4πβ(PC)-γ符合法测量60Co核素活度及不确定度评定  

Evaluation of Co Nuclide Activity and Uncertainty by 4πβ(PC)-γCoincidence Method

作　　者：唐豪 范富有 梁珺成[2] 钟科 朱宝吉 姚顺和 王仁波[5] TANG Hao;FAN Fu-you;LIANG Jun-cheng;ZHONG Ke;ZHU Bao-ji;YAO Shun-he;WANG Ren-bo(Nuclear Power Institute of China,Chengdu,Sichuan 610000,China;National Institute of metrology,Beijing 100029,China;University of Science and Technology of China,Hefei,Anhui 230027,China;National Defense Science and Technology Industry Ionizing Radiation Level I Metering Station,Beijing 102413,China;East China University of Techology,Nanchang,Jiangxi 330013,China)

机构地区：[1]中国核动力研究设计院,四川成都610000 [2]中国计量科学研究院,北京100029 [3]中国科学技术大学,安徽合肥230027 [4]国防科技工业电离辐射一级计量站,北京102413 [5]东华理工大学,江西南昌330013

出　　处：《计量学报》2020年第11期1425-1430,共6页Acta Metrologica Sinica

基　　金：国家重点研发计划项目(2017YFF0205405);国家自然科学基金(11505179)。

摘　　要：4πβ(PC)-γ符合方法主要用于实现β-γ级联衰变放射性核素活度的绝对测量,该方法一般测量VYNS(聚氯乙烯-醋酸乙烯共聚物)薄膜源样品,但其制备过程复杂。对制源工艺进行了优化,用4πβ(PC)-γ数字符合系统,对改进工艺制成的薄膜源进行了测量。用效率外推法获得的测量结果显示,新制60Co源的β表观效率达到93%,10个样品源的比活度测量结果在0.1%范围内一致。通过在数字符合软件上改变符合分辨时间、死时间与延迟时间,研究了符合参数选择对于测量结果的影响,评估了60Co核素活度测量的不确定度。The 4πβ(PC)-γcoincidence method is mainly used to achieve the absolute measurement ofβ-γcascade decay radionuclide activity.This method is usually used to measure the VYNS film source sample,but its preparation process is complicated.The source preparation process is optimized.The film source produced by the improved process is measured using a 4πβ(PC)-γdigital coincidence system.The measurement results obtained by the efficiency extrapolation method show that the apparent efficiency of the new 60Co source reaches 93%,and the specific activity measurement results of the 10 sample sources are consistent within the range of 0.1%.By changing the resolution time,dead time and delay time on the digital compliance software,the influence of the parameter selection on the measurement results is studied,and the uncertainty of the 60Co nuclide activity measurement is evaluated.

关 键 词：计量学 60Co核素活度 4πβ(PC)-γ符合法 绝对测量 制源工艺 效率外推 不确定度 

分 类 号：TB98[一般工业技术—计量学]