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Assessment of Occupational Radiation Exposure for Radiotherapy Healthcare Workers at Kenyatta National Hospital Using Thermoluminescence Dosimeter LiF:Mg,Ti
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作者 Collins Omondi Margaret Chege Samson Omondi 《Journal of Geoscience and Environment Protection》 2024年第7期14-24,共11页
Kenyatta National Hospital (KNH) is the largest public referral hospital with a comprehensive cancer treatment facility in East and Central Africa. Occupational radiation monitoring is a significant technique for demo... Kenyatta National Hospital (KNH) is the largest public referral hospital with a comprehensive cancer treatment facility in East and Central Africa. Occupational radiation monitoring is a significant technique for demonstrating compliance of radiation regulatory limits. The objective of the study was to carry out assessment of occupational radiation exposure among radiotherapy personnel at KNH using thermoluminescence dosimeter, TLD. KNH staff were monitored using dosimeter type TLD-100 made of LiF:Mg,Ti, on monthly basis. The reader system used for analysis was Harshaw 8800. The measurement established the average monthly accumulated occupational personnel dose for KNH to be 0.21 mSv and 0.29 mSv for Hp (10) and Hp (0.07) respectively. The accumulated dose results were within the maximum acceptable dose of 1.67 mSv/month and 41.6 mSv/month for Hp (10) and Hp (0.07) respectively. The investigation results were higher than the acceptable public limit of 0.08 mSv/month. Moreover, incidences were noted where the fetus dose limit 0.42 was also exceeded. Evaluation of statistical dose exposure among doctors, nurses and radiographers’ measurement results were within ±0.02 mSv. The study established the average KNH occupational radiation exposure levels for both Hp (10) and Hp (0.07) were within the ICRU recommendation, validating radiation protection safe practice. Data analysis of healthcare workers did not indicate exposure trend biased to any healthcare profession. Hence radiation risk cut across all professional categories. It is recommended that Radiation Monitoring program be reviewed to include non-clinical staff who access the facility. Radiation reporting should not be limited to one facility, but reflect cases where workers are involved in multiple multiple jobs. 展开更多
关键词 Occupational Monitoring EXPOSURE Thermoluminescence dosimeter and Radiotherapy
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Performance of a plastic scintillation fiber dosimeter based on different photoelectric devices 被引量:3
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作者 Yue Yang Cui-Ping Yang +6 位作者 Jie Xin Hai-Feng Chen Zhong-Xu Xing Wei-Wei Qu Liang Hu Xin-Jian Chen Ren-Sheng Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2021年第11期25-31,共7页
The photoelectric device of a scintillation dosimeter converts photons produced by radiation into an electrical signal.Its features directly determine the overall performance of the dosimeter.For a plastic scintillati... The photoelectric device of a scintillation dosimeter converts photons produced by radiation into an electrical signal.Its features directly determine the overall performance of the dosimeter.For a plastic scintillation fiber dosimeter(PSFD)with a current readout mode,systematic studies of the stability and light-dose response were performed for the photomultiplier tube(PMT),silicon photomultiplier(SiPM),avalanche photodiode(APD),and photodiode(PD).The temperature stability,long-term stability,repeatability,signal-to-noise ratio(SNR),and current dose response of the PSFD with the abovementioned photoelectric devices were studied using a pulsed LED light source and the Small Animal Radiation Therapy platform.An exponential relationship between the dark/ne current and temperature was obtained for all the devices.I is shown that the APD is the most sensitive device to temperature,with a current dependence on temperature reaching 6.5%C^(-1)at room temperature,whereas for the other devices this dependence is always<0:6%C^(-1).In terms of long-term stability,the net current of PD can change by up to 4%when working continuously for 8 h and 2%when working intermittently for 32 h,whereas for the other devices,the changes are all<1%.For the dose response,the PMT and SiPM exhibit excellent linear responses and SNRs within the range of 0.1-60 Gy/min For the PSFD with a current readout mode,the performance of the PMT and SiPM is concluded to be better than that of the other devices in the study.In particular,the SiPM,which has a compact size,low bias voltage,and antimagnetic interference,has great advantages for further applications. 展开更多
