• 전기학회논문지
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• 제62권10호
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• pp.1421-1424
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• 2013

The electronic equipment which is exposed to high level pulsed radiation is damaged by Upset, Latchup, and Burnout. Those damages come from the instantaneous photocurrent from electron-hole pairs generated in itself. Such damages appear as losses of a power in military weapon system or as a blackout in aerospace equipment and eventually caused in gross loss of national power. In this paper, we have implemented a RDC(Radiation detection and control module) as a part of the radiation protection technology of the electronic equipment or devices from the pulsed gamma radiation. The RDC, which is composed of pulsed gamma-ray detection sensor, signal processors, and pulse generator, is designed to protect the an important electronic circuits from the a pulse radiation. To verify the functionality of the RDC, LM118s, which had damaged by the pulse radiation, were tested. The test results showed that the test sample applied with the RDC was worked well in spite of the irradiation of a pulse radiation. Through the experiments we could confirm that the radiation protection technology implemented with the RDC had the functionality of radiation protection for the electronic devices.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.323-325
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• 2015

본 논문에서는 휴대용 방사능 검출기를 디지털로 구현하기 위하여 아날로그 부 시간영역에서 사용되던 Pulse shaper의 기능을 소프트웨어만으로 커버 할 수 있는 알고리즘을 제안한다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.869-871
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• 2012

고도의 과학기술발전으로 인해 일상생활에서 전자기기의 사용이 급속도로 늘어가고 있다. 또한 태양의 흑점 폭발이나 북한의 핵폭탄, 원전 사고 등으로 인해 방사선에 대한 관심도가 증가하고 있다. 태양으로부터 방출되는 펄스형태의 방사선은 전자장비에 장애를 초래하며 특히 핵폭발 시 전달되는 고준위 펄스 방사선의 경우 전자부품에 오동작 및 불용상태로 까지 영향을 미칠 수 있다. 이러한 방사선 영향에 대한 연구는 국내외에서 다양하게 진행되고 있다. 본 논문에서는 이러한 전자 부품에 영향을 줄 수 있는 펄스방사선 탐지를 위해 Si 기반의 포토다이오드를 제작하고 이를 통해 펄스 입출력 신호에 대한 회로 시뮬레이션과 일반 광원을 이용한 출력 특성을 연구하였다. 본 연구의 결과는 고 에너지의 펄스 방사선 영향으로부터 전자회로를 보호하기 위한 추가적인 모듈의 입력 센서로 활용 될 수 있다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.1023-1026
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• 2013

위 펄스형 방사선에 노출된 전자장비는 전자소자 내부에서 발생되는 전자-정공쌍(EHP)과 이들이 형성한 순간 광전류로 Upset, Latchup, Burn out 과 같은 다양한 피해를 입게 된다. 이와같은 손상은 군무기체계나 우주항공 장비의 경우 군전력 손실이나 장비의 기능정지로 나타나 국가적으로 큰 손실을 초래할 수 있다. 본 연구에서는 펄스형 감마방사선으로 부터 전자장비/소자를 보호하기 위한 방호기술개발의 일환으로 '방사선 감지 및 제어장치'를 구현하고 대표적으로 군장비에 사용되는 전자소자에 대한 기능검증을 시도하였다. 펄스 방사선에 Latchup 및 Burn out 손상특성을 나타내는 LM118 소자에 개발한 '방사선 감지 및 제어장치'를 적용하여 펄스방사선 조사시험을 수행한 결과 LM118이 안전하게 보호됨을 확인하였다.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4350-4356
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• 2023

Radiation detection systems working at high count rates suffer from the overlapping of their output electric pulses, known as pulse pile-up phenomenon, resulting in spectrum distortion and degradation of the energy resolution. Pulse tail extrapolation is a pile-up correction method which tries to restore the shifted baseline of a piled-up pulse by extrapolating the overlapped part of its preceding pulse. This needs a mathematical model which is almost always nonlinear, fitted usually by a nonlinear least squares (NLS) technique. NLS is an iterative, potentially time-consuming method. The main idea of the present study is to replace the NLS technique by an integration-based non-iterative method (NIM) for pulse tail extrapolation by an exponential model. The idea of linear extrapolation, as another non-iterative method, is also investigated. Analysis of experimental data of a NaI(Tl) radiation detector shows that the proposed non-iterative method is able to provide a corrected spectrum quite similar with the NLS method, with a dramatically reduced computation time and complexity of the algorithm. The linear extrapolation approach suffers from a poor energy resolution and throughput rate in comparison with NIM and NLS techniques, but provides the shortest computation time.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.282-282
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• 2000

The analysis of the radiation effect on matter has been performed using stochastic methods. Recently, It was discovered that the detector pulses of radiation can be analysed using deterministic method that utilizes the chaotic behaviour with an attractor found in a noise region. We acquired a time series for pulse tram of Am-241 using scintillation detector and reconstructed a phase space, then performed new analysis for the radiation detection signal by applying embedding theory, Lyapunov exponent, correlation dimension, autocorrelation dimension, and power spectrum.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2123-2125
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• 2005

Ultra wide band electromagnetic energy can be transmitted to a far field by emitting the nanoseconds high voltage Pulse electromagnetic energy via an antenna. This UWB EM energy is expected to be used in post-packing pasteurization of food, detection of buried objects or underground water veins and caves and the treatment of waste water or polluted gas. The nanoseconds pulse forming for UWB generation using 500kV blumlein line and an ultrafast switch is mentioned.

