• 한국초전도ㆍ저온공학회논문지
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• 제10권2호
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• pp.27-29
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• 2008

Superconducting RF cavities are being considered for accelerating a proton beam at 700 MHz in the linac of the Proton Engineering Frontier Project (PEFP) and its post-project. Dumbbell fabrication is a mid-process for manufacturing an elliptical superconducting RF cavity. During the dumbbell fabrication, control of the dumbbell length and the $TM010\;{\pi}$ mode frequencies is necessary to build up a desired cavity. A new formula with a perturbation measurement method is used to measure and calculate the frequencies of the individual half-cells of a PEFP low-beta dumbbell, and to tune the frequency and length of the half-cells. In this article, the tuning method and results of the PEFP low-beta dumbbells have been presented.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2006년도 제33회 추계학술대회 발표논문집
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• pp.102-102
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• 2006

• 한국수소및신에너지학회논문집
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• 제33권4호
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• pp.353-362
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• 2022

In this study, water diffusion in proton exchange membrane fuel cell at open circuit voltage (OCV) was analyzed through experiment. First, the reliability of the micro-sensor (SHT31) was verified. It was concluded the micro-sensor has an excellent reliability at 60℃ and 70℃. After the sensor reliability test, the temperature and relative humidity measurement in bipolar-plate was conducted at OCV. To analyze water distribution and water flux, the temperature and relative humidity was converted into dew point. To the end, it was found water concentration affects water diffusion.

• 한국방사선학회논문지
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• 제12권2호
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• pp.133-138
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• 2018

양성자가속기연구센터(KOMAC)의 100-MeV 양성자 선형가속기에서 생성된 고에너지 양성자를 사용하여 천연 텅스텐과 핵반응을 일으켰다. 핵반응을 통해 생성된 다양한 핵종으로 부터의 감마선은 HPGe 검출기 감마선 분광시스템을 사용하여 측정하였다. 감마선 표준선원은 에너지 교정 및 검출기의 효율 측정에 사용되었다. 측정된 스펙트럼에서 관찰된 감마선을 분석한 결과 방사성 핵종은 $^{167}Re$, $^{178}Re$, $^{179}Re$, $^{180}Re$, $^{181}Re$, $^{182}Re$, $^{184}Re$, $^{172}Ta$, $^{174}Ta$, $^{178}Ta$, $^{182}Ta$, $^{184}Ta$, $^{175}W$, $^{176}W$, $^{177}W$ 및 $^{179}W$ 으로 총 16 종류의 핵종이 생성되었다. 이 연구의 결과는 미래의 핵융합, 천체 물리학 및 핵의학 응용 분야에 적용될 것으로 생각된다.

• 한국의학물리학회지:의학물리
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• 제26권1호
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• pp.42-51
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• 2015

양성자 치료 시 양성자 빔을 사용하여 정밀한 치료를 수행하고 환자의 안전을 제고하기 위해서는 인체 내 양성자 빔의 선량 분포를 확인하는 것이 중요하다. 이를 위해 본 연구팀은 이전 연구에서 1차원 배열형 검출기를 종형으로 배치하여 빔 진행방향으로 이동시켜가면서 2차원적인 즉발감마선 분포를 측정하여 양성자 선량 분포와 유사한 분포를 갖는 것을 확인하였다. 본 연구에서는 이를 바탕으로 즉발감마선 이차원분포를 실시간으로 측정하기 위해 이차원 평행다공형 집속 장치, 이차원 배열의 NaI(Tl) 섬광체와 MA-PMT로 이루어진 즉발감마선 이차원분포 측정 장치를 개발하였다. 개발한 즉 발감마선 이차원분포 측정 장치의 성능을 평가한 결과 $^{22}Na$ 감마선원의 에너지 분해능은 $10.9%{\pm}0.23p%$ (0.511 MeV)와 $6.4%{\pm}0.24p%$ (1.275 MeV)로 평가되었으며, $^{137}Cs$은 $9.8%{\pm}0.18p%$ (0.662 MeV)로 평가되었다. 고에너지 Am-Be 선원의 double escape 피크인 3.416 MeV의 에너지 분해능은 $11.4%{\pm}3.6p%$로 평가되었다. 본 측정 장치를 이용하여 45 MeV 양성자 빔을 PMMA에 조사하여 발생한 즉발감마선 이차원분포를 측정한 결과 0.5 nA의 세기의 양성자 빔에서 $9{\times}10^9$ 양성자 조사 시 양성자 선량 분포와 유사한 즉발감마선 이차원분포를 측정할 수 있음을 확인하였다. 추가로 측정한 즉발감마선 이차원분포의 프로파일 분포를 이용하여 양성자 빔의 비정을 평가해 본 결과 $17.0{\pm}0.4mm$로 평가되었고, 실제 비정인 17.4 mm과 굉장히 밀접한 관련이 있음을 확인하였다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.903-904
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• 2005

