基于脉冲宽度分析的实时数字堆积排除方法研究  

Real time digital pile-up reject based on pulse width analysis method

作　　者：黄强[1] 杨磊[1] 陈禛[1] 徐小恒 张猛超 李东仓[1] HUANG Qiang;YANG Lei;CHEN Zhen;XU Xiaoheng;ZHANG Mengchao;LI Dongcang(School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学核科学与技术学院,兰州730000

出　　处：《核技术》2018年第9期35-41,共7页Nuclear Techniques

摘　　要：高计数率下的核能谱获取中,随机脉冲的堆积效应造成获取到的核能谱分辨率变差。为了有效抑制脉冲堆积对γ谱仪分辨率的不利影响,基于高速全波形数字化采样技术,文中提出了脉冲宽度分析方法应用于高计数率下的核脉冲实时堆积判别和拒绝。采用仿核脉冲信号源论证了该堆积拒绝方法的可行性,也使用了Na I闪烁体探测器对137Cs和60Co两种放射源进行实验测试。结果表明:该方法可以有效实时识别出脉冲后沿和前沿堆积情况,在高计数率下可以有效改善数字γ谱仪分辨率。[Background] The pile-up effect of stochastic pulse could have detrimental impact to the nuclear energy spectrum acquisition system, and make the relevant nuclear energy spectral resolution even worse at high count rates. [Purpose] ＆ [Methods] In order to restrain the adverse effect, we proposed pulse-width analysis method, which was based on the high speed digital sampling technique of full-pulse waveform, to real time distinguish and reject nuclear pulse pile-up signals at high count rates. In this sense, experiments were performed from both signal source and radioactive source to verify this method. [Results] The feasibility of this method had been proved on the basis of signal source of imitating nuclear radiation pulse. In the meantime, the γ rays of 60C0 and 137Cs radioactive source were measured by using NaI scintillation detector under the experiment platform. [Conclusion] The results illustrate that pulse-width analysis method can continuously monitor the situation of pulse post-stacking events and leading-edge stacking events, and also has significant effect on improving the resolution of digital γ spectrometer at high count rates.

关 键 词：堆积判别 脉冲宽度分析 高计数率 数字γ谱仪 

分 类 号：TL817.2[核科学技术—核技术及应用]