• Journal of Radiation Protection and Research
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• 제42권1호
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• pp.48-55
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• 2017

Background: Simultaneous detection of neutrons and gamma rays have become much more practicable, by taking advantage of good gamma-ray discrimination properties using pulse shape discrimination (PSD) technique. Recently, we introduced a commercial CLYC system in Korea, and performed an initial characterization and simulation studies for the CLYC detector system to provide references for the future implementation of the dual-mode scintillator system in various studies and applications. Materials and Methods: We evaluated a CLYC detector with 95% $^6Li$ enrichment using various gamma-ray sources and a $^{252}Cf$ neutron source, with validation of our Monte Carlo simulation results via measurement experiments. Absolute full-energy peak efficiency values were calculated for gamma-ray sources and neutron source using MCNP6 and compared with measurement experiments of the calibration sources. In addition, behavioral characteristics of neutrons were validated by comparing simulations and experiments on neutron moderation with various polyethylene (PE) moderator thicknesses. Results and Discussion: Both results showed good agreements in overall characteristics of the gamma and neutron detection efficiencies, with consistent ~20% discrepancy. Furthermore, moderation of neutrons emitted from $^{252}Cf$ showed similarities between the simulation and the experiment, in terms of their relative ratios depending on the thickness of the PE moderator. Conclusion: A CLYC detector system was characterized for its energy resolution and detection efficiency, and Monte Carlo simulations on the detector system was validated experimentally. Validation of the simulation results in overall trend of the CLYC detector behavior will provide the fundamental basis and validity of follow-up Monte Carlo simulation studies for the development of our dual-particle imager using a rotational modulation collimator.

• 한국항행학회논문지
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• 제21권6호
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• pp.651-658
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• 2017

방사선이 존재하는 환경에서 무색, 무미, 무촉의 방사선을 검출하기 위한 계측장비는 매우 중요하며 그동안 방사선 계측장비의 개발에 대한 많은 연구들이 있었다. 특히 방사선을 검출한 이후 측정된 검출신호를 손실 없이 효율적으로 처리하기 위해 검출된 미세전류를 전압형태로 정형하고, 이를 정확하게 판독하는 신호처리 부분은 매우 중요하다. 검출된 방사선 신호파형을 판독할 때, 지금까지는 신호의 전압파형을 짧은 시간 동안 일정한 값으로 유지시켜 파형의 크기를 판독한 후, 그 전기적인 값을 방전하고 다음 파형에 대비하는 피크홀드방식을 사용하였다. 이 연구에서는 방사선 검출기에서 측정된 검출신호 전압파형의 판독을 피크홀드방식이 아닌, 전압신호의 파고 정점에 이르는 시간을 포착하여 그 값을 직접 판독하는 방식을 제안한다. 이 방식에 의하면 전압 파고를 일정한 시간동안 유지하거나, 유지된 전압 파고를 초기상태로 만드는 복잡한 과정을 거치지 않고 검출된 방사선 신호를 정확하게 판독할 수 있다는 장점을 가지며, 실제 시뮬레이션을 통하여 이를 검증하였다.

• Nuclear Engineering and Technology
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• 제52권5호
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• pp.1029-1035
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• 2020

The detector suffers from pulse pileup by overlapping of the signals when it was used in high radiation fields. The pulse pileup deteriorates the energy spectrum and causes count losses due to random co-incidences, which might not resolve within the resolving time of the detection system. In this study, it is aimed to propose a new pulse pileup correction method. The proposed method is to correct the start point of the pileup pulse. The parameters are obtained from the fitted exponential curve using the peak point of the previous pulse and the start point of the pileup pulse. The amplitude at the corrected start point of the pileup pulse can be estimated by the peak time of the pileup pulse. The system is composed of a NaI (Tl) scintillation crystal, a photomultiplier tube, and an oscilloscope. A 61 μCi ¹³⁷Cs check-source was placed at a distance of 3 cm, 5 cm, and 10 cm, respectively. The gamma energy spectra for the radioisotope of ¹³⁷Cs were obtained to verify the proposed method. As a result, the correction of the pulse pileup through the proposed method shows a remarkable improvement of FWHM at 662 keV by 29, 39, and 7%, respectively.