基于数字化脉冲处理器的α/β射线甄别方法研究  

Research on α/β Rays Discrimination Method Based on Digital Pulse Processor

作　　者：段再煜 李荐民[1] 胡锐 肖明 DUAN Zaiyu;LI Jianmin;HU Rui;XIAO Ming(Department of Engineering Physics,Tsinghua University,Beijing 100084,China;Unit 92609,Beijing 100077,China;CGN Jiuyuan(Chengdu)Science and Technology Co.,Ltd.,Chengdu 610200,China)

机构地区：[1]清华大学工程物理系,北京100084 [2]92609部队,北京100077 [3]中广核久源(成都)科技有限公司,四川成都610200

出　　处：《原子能科学技术》2021年第8期1478-1484,共7页Atomic Energy Science and Technology

摘　　要：表面污染检测设备多采用ZnS(Ag)和塑料闪烁体组成的复合探测器对α/β射线进行同时测量,其中α/β射线的甄别方法至关重要。传统的甄别方法主要有脉冲幅度甄别法和脉冲宽度甄别法,其受模拟元件参数的影响而甄别稳定性降低。本文基于数字化脉冲处理器对α/β射线进行甄别,在FPGA内部构建电流恢复器、两路方形滤波器、比值计算器计算两路方形滤波器的输出峰值的比值。α/β射线在比值统计图中的不同区间呈高斯分布,由此实现对α/β射线的甄别。结果表明:该甄别方法能实时甄别出α/β射线,甄别品质因子为3.52,串道比均小于0.5%。对α、β探测效率分别不小于57.7%、37%。Most of the surface contamination detection equipments use a phoswich detector composed of ZnS(Ag)and plastic scintillators to simultaneously measure α/β rays,and the discrimination method of α/β rays is critical in this process.The traditional discrimination methods are pulse amplitude discrimination and pulse width discrimination,and the parameter setting of the analog components has a great impact on the stability of the discrimination.In this paper,a digital pulse processor is used to screen α/β rays.A current restorer,a double-channel box filter and a ratio calculator inside the FPGA were constructed to calculate the ratio output peaks of the double-channel box filter.The α/β rays are Gaussian in different intervals in the ratio statistical graph,thus the α/β rays can be discriminated.The results show that this discrimination method can discriminate α/β rays in real time,with the quality factor of 3.52 and crosstalk ratio of less than 0.5%.The detection efficiency for α and β rays is respectively no less than 57.7%and 37%.

关 键 词：复合探测器 α/β测量 粒子甄别 

分 类 号：TL81[核科学技术—核技术及应用]