关键词 Photoelectric device Plastic scintillation fiber dosimeter(PSFD) Current readout Dose response
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The study on optically stimulated luminescence dosimeter based on the SrS:Eu,Sm and CaS:Eu,Sm 被引量:3
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作者 刘艳平 陈朝阳 +5 位作者 范艳伟 巴维真 郭旗 陆妩 汤新强 杜彦召 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第8期3156-3162,共7页
With the increasing use of nuclear energy, there is a need for a wider range of efficient dosimeters for radiation detection and assessment. There has been a tremendous growth in the development of radiation detectors... With the increasing use of nuclear energy, there is a need for a wider range of efficient dosimeters for radiation detection and assessment. There has been a tremendous growth in the development of radiation detectors and devices in the past few decades. In recent years, the development of new materials for radiation dosimetry has progressed significantly. Alkaline earth sulfides (AES) have been known for a long time as excellent and versatile phosphor materials. In the present investigation, a number of phosphor samples such as mono-, binary and ternary sulfides of alkaline earths (II^a-VI^b) have been prepared and their TL properties have been studied with respect to exposure (x-ray) response and fading. In this paper, some results on SrS:Eu, Sm and CaS:Eu, Sm phosphors are presented. A type of novel OSL dosimeter is described. The dosimeter takes advantage of the characteristics of charge trapping materials SrS:Eu, Sm and CaS:Eu, Sm that exhibit optically stimulated luminescence (OSL). The measuring range of the dosimeter is from 0.01 to 1000 Gy. The OSL dosimeters provide capability for remote monitoring radiation locations which are difficult to access and hazardous. This equipment is relatively simple, small in size and has low power consumption. The device is suitable for space radiation dose exploration. In addition, it also can be used in IC and other radiation occasions and has good prospects. 展开更多
关键词 optically stimulated luminescence RADIATION dosimeter
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KCl:Eu^(2+) as a solar UV-C radiation dosimeter. Optically stimulated luminescence and thermoluminescence analyses 被引量:1
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作者 I.Aguirre de Cárcer H.L.D'Antoni +2 位作者 M.Barboza-Flores V.Correcher F.Jaque 《Journal of Rare Earths》 SCIE EI CAS CSCD 2009年第4期579-583,共5页
The KCI:Eu2+ system response to UV-C was investigated by analyzing the optically stimulated luminescence (OSL) and ther- mo-luminescence (TL) signal produced by ultraviolet light exposure at room temperature. It... The KCI:Eu2+ system response to UV-C was investigated by analyzing the optically stimulated luminescence (OSL) and ther- mo-luminescence (TL) signal produced by ultraviolet light exposure at room temperature. It was found that after UV-C irra.diation, OSL was produced on a wide band of visible wavelengths with decay time that varied by several orders of magnitude depending on the Eu2+ aggregation state. In spite of the low intensity of solar UV-C reaching the Earth's surface in Madrid (40° N, 700 m a.s.1.), it was possible to measure the UV-C radiation dose at 6:48 solar time by using the TL response of the KCI:Eu2+ system and differentiate it from the ambient beta radiation dose. 展开更多
关键词 THERMO-LUMINESCENCE rare-earth-doped alkali halides solar ultraviolet dosimeter environmental radiation
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WDVE—6/100医用电子直线加速器DOSIMETER报警故障一例
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作者 张秀文 李文立 王功明 《医疗装备》 1999年第11期45-45,共1页
关键词 WDVE-6/100型 医用电子直线加速器 dosimeter 故障检修 机械计数器
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RESEARCH ON FADING CHARACTERISTICS OF ALANINE/ESR DOSIMETERS IN HIGH DOSE RANGE
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作者 陈丽姝 H.Tachibana Y.Haruyama 《Nuclear Science and Techniques》 SCIE CAS CSCD 1993年第1期4-10,共7页
The present work has dealt extensively and systematically with the fading characteristics of polystyrene-alanine dosimeters irradiated at different dose rates and total doses under various temperatures (10-70 ℃) and ... The present work has dealt extensively and systematically with the fading characteristics of polystyrene-alanine dosimeters irradiated at different dose rates and total doses under various temperatures (10-70 ℃) and stored a period of time in different conditions (5, 25, room temperature, 40 ℃). Detail investigation on this effect in practical irradiation condition is very important. Because it is difficult to correct this effect using correction coefficients so far. So the temperature coefficients and fading rates have been given along with a lot of experimental data to try to make approximation of radical formation or decay behavior. 展开更多
