• Journal of Digital Contents Society
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• v.16 no.3
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• pp.463-470
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• 2015

The angular dependence of active dosimeters, EPD, is analysed and compared with that of passive dosimeters, OSLD, after evaluating their relative response and uncertainty of measurement, where it is known that the personal use of them has been increased recently. There appeared a minor variation for average relative response of OSLD in the horizontal and vertical directions within the range $0^{\circ}{\sim}{\pm}90^{\circ}$, which are 0.97 and 0.95 respectively. The variations of angular dependence in the same situations with OSLD are 0.65 and 0.62, respectively, which also reveals a negligible effect on the overall uncertainty. EPDs within the interval $0^{\circ}{\sim}{\pm}60^{\circ}$ for horizontal and vertical directions are 0.94 and 0.97, respectively. These satisfy the requirements of IEC 61526. Uncertainties about the dependence of direction from horizontal and vertical directions are 0.44, 0.40, respectively. The impact of these uncertainties on the overall uncertainty was negligible. However, we observed a significant change in reactivity: the relative reactivities for $+90^{\circ}$ and $-90^{\circ}$ from the horizontal direction are 0.60, 0.37, while that form vertical direction is 0.06. The direction dependence of OSLD was superior to EPD in the range of $0^{\circ}{\sim}{\pm}90^{\circ}$. There appeared a rapidly changing structural features in EPD response for a certain direction. Therefore, we conclude that concurrent use of passive dosimeters and auxiliary dosimeter provides accurate data for personal dose measurements.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.06a
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• pp.397-398
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• 2009

• Journal of the Korean Society of Radiology
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• v.14 no.6
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• pp.841-848
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• 2020

In the field of radiation therapy using photon beams and electron beams, since each patient has a different sensitivity to radiation, skin side effects may occur even at the same dose. Therefore, if there is a risk of excessive dose to the skin, a dosimeter is attached to verify whether the correct dose is being investigated. However, since the skin dosimeter checks the attachment site visually by measuring a point dose, it is difficult to confirm an accurate dose distribution. As a result, the measurement and simulation errors of the material HgI₂ in the 6 MV photon beam were 3.73% and 5.24%, respectively, at the minimum thickness of 25 ㎛, and the material PbI₂ was 4.73% and 5.65%, respectively. On the other hand, as a result of the 6 MeV electron beam, the measurement and simulation errors of the material HgI₂ were 1.35% and 1.12%, respectively, at a minimum thickness of 25 ㎛, and the material PbI₂ showed relatively low attenuation error, 1.67% and 1.20%, respectively. Therefore, it was evaluated that the thickness of the photon beam within 25 ㎛ and the electron beam within 100 ㎛ is suitable to have a reduction rate error within 5%. This study presents a new research direction for a flexible dosimeter attached to the human body that is required in clinical practice and the construction conditions of a future skin dosimeter.

• Progress in Medical Physics
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• v.16 no.2
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• pp.77-81
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• 2005

To determine the appropriate method out of various available methods to measure build-up doses, the measurements and comparisons of depth doses of build-up region including the surface dose were executed using the Attix parallel-plate ionization chamber, the Markus chamber, a cylindrical ionization chamber, and a diode detector. Based on the measurements using the Attix chamber, discrepancies of the Markus chamber were within $2\%$ for the open field and increased up to $3.9\%$ in the case of photon beam containing the contaminant electrons. The measurements of an cylindrical ionization chamber and a diode detector accord with those of the Attix chamber within $1.5\%\;and\;1.0\%$ and after those detectors were completely immersed in the water phantom. The results suggest that the parallel-plate chamber is the best choice to measure depth doses in the build-up region containing the surface, however, using cylindrical ionization chamber or diode detector would be a reasonable choice if no special care is necessary for the exact surface dose.

• 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.

• Journal of the Korean Vacuum Society
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• v.4 no.1
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• pp.26-31
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• 1995

본 연구에서는 Co/Si 계에 대한 이온선 혼합실험을 온도와 이온선량을 변수로 하여 실시하였고, Co/Si 계에 대한 상형성 과정을 금속/Si 계에 대한 이온선 혼합시의 비정질상 및 결정상 형성예측 모델(ADF Model)과 초기 결정상 예측 모델(PDF Model)을 이용하여 해석하였다. 이온선 혼합은 80KeV 가속기를 이용하여 상온$-400^{\circ}C$의 온도 범위에서 1.0X1015Ar+/$\extrm{cm}^2$-2.0X1016Ar+/$\textrm{cm}^2$의 이온선량을 변화시키면서 실험하였으며 상분석은 투과전자현미경(TEM)과 X선 회절 분석을 이용하였다. Co/Si 계에서 이온선 혼합시 형성되는 초기 결정상은 Co2Si이며 이온선량의 증가에 따라 CoSi로 상전이하였다. 이러한 실험 결과는 비정질상 및 결정상 형성 예측 모델(ADF model)과 초기 결정상 예측모델(PDF model)의 예측결과와 매우 잘 일치하고 있다. 이상의 연구 결과로부터 ADF 모델과 PDF모델을 이용하여 박막에서 형성되는 상을 보다 정확히 예측할 수 있음을 알 수 있었다.

• Radioisotope journal
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• v.9 no.3
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• pp.59-62
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• 1994

• Radioisotope journal
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• v.10 no.4
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• pp.72-74
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• 1995

• Radioisotope journal
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• v.9 no.4
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• pp.46-49
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• 1994

• Journal of Radiation Protection and Research
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• v.40 no.4
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• pp.261-266
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• 2015

As performance of electronic personal dosimeter (EPD) used for auxiliary personal dosimeter in nuclear power plants (NPPs) has been being continuously improved, we investigated application cases in Korea and other countries and also tested it in NPPs to assess the performance of EPD for external radiation dosimetry. Result of performance tests done in domestic NPPs was similar to those obtained by IAEA in cooperation with EURADOS (IAEA-TECDOC-1564). In addition, EPD/TLD dose ratio has shown similar tendency of EPD/Film-badge dose ratio from the research by the Japan Atomic Power Company (JAPC) and EPD provided more conservative value than TLD or Film-badge. Although some EPD's failures have been discussed, EPD has shown continuous improvement according to the report of Institute of Nuclear Power Operation (INPO) and data from domestic NPPs. In conclusion, It is considered that the general performance of EPD is adequate for external radiation dosimetry compared with that of TLD, providing appropriate performance checking procedure and alternative measures for functional failure.