• Journal of Radiation Protection and Research
• /
• v.41 no.2
• /
• pp.179-183
• /
• 2016

Background: As an important detecting device, TLD is a widely used in the radiation monitoring. It is essential for us to study the property of detecting element. The aim of this study is to calculate the thermo-luminescence efficiency of TL elements. Materials and Methods: A batch of thermo-luminescence elements were irradiated by the filtered X-ray beams of average energies in the range 40-200 kVp, 662 keV $^{137}Cs$ gamma rays and then the amounts of lights were measured by the TL reader. The deposition energies in elements were calculated by theory formula and Monte Carlo simulation. The unit absorbed dose in elements by photons with different energies corresponding to the amounts of lights was calculated, which is called the thermo luminescent efficiency (${\eta}^{(E)}$). Because of the amounts of lights can be calculated by the absorbed dose in elements multiply ${\eta}^{(E)}$, the ${\eta}^{(E)}$ can be calculated by the experimental data (the amounts of lights) divided by absorbed dose. Results and Discussion: The deviation of simulation results compared with theoretical calculation results were less than 5%, so the absorbed dose in elements was calculated by simulation results in here. The change range of ${\eta}^{(E)}$ value, relative to 662 keV $^{137}Cs$ gamma rays, is about 30% in the energy range of 33 keV to 662 keV, is in accordance by the comparison with relevant foreign literatures. Conclusion: The ${\eta}^{(E)}$ values can be used for updating the amounts of lights that are got by the direct ratio assumed relations with deposition energy in TL elements, which can largely reduce the error of calculation results of the amounts of lights. These data can be used for the design of individual dosimeter which used TLD-2000 thermo-luminescence elements, also have a certain reference value for manufacturer to improve the energy-response performance of TL elements by formulation adjustment.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1999.05a
• /
• pp.366-366
• /
• 1999

• International Journal of Contents
• /
• v.8 no.2
• /
• pp.52-59
• /
• 2012

This study uses digital imaging and communications in medicine (DICOM) files acquired after CT scan to obtain the absorbed dose distribution inside the body by using the patient's actual anatomical data; uses geometry and tracking (Geant)4 as a way to obtain the accurate absorbed dose distribution inside the body. This method is easier to establish the radioprotection plan through estimating the absorbed dose distribution inside the body compared to the evaluation of absorbed dose using thermo-luminescence dosimeter (TLD) with inferior reliability and accuracy because many variables act on result values with respect to the evaluation of the patient's absorbed dose distribution in diagnostic imaging and the evaluation of absorbed dose using phantom; can contribute to improving reliability accuracy and reproducibility; it makes significance in that it can implement the actual patient's absorbed dose distribution, not just mere estimation using mathematical phantom or humanoid phantom. When comparing the absorbed dose in polymethly methacrylate (PMMA) phantom measured in metal oxide semiconductor field effect transistor (MOSFET) dosimeter for verification of Geant4 and the result of Geant4 simulation, there was $0.46{\pm}4.69%$ ($15{\times}15cm^2$), and $-0.75{\pm}5.19%$ ($20{\times}20cm^2$) difference according to the depth. This study, through the simulation by means of Geant4, suggests a new way to calculate the actual dose of radiation exposure of patients through DICOM interface.

• The Journal of the Korea Contents Association
• /
• v.12 no.12
• /
• pp.329-334
• /
• 2012

For the dosimetry of the radiation workers, film badge, Thermo Luminescent Dosimeter (TLD), and glass dosimeter are being used and recently, there is a growing trend of using Optically Stimulated Luminescence Dosimeter (OSLD) in the world. However, OSLD is only being applied some of the field in Korea and there has been almost no study made related to OSLD. Thus, the accumulated radiation dose of TLD and OSLD that have been most frequently used in the field was compared in the radiation workers of nuclear medicine and their working areasfor 3 months. As a result, the average surface dose showed 0.85 mSv difference with 1.27 mSv for TLD and 2.12 mSv for OSLD while having 0.73 mSv difference for the average depth dose with 1.33 mSv for TLD and 2.06 mSv for OSLD. The surface dose and depth dose of OSLD showed statistically significant result with higher measurement (p<0.05).