关键词 Radiation processing dosimetry PS-alanine dosimeter ESR Transfer dosimeter Temperature coefficients FADING behaviour
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GENERAL PROPERTIES OF DOMESTIC RADIOCHROMIC FILM ELECTRON DOSIMETER
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作者 陈丽姝 闻友勤 孙存普 《Nuclear Science and Techniques》 SCIE CAS CSCD 1991年第4期193-198,共6页
The project established a system for routine measurement of electron dose and brought about a complete experimental approach for high-dose dosimetry. The paper reports some general properties of domestic radiochromic ... The project established a system for routine measurement of electron dose and brought about a complete experimental approach for high-dose dosimetry. The paper reports some general properties of domestic radiochromic pararosaniline cyanide (PR-CN) dye with polyvinyl butyral (PVB)-based film used for measuring electron dose. The optical absorption spectrum, the change in optical density as a function of thickness, distribution of the background optical density and spread of response, long-term stability, linear relationship between the change in optical density per unit thickness and absorbed dose, the minimum detectable limit, effect of environmental factors on background and response after irradiation, effect of light-exposition and the time of establishing complete response have been experimentally investigated. 展开更多
关键词 ELECTRON dosimeter High DOSE DOSIMETRY Film dosimeter RADIATION processing
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Water equivalence of some 3D dosimeters:a theoretical study based on the effective atomic number and effective fast neutron removal cross section
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作者 A.M.El-Khayatt 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第12期170-181,共12页
Effective atomic numbers for photon energy absorption(ZPEA_(eff)) and their corresponding electron numbers (NPEA_(eff)), and effective macroscopic removal cross sections of fast neutrons(RR) were calculated for 27 dif... Effective atomic numbers for photon energy absorption(ZPEA_(eff)) and their corresponding electron numbers (NPEA_(eff)), and effective macroscopic removal cross sections of fast neutrons(RR) were calculated for 27 different types of three-dimensional dosimeters, four types of phantom materials, and water. The values of ZPEA_(eff) and NPEA_(eff) were obtained using the direct method for energies ranging from 10 keV to 20 MeV. Results are presented relative to water, for direct comparison over the range of examined energies. The effect of monomers that are used in polymer gel dosimeters on the water equivalence is discussed. The relation between Σ_R and hydrogen content was studied. Micelle gel dosimeters are highly promising because our results demonstrate perfect matching between the effective atomic number, electron density number, and fast neutron attenuation coefficient of water. 展开更多
关键词 3D dosimeterS WATER EQUIVALENCE EFFECTIVE atomic number Photon energy absorption REMOVAL cross section Fast neutrons
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Simulation of gamma minitype reference radiation for calibration of personal dosimeter
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作者 Yi-Xin Liu Yi-Kun Qian +3 位作者 Zhi-Qiang Chen Biao Wei Peng Feng Ben-Jiang Mao 《Nuclear Science and Techniques》 SCIE CAS CSCD 2020年第1期112-122,共11页
An investigation using Monte Carlo simulation on a minitype reference radiation(MRR) for the calibration of gamma personal dosimeters is reported. The distributions of dose rate and scattering gamma spectrum are the m... An investigation using Monte Carlo simulation on a minitype reference radiation(MRR) for the calibration of gamma personal dosimeters is reported. The distributions of dose rate and scattering gamma spectrum are the main simulation objects with the variable physical structures of MRR and the dosimeters as parameters that are to be calibrated. Further, the influences on the reference radiation caused by these parameters are analyzed in detail.This work provides a theoretical basis for better understanding of MRR used for calibration of gamma personal dosimeters. This analysis can help in the development of a calibration technology for such tools based on MRR. 展开更多
