• Title/Summary/Keyword: Pulse radiation

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A readout method using pulse peak-time capture for radiation detectors (펄스의 피크시각 포착을 이용한 방사선 검출기의 신호처리 방법)

  • Kim, Jong-ho;Kwon, Young-mok;Hong, Hyoung-pyo;Che, Gyu-shik
    • Journal of Advanced Navigation Technology
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    • v.21 no.6
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    • pp.651-658
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    • 2017
  • There were many studies on the development of radiation measuring instruments to detect the presence of radiation. In particular, the signal processing method and treatment without loss of the detection signal are very important. The common feature for these studies is the peak-hold method that keeps the peak value of input signal uniform for a short time, readouts its value, discharges electrical value, and then waits for next signal. We propose the new methodology to capture the pulse peak value from the radiation detector and read the value directly other than peak-hold method. This method has merit of accurate reading the input signal pulse peak value without complicate process of holding for a period or initializing of input signal, and then be verified to be adequate through simulation of actual example.

Radiation Effects on PWM Controller of DC/DC Power Buck Converter (DC/DC 전력 강압 컨버터의 PWM 제어기 방사선 영향)

  • Lho, Young-Hwan
    • Journal of the Korean Society for Railway
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    • v.15 no.2
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    • pp.116-121
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    • 2012
  • DC/DC switching power converters produce DC output voltages from different DC input sources. The converter is used in regenerative braking of DC motors to return energy back in the supply, resulting in energy savings for the systems containing frequent stops. The DC/DC converter is composed of a PWM-IC (pulse width modulation integrated circuit) controller, a MOSFET (metal-oxide semi-conductor field-effect transistor), an inductor, capacitors, and resistors, etc. PWM is applied to control and regulate the total output voltage. In this paper, radiation shows the main influence on the changes in the electrical characteristics of comparator, operational amplifier, etc. in PWM-IC. In the PWM-IC operation, the missing pulses, the changes in pulse width, and the changes of the output waveform are studied by the simulation program with integrated circuit emphasis (SPICE) and compared with experiments.

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.