• The Journal of Korean Society for Radiation Therapy
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• v.12 no.1
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• pp.1-7
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• 2000

• Progress in Medical Physics
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• v.2 no.1
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• pp.17-28
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• 1991

Generally, it is an accurate radiation measurement technique for processors fo thermoluminescent dosimenters(TLDs) to characterize each element they use by producing element correction factors(FCFs). TLDs are classified into three groups such as reference. control, and field TLDs. Reference TLDs are used only for the production of ECFs for the control and field TLDs. They are kept locked in a safe place except when it is necessary to use a subset of them to produce ECFs for the control and field TLDs. The ECF of a given element is a measure of the response of the element relative to the mean response of an arbitrarily selected group of reference elements. As TLDs are used in the field, their relative responses to radiation might be decreased due to muliple readings and physical abuse. Therefore, the producditon of ECFs are performed initially and periodically during the field use. This element correction method provides an excellent tool to examine new TLDs and to monitor the reliability of old TLDs. This paper discuss the 10 step procedures developed to produce and examine ECFs.

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

• Journal of the Korean Society of Radiology
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• v.6 no.6
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• pp.499-505
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• 2012

The purpose of this study was to find out the difference of radiation dose value through energy, exposure number, fluoroscopy time, the number of days of exposed scatter X-ray when TLD and OSLD is used in diagnostic radiology. The difference of value were measured by relative ratio and interval. Energy makes high relative ratio of TLD($1.81{\pm}0.41$) than OSLD($1.40{\pm}0.26$), exposure number makes high of OSLD($1.40{\pm}0.26$) than TLD($2.10{\pm}0.10$). There are no significant differences between relative ratio of TLD and OSLD in fluoroscopy time and the number of days of exposed scatter X-ray. But interval of relative ratio in the number of days of exposed scatter X-ray was narrowed in less 0.2. That means, the measurement of scatter X-ray could more confident in TLD and OSLD than the measurement of direct ray. In conclusion, we have to recognize the relative ratio of TLD and OSLD could be vary depending on exposed condition of radiation. And in some cases, double test of TLD and OSLD get more creditable results of dose value.

• Nuclear Engineering and Technology
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• v.2 no.4
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• pp.229-239
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• 1970

Various thermoluminescent properties of Korean natural quartz for possible use in ${\gamma}$-ray dosimetry has been studied. If the heating is exactly linear, ${\gamma}$-irradiated radiation sensitive (type 1) $\alpha$-quartz can yield a glow curve of single peak, hence glow peak height could be taken as a ${\gamma}$-dose for its dosimetry. Quartz crystal dosimeter exhibited the linearity of thermoluminescent intensity in the range from about 2$\times$10$^{3}$R to 2$\times$10$^{6}$ R, and also had an advantage of low fading because of the high peak temperature (300$\pm$4$0^{\circ}C$). The pulverized quartz sample having the grain size of 0.3<ø<0.9mm showed the linearity of T. L. intensity in the range from 50R to 2$\times$10$^3$R. Therapeutic application of the pulverized sample on the correct measurement of the absorbed dose in a body region of a cancer patient seems to be successful.

• Journal of the Korean Society of Radiology
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• v.7 no.6
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• pp.415-418
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• 2013

Thermoluminescent dosimeter utilizes the fact that when irradiated specimen is heated up, some part of the absorbed energy is emitted from the specimen as light with longer wavelength. This research aims at analyzing the glow curves of four TLD-100 exposed to a magnetic field and those of other four TLD-100 not exposed to one by treating them with heat and irradiating them, which are commonly used as thermoluminescent dosimeter, in the same condition. As the result of the experiment, regarding the electrons captured by irradiation, some of the electrons of lower traps were combined with positive holes of valence band through the exposure to a magnetic field, and the peak size decreased by 48%. The reduction in the size of the lower traps caused the TLD-100 exposed to a magnetic field to display a low level of dose. In addition, low traps estimated activation energies are 1.6 eV and 1.5 eV.

• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.216-217
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• 2009

• Nuclear Engineering and Technology
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• v.26 no.3
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• pp.381-388
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• 1994

Recently, the American National Standards Institute (ANSI) had made some changes in the radiation sources specified from those in the original performance test criteria ANSI N13. 11-1983. In case or beta category, in addition to the high-energy $^{90}$ Sr/$^{90}$ Y beta source, the $^{204}$ Tl source was added because many workplaces have significant levels of lower energy betas. In this study, the performance or the Teledyne PB-3 personnel dosimetry system in the fields of $^{204}$ Tl and $^{90}$ Sr/ $^{90}$ Y beta was investigated using the PTB beta secondary standard sources. The new beta correction function of PB-3 personnel dosimetry system for $^{204}$ Tl beta was also developed in this response experiment. The results show that the Teledyne PB-3 personnel dosimetry system is very effective for $^{90}$ Sr/ $^{90}$ Y beta dose assessment. In case of $^{204}$ Tl beta radiation, however, the results of simple performance test indicated that the use of beta correction factor(=2.088) which was recommanded by manufacturer may result in unexpectable overestimation of delivered dose by about 60%, while the use of developed beta correction function could measure the delivered doses in errors of 15%.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.875-881
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• 1995

원자력 연구소는 국제원자력기구(IAEA/RCA) 주관하에 1990년부터 1993년 사이 3차에 걸쳐 실시한 개인선량계에 대한 국제상호비교에 참여하였다. 국제 상호비교에 참여하여 사용된 개인선량계는 방사선작업종사자에 대한 외부방사선으로부터 피폭관리를 위하여 기 사용중인 Taedyne Isotope 사의 PB-3타입의 열형광선량계이며 선량계판독용으로 Tdedyne 9150자동판독기를 사용하였다. 본 논문에는 3차에 걸쳐 국제상호비교결과를 요약하였으며 저 에너지의 엑스선에 경우를 제외하고 모든 조사방사선에 대해 0.78에서 1.07사이에 상대비율로 결과를 나타내었다. 또한 미국기준 ANSI Nl 3.11에 의해 성능을 시험한 결과 모든 조사방사선장에 대해서 허용기준 0.5이하를 나타내었다.

• Nuclear Engineering and Technology
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• v.7 no.4
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• pp.285-293
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• 1975

A result of the study to determine the depth-dose distribution along the central axis of a polyethylene sphere in diameter of 30cm is described. Depth-dose distribution in the polyethylene sphere for broad beam of monoenergetic photons has been experimentally determined with thermoluminescent dosimeter as a cavity dosimeter. The conversion of dose absorbed in the LiF TLD to dose in the surrounding medium was carried out on the basis of Burlin's generalized cavity theory. Presented in graphical forms are the results obtained. The maximum absorbed doses in the sphere were observed at the depth of about 0.3cm and 0.5cm from the surface of the sphere for the gamma-rays of $^{137}$ Cs and $^{60}$ Co, respectively.