• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.895-898
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• 1995

베타선 흡수선량의 정밀측정에 사용되는 평판형전리함의 일종인 외삽형전리함(Extrapolation Chamber)으로 베타선 이온화전류의 정확한 측정을 위하여는 이온수집 단면적의 정화한 평가가 필요하다. 이를 위하여 표준 폴리축전기와 표준전압원을 이용한 충전용량 측정법으로 실제 유효 단면적을 구하였으며 측정결과는 기계적 측정치와 약 10.5%의 차이가 있음이 밝혀졌다.

• Journal of Radiation Protection and Research
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• v.9 no.1
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• pp.11-18
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• 1984

A Standard gamma-ray ionization chamber system was developed with a well type ionization chamber and micro current measuring circuit. Micro current was measured by the automatic Townsend balance with stepwise compensation method. For gamma emitting nuclides such as $^{241}Am,\;^{133}Ba,\;^{60}Co,\;^{134}Cs,\;^{137}Cs,\;and\;^{22}Na$ relative calibration factors to $^{226}Ra$ reference source were calculated and detection .efficiency curve was determined as a fudnction of gamma energy.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.318-320
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• 2005

Antioxidation effect of reduced electrolyzed water, which has been known as antiaging agent has been investigated with very simple method. Antioxidation effect of the reaction of linoleic acid with oxygen has been measured and analyzed. Alkaline reduced electrolyzed waters are better effect, rather acidic oxidized electrolyzed waters accelerates oxidation reaction.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.290-291
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• 2005

본 연구에서는 음극전리수가 paraquat에 의한 사람 임파구 DNA의 손상에 미치는 영향을 alkaline comet assay를 사용하여 조사하였다. 또한 음극전리수가 plasmid DNA 손상에 미치는 효과도 조사하였다. 사람 임파구에 다양한 농도의 paraquat을 처리한 후, 음극전리수를 첨가하여 반응시킨 결과 paraquat에 의한 임파구 DNA의 손상은 paraquat 농도증가에 의존적으로 증가하였다. 그러나 음극전리수를 처리한 결과 DNA의 산화적 손상이 paraquat 미처리 대조군 수준으로 거의 다 복구되었다.

• Progress in Medical Physics
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• v.26 no.3
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• pp.178-184
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• 2015

The Markus ionization chamber(R) is a small plane parallel ionization chamber widely used in clinical electron beam dosimetry. Plane parallel chambers were recommended for low energy electron dosimetry with the beam quality at $R_{50}<4.0g/cm^2$ (${\bar{E}}{\approx}10MeV$) according to TRS-398 protocol. However, the quality correction factors ($k_{Q,Q_0}$) of the Markus chamber was not presented in TRS-398 protocol for electron beam quality at $R_{50}<2.0g/cm^2$ (${\bar{E}}{\approx}4MeV$). In this study, the $k_{Q,Q_0}$ factors of the Markus chambers (PTW-34045) for beam qualities at $R_{50}=1.0$, 1.4, 2.0, 2.5, 3.0, and $5.0g/cm^2$ were determined by Monte Carlo calculations (DOSRZnrc/EGSnrc) and the dosimetric formalism of quality correction factor. The derived $k_{Q,Q_0}$ values were evaluated using the produced data based on TRS-398 and TG-51 protocols and known values for the Markus chamber.

• Radiation Oncology Journal
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• v.15 no.1
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• pp.65-69
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• 1997

Purpose : To obtain the actual dose distribution from measured data by doconvolution method using the measured ion chamber response function. Materials and Methods : The chamber response functions for 2 ionization chambers (diameter 5mm, 6.4mm) were measured. and dose Profiles were measured for $10{\times}20cm^2$ field size using two different detectors. The deconvolution of chamber response function from the measured data were performed for these Profiles. The same procedures were repeated for 4MV, 6MV and 1 SMV photon energies. Results : Different dose Profiles were obtained for the same field with the chambers which have the different response functions. Nearly the same results could be obtained with deconvolution for the profiles from various detectors. Conclusion : The effect of the chamber response function can be extracted by deconvolution method. Deconvolved dose profile using various ionization chambers gave better dose distributions. Technical improvements are needed for practical application.

• 대한방사선치료학회:학술대회논문집
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• 1998.03a
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• pp.18-19
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• 1998

• Progress in Medical Physics
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• v.16 no.3
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• pp.111-115
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• 2005

We have designed the multi channel detector for the quality assurance of clinical photon beams. The detector was composed of solid phantom inserted by six plane-parallel ionization chambers at different depth. The chamber as a mini plane parallel chamber was made of carbon coated microfilms. In this study the electrical characteristics of the six chambers in the solid phantom were evaluated using 6 MV photon beam. The leakage currents were less than 0.5 pA, reproducibility was less than 0.5$\%$, linearity was less than 0.5$\%$, and dose rate effect was less than 0.7$\%$. In addition the effect of dose variation from other chambers was estimated to maximum 0.8$\%$ approximately. The developed detector can be used for quality determination in output dosimetry or measurement of percentage depth dose approximately for clinical photon beam.

• Clean Technology
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• v.6 no.1
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• pp.79-84
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• 2000

In this study, to reduce the consumption of chemicals in cleaning processes, Si-wafers contaiminated with metallic impurities were cleaned with electrolyzed water(EW), which was generated by the electrolysis of a diluted electrolyte solution or ultra pure water(UPW). Electrolyzed water could be controlled for obtaining wide ranges of pH and ORP(oxidation-reduction potential). The pH and oxidation-reduction potential of anode water and cathode water were measured to be 4.7 and +1000mV, and 6.3 and -550mV, respectively. To analyze the amount of metallic impurities on Si-wafer surfaces, ICP-MS was introduced. Anode water was effective for Cu removal, while cathode water was more effective for Fe removal.

• 대한방사선방어학회:학술대회논문집
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• 2011.11a
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• pp.118-119
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• 2011