• Journal of the Korean Society of Radiology
• /
• v.8 no.4
• /
• pp.171-180
• /
• 2014

In this study, the authors attempted to measure the skin dose by irradiating the actual dose on to the TLD(Thermo-Luminescence Dosimeter) and EBT3 Film used as the In-vivo dosimetry after planning the same treatment as the actual patient on a Phantom, because the erythema or dermatitis is frequently occurred on the patients' skin at the time of the proton therapy of medulloblastoma patient receiving the proton therapy. They intended to know whether there is the usefulness for the dosimetry of skin by the comparative analysis of the measured dose values with the treatment planned skin dose. The CT scan from the Brain to the Pelvis was done by placing a phantom on the CSI(Cranio-spinal irradiation) Set-up position of Medulloblastoma, and the treatment Isocenter point was aligned by using DIPS(Digital Image Positioning System) in the treatment room after planning a proton therapy. The treatment Isocenter point of 5 areas that the proton beam was entered into them, and Markers of 2 areas shown in the Phantom during CT scans, that is, in all 7 points, TLD and EBT3 Film pre-calibrated are alternatively attached, and the proton beam that the treatment was planned, was irradiated by 10 times, respectively. As a result of the comparative analysis of the average value calculated from the result values obtained by the repeated measurement of 10 times with the Skin Dose measured in the treatment planning system, the measured dose values of 6 points, except for one point that the accurate measurement was lacked due to the measurement position with a difficulty showed the distribution of the absolute dose value ${\pm}2%$ in both TLD and EBT Film. In conclusion, in this study, the clinical usefulness of the TLD and EBT3 Film for the Enterance skin dose measurement in the first proton therapy in Korea was confirmed.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.21 no.2
• /
• pp.86-93
• /
• 2017

Purpose In this study, radiation workers who work in nuclear medicine department were analyzed to find the cause of differences of radiation exposure from General Characteristic, Knowledge, Recognition and Conduct, especially females working on nuclear medicine radiation, in order to pave the way for positive defense against radiation exposure. Materials and Methods The subjects were 106 radiation workers who were divided into two groups of sixty-four males and forty-two females answered questions about their General Characteristic, Knowledge, Recognition, Conduct, and radiation exposure dose which was measured by TLD (Thermo Luminescence Dosimeter). Results The results of the analysis revealed that as the higher score of knowledge and conduct was shown, the radiation exposure decreased in female groups, and as the higher score of conduct was shown, the radiation exposure decreased in male groups. In the correlation analysis of female groups, the non-experienced in pregnancy showed decreasing amount of radiation exposure as the score of knowledge and conduct was higher and the experienced in pregnancy showed decreasing amount of radiation exposure as the score of recognition and conduct was higher. In the regression analysis on related factors of radiation exposure dose of nuclear medicine radiation workers, the gender caused the meaningful result and the amount of radiation exposure of female groups compared to male groups. In the regression analysis on related factors of radiation exposure dose of female groups, the factor of conduct showed a meaningful result and the amount of radiation exposure of the experienced in pregnancy was lower compared to the non-experienced. Conclusion The conclusion of this study revealed that radiation exposure of female groups was lower than that of male groups. Therefore, male groups need to more actively defend themselves against radiation exposure. Among the female groups, the experienced in pregnancy who have an active defense tendency showed a lower radiation exposure. Thus, those who have never been pregnant need to have a more active defensive conduct for the future possibility of pregnancy.