关键词 Gamma personal dosimeter Minitype reference radiation Monte Carlo simulation CALIBRATION
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The Effect of the Size of Radiotherapy Photon Beams on the Absorbed Dose to an Al_2O_3 Dosimeter
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作者 陈少文 张文澜 +2 位作者 范丽仙 唐强 刘小伟 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第6期558-562,共5页
The effect of the size of radiotherapy photon beams on the absorbed dose to an Al2O3 dosimeter was investigated using the Monte Carlo method. The EGSnrc/DOSRZnrc program code was used to simulate the absorbed dose to ... The effect of the size of radiotherapy photon beams on the absorbed dose to an Al2O3 dosimeter was investigated using the Monte Carlo method. The EGSnrc/DOSRZnrc program code was used to simulate the absorbed dose to the Al2O3 dosimeter, as well as the absorbed dose to water at the corresponding position in the absence of the dosimeter. The incident beams were 60Co γ and 6 MV with a different beam radius ranging from 0.1 cm to 2 cm. Results revealed that the absorbed dose ratio factor depends on the size of the incident photon beam. When the radius of the incident beam is smaller than that of the dosimeter, the absorbed dose ratio factor decreases as the incident beam size increases. The absorbed dose ratio factor reaches its minimum when the radius of the incident beam is almost the same as that of the dosimeter. When the radius of the incident beam is larger than that of the dosimeter, the absorbed dose ratio factor increases as the incident beam size increases. The maximum difference among these absorbed dose ratio factors can be up to 14% in 60Co γ beams and 23% in 6 MV beams. However, when the size of the incident beam is much larger than that of the dosimeter, the effect of the incident beam size on the absorbed dose ratio factor becomes quite small. The maximum discrepancy between the absorbed dose ratio factors and the average value is not more than 1%. 展开更多
关键词 Al2O3 dosimeter absorbed dose Monte Carlo radiotherapy photon beams
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Intercomparison of Environmental Gamma doses Measured with A NaI(Tl) Survey Meter and Thermoluminescent Dosimeters(TLDs) in the Poonch Division of Azad Kashmir, Pakistan
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作者 Muhammad Rafique Kimberlee J Kearfott +6 位作者 Khalil Ahmad Jabeen Akhter Abdul Razzaq Khan Raja Azhar Saeed Saeed Ur Rahman Matiullah Muhammad Usman Rajput 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2014年第12期969-972,共4页
This study presents the intercomparison of the outdoor environmental gamma dose rates measured using a Nal (TI) based survey meter along with thermoluminescent dosimeters (TLDs) and estimation of excess lifetime c... This study presents the intercomparison of the outdoor environmental gamma dose rates measured using a Nal (TI) based survey meter along with thermoluminescent dosimeters (TLDs) and estimation of excess lifetime cancer risk (ELCR), for the inhabitants of Poonch division of the Azad Kashmir, Pakistan. CaF2: Dy (TLD-200) card dosimeters were installed at height of 1 m from ground at fifteen different locations covering the entire Poonch division comprising of three districts. 展开更多
关键词 in the Poonch Division of Azad Kashmir Survey Meter and Thermoluminescent dosimeters TL TLDs NAI
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Comparison of Gamma Pass Rate between the Dose-to-Water and Dose-to-Medium Reporting Modes for Patient-Specific QA Using a Helical Diode Array Dosimeter with a Fixed Phantom Density
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作者 Hideaki Hirashima Mitsuhiro Nakamura +7 位作者 Yoshitomo Ishihara Nobutaka Mukumoto Mami Akimoto Tsuneyuki Tomita Yoshinori Hirose Kenji Kitsuda Takashi Ishigaki Takashi Mizowaki 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2018年第1期74-86,共13页
Introduction: To compare the measured dose distributions to calculated ones in dose-to-water (Dw) and dose-to-medium (Dm) reporting modes for simple plans and patient-specific intensity modulated radiation therapy (IM... Introduction: To compare the measured dose distributions to calculated ones in dose-to-water (Dw) and dose-to-medium (Dm) reporting modes for simple plans and patient-specific intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans using ArcCHECK with a fixed phantom density. Methods: The recommended density value of 1.18 g/cm3 for Acuros XB and X-ray voxel Monte Carlo was assigned to ArcCHECK on CT images. A total of 45 simple plans, including a 1-field plan, a 3-field plan, a 4-field plan, a half-arc plan from 270° to 90°, and a full-arc plan, were