• 대한원격탐사학회지
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• 제15권4호
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• pp.289-295
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• 1999

Space Physics Sensor (SPS) on-board the KOMPSAT-1 consists of the High Energy Particle Detector (HEPD) and the Ionospheric Measurement Sensor (IMS). The HEPD is to characterize the low altitude high energy particle environment and the effects on the microelectronics due to these high energy particles. It is composed of four sensors: Proton and Electron Spectrometer(PES), Linear Energy Transfer Spectrometer (LET), Total Dose Monitor (TDM), and Single Event Monitor (SEM). 35 MeV proton beam from the medical KCCH cyclotron, at Korea Cancer Center Hospital in Seoul, is used to calibrate the PES. Primary proton beam of 35MeV scattered by polypropylene target is converted to various energy protons according to the elastic collision kinematics. In this calibration, the threshold level of the proton in the PES can be determined and the energy ranges of PES channels are also calibrated.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.208-213
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• 1999

Space Physics Sensor (SPS) on-board the KOMPSAT-1 consists of the High Energy Particle Detector (HEPD) and the Ionospheric Measurement Sensor (IMS). The HEPD is to characterize the low altitude high energy particle environment and the effects on the microelectronics due to these high energy Particles. It is composed of four sensors: Proton and Electron Spectrometer(PES), Linear Energy Transfer Spectrometer (LET), Total Dose Monitor (TDM), and Single Event Monitor(SEM). 35MeV proton beam from the medical KCCH cyclotron, at Korea Cancer Center Hospital in Seoul, is used to calibrate the PES. Primary proton beam of 35MeV scattered by polypropylene target is converted to various energy Protons according to the elastic collision kinematics. In this calibration, the threshold level of the proton in the PES can be determined and the energy ranges of PES channels are also calibrated.

• Journal of Radiation Protection and Research
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• 제41권3호
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• pp.216-221
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• 2016

Background: Very fine radiation-induced aerosol particles are produced in intense radiation fields, such as high-intensity accelerator rooms and containment vessels such as those in the Fukushima Daiichi nuclear power plant (FDNPP). Size measurement of the aerosol particles is very important for understanding the behavior of radioactive aerosols released in the FDNPP accident and radiation safety in high-energy accelerators. Materials and Methods: A combined technique using wire screens and imaging plates was developed for size measurement of fine radioactive aerosol particles smaller than 100 nm in diameter. This technique was applied to the radiation field of a proton accelerator room, in which radioactive atoms produced in air during machine operation are incorporated into radiation-induced aerosol particles. The size of $^{11}C$-bearing aerosol particles was analyzed using the wire screen technique in distinction from other positron emitters in combination with a radioactive decay analysis. Results and Discussion: The size distribution for $^{11}C$-bearing aerosol particles was found to be ca. $70{\mu}m$ in geometric mean diameter. The size was similar to that for $^7Be$-bearing particles obtained by a Ge detector measurement, and was slightly larger than the number-based size distribution measured with a scanning mobility particle sizer. Conclusion: The particle size measuring method using wire screens and imaging plates was successfully applied to the fine aerosol particles produced in an intense radiation field of a proton accelerator. This technique is applicable to size measurement of radioactive aerosol particles produced in the intense radiation fields of radiation facilities.

• 한국의학물리학회지:의학물리
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• 제27권3호
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• pp.162-168
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• 2016

Proton therapy is increasingly being actively used in the treatment of cancer. In contrast to photons, protons have the potential advantage of delivering higher doses to the cancerous tissue and lower doses to the surrounding normal tissue. However, a range shifter is needed to degrade the beam energy in order to apply the pencil beam scanning technique to tumors located close to the minimum range. The secondary neutrons are produced in the beam path including within the patient's body as a result of nuclear interactions. Therefore, unintended side effects may possibly occur. The research related to the secondary neutrons generated during proton therapy has been presented in a variety of studies worldwide, since 2007. In this study, we measured the magnitude of the secondary neutron dose depending on the location of the detector and the use of a range shifter at the beam nozzle of the proton scanning mode, which was recently installed. In addition, the production of secondary neutrons was measured and estimated as a function of the distance between the isocenter and detector. The neutron dose was measured using WENDI-II (Wide Energy Neutron Detection Instruments) and a Plastic Water phantom; a Zebra dosimeter and 4-cm-thick range shifter were also employed as a phantom. In conclusion, we need to consider the secondary neutron dose at proton scanning facilities to employ the range shifter reasonably and effectively.