新型低本底α/β测量系统设计  

The New Design of a Low Background α/β Measurement System

作　　者：杨志杰[1,2] 梁珺成[2] 杨豪[1,2] 贺海江 侯胜利[1] 王南萍[1] YANG Zhi- jie;LIANG Jun-cheng;YANG Hao;HE Hai-jiang;HOU Sheng-li;WANG Nan-ping(School of Geophysics and Information Technology,China University of Geosciences,Beijing 100083,China;National Institute of Metrology,Beijing 100029,China)

机构地区：[1]中国地质大学地球物理与信息技术学院,北京100083 [2]中国计量科学研究院,北京100029

出　　处：《核电子学与探测技术》2019年第2期228-234,共7页Nuclear Electronics & Detection Technology

摘　　要：设计了一套新型低本底α/β测量系统。该系统采用ZnS( Ag)薄板复合蝮料闪烁体作为主探测器,平板形塑料闪烁体作为反符合探测器,实现样品中总α和总β的同时测最。利用ARM架构的MCU作为系统运行核心,FPGA硬件电路作为数据采集单元,基于脉冲宽度甄别方法实现测最系统的α/β脉冲甄别。对该系统进行了主要性能测试,测试结果表明:测量α粒子时,本底为0.003 min^-1·cm^-2,对239Pu α标准平面源的探测效率为92. 5%,α对β道的串道比为0.87%;测量β粒子时,本底为0.072 min^-1· cm……-2,对吟90Sr-90Yβ标准平面源的探测效率为62.0%,β对α道的串道比为0.03%。A new low background α/β measurement system was designed. The system uses ZnS ( Ag) thin plate composite plastic scintillator as the main detector, and the flat plastic scintillator as the anti coincidence detector to achieve simultaneous measurement of total α and total β in the same sample. The MCU of the ARM architecture is used as the core of the system, and the FPGA hardware circuit is used as the data acquisition unit to realize the α/β pulse discrimination based on the pulse width discrimination method. The main performance test of the system was carried out. The experiment result shows that for a particles, the background is 0.003 min^-1·cm^-2, and the detection efficiency of the 239 Pu a standard plane source is 92.5%. The cross-channel ratio of α-to-β channel is 0.87%;for β particles, the background is 0.072 min^-1·cm^-2, the detection efficiency for the 90Sr-90 Yβ standard plane source is 62.0%, and the cross-channel ratio of β-to-α is 0.03%.

关 键 词：低本底测量 α/β测量 脉冲宽度甄别 

分 类 号：TB98[一般工业技术—计量学]