assessed. Subsequently, the patient-specific 96 IMRT and VMAT plans were evaluated. Gamma analysis with a 3% normalized global dose error and a 3 mm distance-to-agreement criteria (γ3%G/3mm) was performed in the Dw and Dm. The change in γ3%G/3mm between Dw and Dm were statistically analyzed using JMPPro11 software. Results: The median values of γ3%G/3mm for all simple plans for Dw and Dm were 98.1% (range, 75.2% - 100%) and 95.5% (range, 23.7% - 100%), respectively (p 0.01). In the patient-specific IMRT and VMAT plans, the median values of γ3%G/3mm for Dw and Dm were 98.6% (range, 90.1% - 100%) and 90.5% (range, 38.5% - 97.2%), respectively (p 0.01). Conclusion: Our results showed that the calculated and measured dose distributions were in good agreement for Dw, but were not for Dm. From the viewpoint of the rationale of dosimetry, Dw shows better agreement with measured dose distribution when using the fixedphantom density recommended by the vendor. 展开更多
关键词 HELICAL Diode Array dosimeter Dose-to-Water Dose-to-Medium GAMMA Pass Rate
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NONLINEAR RESPONSES OF GAMMA-RAY DOSIMETERS
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作者 罗达玲 杨健明 张纯祥 《Nuclear Science and Techniques》 SCIE CAS CSCD 1994年第1期58-64,共7页
Either sublinear or supralinear responses of dosimeters to y-ray can be described by a response function derived from statistical Poisson distribution.The characteristic parameters of the function determine linearity,... Either sublinear or supralinear responses of dosimeters to y-ray can be described by a response function derived from statistical Poisson distribution.The characteristic parameters of the function determine linearity, sublinearity and supralinearity in their responses. The experimental data of gamma dose-responses of alanine ESR dosimeters,film dosimeters, LiF(Mg, Cu, P) and LiF(Mg, Ti) thermoluminescence dosimeters are used to test the response function. 展开更多
关键词 dosimeterS Nonlinear responses y-ray
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Disposable Condenser Dosimeter Using a Skin-Insulated Mini-Substrate with a Silicon X-Ray Diode in Image-Guided Radiation Therapy
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作者 Satoshi Yamaguchi Eiichi Sato +5 位作者 Ryuji Nakamura Hirobumi Oikawa Hisao Kakuhara Koyo Kikuchi Hisanori Ariga Shigeru Ehara 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2018年第1期35-46,共12页
To measure integral doses in image-guided radiation therapy, we developed a disposable mini-substrate with a 1.0-μF condenser and a silicon X-ray diode (Si-XD). The Si-XD is a high-sensitivity photodiode selected for... To measure integral doses in image-guided radiation therapy, we developed a disposable mini-substrate with a 1.0-μF condenser and a silicon X-ray diode (Si-XD). The Si-XD is a high-sensitivity photodiode selected for detecting X-rays. In the substrate with dimensions of 15 × 15 mm2, the initial charging voltage is 3.30 V, and the charging voltage is decreased by photocurrents flowing through the Si-XD during X-ray exposing. The condenser in the substrate is charged by a microcomputer dock, and the charging voltage is also measured using an analog to digital converter in the dock after exposing X-rays. The dock is connected to a personal computer through a USB cable, and integral doses are shown on the PC monitor. The doses were proportional to decreases in the charging voltage, and the calibrated doses corresponded well to those obtained using a readily available ionization chamber. 展开更多
关键词 CONDENSER dosimeter DISPOSABLE Mini-Substrate Surface
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Studying of Common Factors Affecting Reading of Lithium Fluoride Thermo-Luminescence Dosimeter Crystal
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作者 Mohammed A. Ali Omer Abdulrahman A. Alsayyari +3 位作者 Jumaa Y. Tamboul Rowida B. Ali Amira A. Ahmed Ahmed Abukonna 《Open Journal of Biophysics》 2017年第1期14-24,共11页
