; Silva, C. R. E.; Rosado, P. H. G.; Cunha, P. G.; Da Silva, T. A.

    2018-03-01

    Metrology laboratories are expected to maintain standardized radiation beams and traceable standard dosimeters to provide reliable calibrations or testing of detectors. Results of the characterization of an x-ray system for performing calibration and testing of radiation dosimeters used for individual monitoring are shown in this work.

  18. Reliability of an x-ray system for calibrating and testing personal radiation dosimeters

    International Nuclear Information System (INIS)

    Guimarães, M.C.; Silva, C.R.E.; Silva, T.A. da; Rosado, P.H.G.; Cunha, P.G.

    2017-01-01

    Metrology laboratories are expected to maintain standardized radiation beams and traceable standard dosimeters to provide reliable calibrations or testing of detectors. Results of the characterization of an x-ray system for performing calibration and testing of radiation dosimeters used for individual monitoring are shown in this work. (author)

  19. Water equivalence of NIPAM based polymer gel dosimeters with enhanced sensitivity for x-ray CT

    Science.gov (United States)

    Gorjiara, Tina; Hill, Robin; Bosi, Stephen; Kuncic, Zdenka; Baldock, Clive

    2013-10-01

    Two new formulations of N-isopropylacrylamide (NIPAM) based three dimensional (3D) gel dosimeters have recently been developed with improved sensitivity to x-ray CT readout, one without any co-solvent and the other one with isopropanol co-solvent. The water equivalence of the NIPAM gel dosimeters was investigated using different methods to calculate their radiological properties including: density, electron density, number of electrons per grams, effective atomic number, photon interaction probabilities, mass attenuation and energy absorption coefficients, electron collisional, radiative and total mass stopping powers and electron mass scattering power. Monte Carlo modelling was also used to compare the dose response of these gel dosimeters with water for kilovoltage and megavoltage x-ray beams and for megavoltage electron beams. We found that the density and electron density of the co-solvent free gel dosimeter are more water equivalent with less than a 2.6% difference compared to a 5.7% difference for the isopropanol gel dosimeter. Both the co-solvent free and isopropanol solvent gel dosimeters have lower effective atomic numbers than water, differing by 2.2% and 6.5%, respectively. As a result, their photoelectric absorption interaction probabilities are up to 6% and 19% different from water, respectively. Compton scattering and pair production interaction probabilities of NIPAM gel with isopropanol differ by up to 10% from water while for the co-solvent free gel, the differences are 3%. Mass attenuation and energy absorption coefficients of the co-solvent free gel dosimeter and the isopropanol gel dosimeter are up to 7% and 19% lower than water, respectively. Collisional and total mass stopping powers of both gel dosimeters differ by less than 2% from those of water. The dose response of the co-solvent free gel dosimeter is water equivalent (with x-ray beams over the energy range 180 keV-18 MV, both gel dosimeters have less than 2% discrepancy with water. For

  20. A modified Fricke gel dosimeter for fast electron blood dosimetry

    International Nuclear Information System (INIS)

    Del Lama, L.S.; Góes, E.G. de; Sampaio, F.G.A.; Petchevist, P.C.D.; Almeida, A. de

    2014-01-01

    It has been suggested for more than forty years that blood and blood components be irradiated before allogeneic transfusions for immunosuppressed patients in order to avoid the Transfusion-Associated Graft-versus-Host Disease (TA-GVHD). Whole blood, red blood cells, platelets and granulocytes may have viable T cells and should be irradiated before transfusion for different patient clinical conditions. According to international guides, absorbed doses from 25 up to 50 Gy should be delivered to the central middle plane of each blood bag. Although gamma and X-rays from radiotherapy equipments and dedicated cell irradiators are commonly used for this purpose, electron beams from Linear Accelerators (LINACs) could be used as well. In this work, we developed a methodology able to acquire dosimetric data from blood irradiations, especially after fast electrons exposures. This was achieved using a proposed Fricke Xylenol Gel (FXG p ) dosimeter, which presents closer radiological characteristics (attenuation coefficients and stopping-powers) to the whole blood, as well as complete absorbed dose range linearity. The developed methodology and the FXG p dosimeter were also able to provide isodose curves and field profiles for the irradiated samples