• Title/Summary/Keyword: Pulse radiation

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Pulse pileup correction method for gamma-ray spectroscopy in high radiation fields

  • Lee, Minju;Lee, Daehee;Ko, Eunbie;Park, Kyeongjin;Kim, Junhyuk;Ko, Kilyoung;Sharma, Manish;Cho, Gyuseong
    • Nuclear Engineering and Technology
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    • v.52 no.5
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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.

Peak detection algorithm at time domain of full-digital portable radiation detection system (휴대용 방사능 검출기의 시간 영역에서의 최고값 검출 알고리즘)

  • Hwang, Dong Gyu;Kim, Young Kil
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.323-325
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    • 2015
  • The purpose of the thesis is to suggest the algorithm that can be covered only by software instead of the function of pulse shaper that was used in the time domain. In order to implementing portable radiation detector for digital.

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Some aspects of scintillation mechanism in organic molecular dielectrics

  • Galunov, N.Z.;Grinev, B.V.;Tarasenko, O.A.;Martynenko, E.V.
    • Journal of Radiation Protection and Research
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    • v.30 no.2
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    • pp.85-89
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    • 2005
  • Aspects of the scintillation mechanism in organic systems obtained on the base of precise measurements of the radioluminescence pulse shape are discussed. It shown that the process of scintillation light pulse formation is mainly determined by initial conditions of exited states generation.

The development of laser system for cancer (암치료용 레이저 시스템 개발)

  • 이동진;김주명;김선학;임현수
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.08a
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    • pp.154-155
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    • 2001
  • A laser system for therapy of cancer is proposed in this paper. In order to accuracy and statistical output control we used the constant current control method and designed the power source to protect the resonator from the over -current, rush-current and electrical fault. The most important things are the radiation type for cancer therapy in laser system, we developed the radiation type of cw, pulse, and burst pulse. The experimental result show that laser beam power increase linearly from 100mW to 300mW for input current increasing and the exposure time.

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A Study on Characteristics of Diode Detecter for Verification of Radiation Therapy (방사선 치료위치 검증을 위한 다이오드 검출기의 특성에 관한 연구)

  • 이동훈;김윤종;지영훈;이동한;홍승홍
    • Proceedings of the IEEK Conference
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    • 2000.06e
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    • pp.106-109
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    • 2000
  • The diode characteristics for therapy radiation sensor have been studied by irradiating therapy radiation from the MM22 microtron accelerator. Signal processing has been performed in the pulse mode which can process the signal fast. We have designed integrator, peak detector and synchronization circuit to detect diode signal in the pulse mode for implementation of portal image. We also read the diode signal by A/D board and displayed the peak value with LabView program. Because the quality of portal image obtained by film in the case of therapy radiation is much worse than that of diagnostic film, Digital radiography system by rectifier diode detector was suggested for portal Image.

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A Study on Implementation of Transient Radiation Effects on Electronics(TREE) Assessment System (전자소자의 과도방사선피해 평가체계 구축 연구)

  • Lee, Nam-Ho;Hwang, Young-Gwan;Kim, Jong-Ryul;Jeong, Sang-Hun;Oh, Seung-Chan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.10
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    • pp.2329-2334
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    • 2012
  • In this paper, we performed a study of damage assessment model development to analyze the initial nuclear pulse radiation damage to semiconductor devices for military weapon systems. At first we modeled(M) the nuclear pulse radiation and diode device, and simulated(S) the output characteristics of the device to the input. Then the manufactured diodes which had the same characteristics with the modeled one were irradiated to the similar pulsed type radiation and their output signals were measured simultaneously. Error between the M & S results and the measured values of the analysis was 22.9%. Through the error value we could confirm that the damage assessment model simulated the TREE effects with a quite accuracy.

A new approach for modeling pulse height spectra of gamma-ray detectors from passing radioactive cloud in a case of NPP accident

  • R.I. Bakin;A.A. Kiselev;E.A. Ilichev;A.M. Shvedov
    • Nuclear Engineering and Technology
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    • v.54 no.12
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    • pp.4715-4721
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    • 2022
  • A comprehensive approach for modeling the pulse height spectra of gamma-ray detectors from passing radioactive cloud in a case of accident at NPP has been developed. It involves modeling the transport of radionuclides in the atmosphere using Lagrangian stochastic model, WRF meteorological processor with an ARW core and GFS data to obtain spatial distribution of radionuclides in the air at a given moment of time. Applying representation of the cloud as superposition of elementary sources of gamma radiation the pulse height spectra are calculated based on data on flux density from point isotropic sources and detector response function. The proposed approach allows us to obtain time-dependent spectra for any complex radionuclide composition of the release. The results of modeling the pulse height spectra of the scintillator detector NaI(Tl) Ø63×63 mm for a hypothetical severe accident at a NPP are presented.

Characteristics of the Electromagnetic Fields Radiated from Stepped Leaders Just Prior to Lightning Return Strokes (계단상 리더에 의해서 방사된 귀환뇌격 직전의 전장과 자장 파형의 특성)

  • 이복희;이동문;정동철;장근철;이승칠;정광희
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.1
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    • pp.35-41
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    • 2003
  • In this paper statistics on the radiation field waveforms produced by stepped leaders just prior to lightning return strokes were described. As a parameter of stepped leader pulse characteristics, the time interval between the final leader pulse and return stroke peak, the pause time between stepped leaders, the ratio of the final leader peak to the return stroke peak and the stepped leader pulse width at half maximum were examined. The average time intervals between the final leader pulse and return stroke peak were about 16.2 and 14.8$mutextrm{s}$ for the positive and negative polarities, respectively. When the stepped leader approaches closely to ground, the time interval between leader steps was decreased and the mean value was about 17$mutextrm{s}$, and the present results were in reasonable agreement with the data observed in Florida and Japan. The large fraction of the ratios of the final stepped leader pulse to the lightning return stroke peak were distributed over the range from 5 to 35% and in average the ratio of the final leader pulse to the return stroke peak was 17.4$\pm$11.9% for the positive and 18.5$\pm$9.4% for the negative electric field waveforms. In addition, the mean pulse widths at half maximum of the stepped leaders are 1.4Us with a standard deviation of 0.9 for the positive Polarity and 2.2us with a standard deviation of 1.2 for the negative polarity, respectively.

A Study on Time Series Analysis for the Detector Pulses of Radiation (방사선 검출신호의 시계열 분석에 관한 연구)

  • 홍석붕;정종은;김용균;문병수;권기호
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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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.

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