The aim of this study was to study the technical factors affecting the reading of TLD (LiF:Mg:Ti) for radiation dosimetry. The method adapted was an exposure of LiF:Mg:Ti crystal with?γ-ray with the following filters... The aim of this study was to study the technical factors affecting the reading of TLD (LiF:Mg:Ti) for radiation dosimetry. The method adapted was an exposure of LiF:Mg:Ti crystal with?γ-ray with the following filters (Hp 0.07 and Hp?10), before and after usage of filter Hp?(0.07), annealing, cooling by nitrogen flux and crystal morphology by scanning electron microscope. The collected data analyzed by EXCELL software showed that: TLD average count/second (C/s) with filter Hp?(10) was greater than that obtained with filter Hp?(0.07) with an amount of 1191 c/s?(19%). Also the analysis showed that: the average C/s without filter Hp?(0.07) was greater than that with filter by an amount of 994.5 C/s (16.4%), and there was proportional linear relationship;as the applied dose increased the TLD C/s increased significantly (R2?=?0.9) based on the equations: y = 885.1x???286.5 and y = 860.5x?+ 856.8 for filtered and without filtered beam respectively, where?x?refers to applied dose in mGy and?y?refers to C/s. Also the average C/s without nitrogen flux (cooling) was greater than with nitrogen count with an amount of 52.4 C/s (11%). The annealing (without filter) causes a reduction in dose by 82.2?μGy (19.2%), and in case of annealing with filter, the dose reduced by 66.7?μGy (21.9%) relative to annealing without filter. The morphology of TLD crystal shown by scanning electron microscope SEM was a darkening surface after irradiation. 展开更多
关键词 Radiation Effects dosimeter Factors THERMOLUMINESCENCE
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Toluidine Blue O-Gelatin Gel Dosimeter for Radiation Processing
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作者 S. M. Gafar M. A. El-Kelany +1 位作者 M. A. El-Ahdal S. R. El-Shawadfy 《Open Journal of Polymer Chemistry》 2014年第3期56-61,共6页
In this study the spectrophotometric response of the Toluidine Blue O (TBO)-gelatin gel dosimeter irradiated with gamma rays was characterized. Preparation of dyed-gelatin gel takes place in neutral medium;to give eve... In this study the spectrophotometric response of the Toluidine Blue O (TBO)-gelatin gel dosimeter irradiated with gamma rays was characterized. Preparation of dyed-gelatin gel takes place in neutral medium;to give eventually gel dosimeter has a sharp absorbance peak at 635 nm that bleaches quantitatively upon irradiation and the colour change can be measured with UV-VIS spectrophotometer. The useful dose range was 1 - 150 Gy. The radiation chemical yield (G-value) of gel dosimeter was calculated and found to increase by increasing concentration of dye. Post-irradiation storage on the response of gel is discussed. The dose response function, radiation sensitivity, and dependences of the response on environmental factors were studied. 展开更多
关键词 GEL TOLUIDINE Blue O dosimeter γ RAYS and Low Dose
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On-Site Calibration Method of Dosimeter Based on X-Ray Source
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作者 Wenhui Lv Huiping Guo +4 位作者 Ning Lv Chenyang Tian Kuo Zhao Xiaotian Wang Yijie Hou 《World Journal of Nuclear Science and Technology》 2017年第2期93-102,共10页
The real-time monitoring of environmental radiation dose for nuclear fa-cilities is an important part of safety, in order to guarantee the accuracy of the monitoring results regular calibration is necessary. Around nu... The real-time monitoring of environmental radiation dose for nuclear fa-cilities is an important part of safety, in order to guarantee the accuracy of the monitoring results regular calibration is necessary. Around nuclear facilities there are so many environmental dosimeters installed dispers-edly, because of its huge quantity, widely distributed, and in real-time monitoring state;it will cost lots of manpower and finance if it were tak-en to calibrate on standard laboratory;what’s more it will make the en-vironment out of control. To solve the problem of the measurement ac-curacy of the stationary gamma radiation dosimeter, an on-site calibra-tion method is proposed. The radioactive source is X-ray spectrum, and the dose reference instrument which has been calibrated by the national standard laboratory is a high pressure ionization. On-site calibration is divided into two parts;firstly the energy response experiment of dosim-eter for high and low energy is done in the laboratory, and the energy response curve is obtained combining with Monte Carlo simulation;sec-ondly experiment is carried out in the field of the measuring dosimeter, and the substitution method to calibrate the dosimeter is used;finally the calibration coefficient is gotten through energy curve correction. In order to verify the accuracy of on-site calibration method, the calibrated dosimeter is test in the standard laboratory and the error is 3.4%. The re-sult shows that the on-site calibration method using X-ray is feasible, and it can improves the accuracy of the measurement results of the stationary &gamma;-ray instrument;what’s more important is that it has great reference value for the radiation safety management and radiation environment evaluation. 展开更多