• Journal of the Korea Safety Management & Science
• /
• v.12 no.4
• /
• pp.73-80
• /
• 2010

The purpose of this study was to investigate the actual conditions of radiation safety supervision in animal clinics using inspection standard of X-ray generator for diagnosis. The surveys for inspection standard system, equipment condition, and safety supervision were carried out in 18 animal clinics randomly. The inspection standard included reproducibility of dose exposure, kVp, mAs, collimator accuracy test, collimator luminance test, X-ray view box luminance test, grounding system equipment test and external leakage current test. The surveys of equipment condition and safety supervision used one-on-one interview with 5 points measurement. As a result, 44.44% of reproducibility of dose exposure was proper, 81.25% of kVp test was good, and 100% of mAs test was appropriate. Also, 66.66% of collimator accuracy test was proper, 61.11% of collimator luminance test was good, 53.13% of X-ray view box luminance test was suitable. In addition, only 5.55% of grounding system equipment and ground resistance was proper, 63.64% of external leakage current test was appropriate in grounding system equipment test. The 100mA electric capacity of X-ray generator for diagnosis was popular with 44.44%, and its 55.56% was purchased used equipment. Monthly average of less than 50 times (61.11%) was top frequency in use, and no animal clinic had a thermo-luminescence dosimeter(TLD). The 16 animal clinics with radiation safety zone and 2 without radiation safety zone were appeared.

• Journal of Radiation Protection and Research
• /
• v.38 no.1
• /
• pp.37-43
• /
• 2013

In case of neutron dose measurement using TLDs (thermo-luminescence dosimeters), because the neutron energy dependence of the TLD is very high, the calibration of the energy response according to the characteristics of the neutron spectrum of workplace is required. In the present study, the ambient dose equivalent rates inside and around the Long-Counter (neutron detector) with narrow and complex inside in the neutron field of $^{252}Cf$ were evaluated. The calibration factors to account for the neutron energy dependence of TLDs were established for both the bare and $D_2O$ modulated $^{252}Cf$ neutron beams, respectively. The values of the TLD's measurement were compared with the computational results of the MCNPX (Monte Carlo N-Particles transport code). When using the two calibration factors of the TLD than a single calibration factor, the measured and the calculated values at the point of verification outside and inside the Long-Counter were in more good agreement. This results show that TLD should be calibrated in the reference neutron field similar to workplace situation.

• Journal of radiological science and technology
• /
• v.39 no.2
• /
• pp.209-225
• /
• 2016

In this study, radiation workers who work in nuclear medicine department were analyzed to find the cause of differences of radiation exposure from General Characteristic, Knowledge, Recognition and Conduct, especially females working on nuclear medicine radiation, in order to pave the way for positive defense against radiation exposure. The subjects were 106 radiation workers who were divided into two groups of sixty-four males and forty-two females answered questions about their General Characteristic, Knowledge, Recognition, Conduct, and radiation exposure dose which was measured by TLD (Thermo Luminescence Dosimeter). The results of the analysis revealed that as the higher score of knowledge and conduct was shown, the radiation exposure decreased in female groups, and as the higher score of conduct was shown, the radiation exposure decreased in male groups. In the correlation analysis of female groups, the non-experienced in pregnancy showed decreasing amount of radiation exposure as the score of knowledge and conduct was higher and the experienced in pregnancy showed decreasing amount of radiation exposure as the score of recognition and conduct was higher. In the regression analysis on related factors of radiation exposure dose of nuclear medicine radiation workers, the gender caused the meaningful result and the amount of radiation exposure of female groups compared to male groups. In the regression analysis on related factors of radiation exposure dose of female groups, the factor of conduct showed a meaningful result and the amount of radiation exposure of the experienced in pregnancy was lower compared to the non-experienced. The conclusion of this study revealed that radiation exposure of female groups was lower than that of male groups. Therefore, male groups need to more actively defend themselves against radiation exposure. Among the female groups, the experienced in pregnancy who have an active defense tendency showed a lower radiation exposure. Thus, those who have never been pregnant need to have a more active defensive conduct for the future possibility of pregnancy.