关键词 X RAY SOURCE ON-SITE Calibration Energy Response GAMMA RADIATION dosimeter
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Effect of Gold Nanoparticle on Percentage Depth Dose of 18 MV X-Ray in MAGICA Polymer Gel Dosimeter
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作者 Mohammad Mahdavi Mahbobeh Khadem-Abolfazli +1 位作者 Seyed Rabee Mahdi Mahdavi Gholamreza Ataei 《Open Journal of Microphysics》 2013年第2期28-33,共6页
Radiation-sensitive polymer gels are among the most promising three-dimensional dose verification tools and tissue-like phantom developed to date. This study is an investigating of percentage depth dose enhancement wi... Radiation-sensitive polymer gels are among the most promising three-dimensional dose verification tools and tissue-like phantom developed to date. This study is an investigating of percentage depth dose enhancement within the gel medium with the use of conformal distribution gold nanoparticle as contrast agents by high atomic number material. In this work, the normoxic polymer gel dosimeter MAGICA tissue-equivalence was first theoretically verified using MCNPX Monte Carlo code and experimentally by percentage depth dose curves within the gel medium. Then gold nanoparticles (GNPs) of 50 nm diameter with different concentrations of 0.1 mM, 0.2 mM, and 0.4 mM were embedded in MAGICA gel and irradiated by 18 MV photon beam. Experimental results have shown dose increase of 10%, 2% and 4% in 0.1 mM, 0.2 mM and 0.4 mM concentrations, respectively. Simulation results had good agreement in the optimum concentration of 0.1 mM. The largest error between experimental and simulation results was equal to 9.28% stood for 0.4 mM concentration. The results showed that the optimum concentration of gold nanoparticles to achieve maximum absorbed dose in both experimental and simulation was 0.1 mM and so it can be used for clinical studies. 展开更多
关键词 PERCENTAGE DEPTH DOSE Polymer GEL dosimeter Gold Nanoparticles
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Dosimeter Film Based on Ethyl Violet-Bromophenol Blue Dyed Poly(Vinyl Alcohol)
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作者 Seif Ebraheem Moushera El-Kelany 《Open Journal of Polymer Chemistry》 2013年第1期1-5,共5页
Dyed poly(vinyl alcohol) (PVA) films, prepared by a simple technique of casting aqueous solutions of PVA containing a mixture of Ethyl violet and bromophenol blue (EV-BPB) on a horizontal glass plate, are useful as ro... Dyed poly(vinyl alcohol) (PVA) films, prepared by a simple technique of casting aqueous solutions of PVA containing a mixture of Ethyl violet and bromophenol blue (EV-BPB) on a horizontal glass plate, are useful as routine high-dose dosimeter in the 1 - 30 kGy range. The color of films changes from violet to yellow when exposed to gamma radiation. The response of this dosimeter depends up on the concentration of chloral hydrate (CH) in the polymer material. The radiation chemical yield (G-value) of PVA dyed film was calculated and found to increase by increasing concentration of chloral hydrate. Post-irradiation storage on the response of the films are discussed. The overall combined uncertainty (at 2σ) associated with measurement of response (ΔA mm-1) at 600 nm for dose range 1 - 15 kGy is 5.6%. 展开更多
关键词 Ethyl-Violet and Bromo-Phenol Blue Poly(Vinyl Alcohol) Gamma Ray dosimeter
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Comparison of Depth Dose Distributions Using Cerenkov Fiber-Optic Dosimeter and Monte Carlo Simulation for HDR Brachytherapy
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作者 Sang Hun Shin Young Beom Song +4 位作者 Mingeon Kim Hye Jin Kim Wook Jae Yoo Kyoung Won Jang Bongsoo Lee 《Journal of Applied Mathematics and Physics》 2016年第8期1499-1502,共5页
In this study, we fabricated a Cerenkov fiber-optic dosimeter (CFOD) without any scintillator to measure Cerenkov radiation signals owing to gamma-rays. The relative depth dose (RDD) distributions of Ir-192 HDR brachy... In this study, we fabricated a Cerenkov fiber-optic dosimeter (CFOD) without any scintillator to measure Cerenkov radiation signals owing to gamma-rays. The relative depth dose (RDD) distributions of Ir-192 HDR brachytherapy source were obtained by using the CFOD based on a subtraction method and the RDD curve was compared with the simulation result of Monte Carlo N-particle extended transport code (MCNPX). Finally, we demonstrated that the CFOD can be used to measure real-time dose information for HDR brachytherapy. 展开更多
关键词 Cerenkov Fiber-Optic dosimeter Cerenkov Radiation GAMMA-RAY Relative Depth Dose HDR Brachytherapy
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