基于HPGe谱仪的气溶胶滤膜考核样中总α或总β放射性活度估算  

Estimation of totalαor totalβactivities in the test samples with aerosol filter membranes based on HPGe spectrometer

作　　者：陈诚 罗茂丹 王亮[1] 王玉兰 王茜[1] 徐僳 舒奕嘉 李广 CHEN Cheng;LUO Maodan;WANG Liang;WANG Yulan;WANG Qian;XU Su;SHU Yijia;LI Guang(Radiation Environmental Management and Monitoring Center of Sichuan Province,Chengdu 611130,China;Sichuan Radiation Environmental Assessment and Treatment Co.,Ltd.,Chengdu 611130,China;Chongqing Radiation Environment Supervision and Management Station,Chongqing 400015,China)

机构地区：[1]四川省辐射环境管理监测中心站,成都611130 [2]四川省辐射环境评价治理有限责任公司,成都611130 [3]重庆市辐射环境监督管理站,重庆400015

出　　处：《核技术》2021年第7期17-23,共7页Nuclear Techniques

基　　金：生态环境部2021年度国控网络辐射环境监测技术方法研究重点支持课题(No.2021-5)资助。

摘　　要：在2020年生态环境部辐射环境监测质量考核中,针对气溶胶滤膜中总放射性考核样品,使用无源效率刻度的高纯锗(HPGe)γ谱仪,通过核素识别和定量测量,间接估算出考核样品中总α和总β放射性活度,并利用气溶胶滤膜γ多核素标准样品和自制气溶胶滤膜薄参考样品,验证了分析方法的可行性。考核分析结果显示:总α活度考核样的测量值为61.2 Bq,总β活度考核样的测量值为73.2 Bq,其不确定度分别为U_(α)=6.6%(k=2)和U_(β)=3.6%(k=2),通过Z比分数方法评价,考核分析结果均合格。此外,还对实验室无源效率刻度软件LabSOCS(Laboratory Sourceless Calibration Software)中的参数设置、γ谱本底扣除及核素γ谱能量选择和γ级联辐射校正等三方面内容进行了讨论,为该方法应用于气溶胶总放射性分析提供有益的参考。[Background]Sichuan Radiation Environmental Management and Monitoring Center participated in the radiation environmental monitoring quality assessment organized by the Ministry of Ecology and Environment in 2020.Two total radioactivity standards prepared by Eckert&Zigler Analytics Corporation were used for test samples in this assessment.[Purpose]This study aims to establish an indirect method for the estimation of totalαor totalβactivities in the test samples based on HPGe spectrometer,and to provide some useful references for the application of this method in the analysis of aerosol total radioactivity.[Methods]The low background BE6530 HPGe spectrometer produced by Canberra(US)was used to identify nuclides of test samples and to collect theirγspectra data.Laboratory sourceless calibration software(LabSOCS)was used to calibrate the efficiency of the HPGe spectrometer.Aγ-rays standard sample with multiple nuclides in an aerosol filter membrane and a self-made reference sample in an aerosol filter membrane were applied to confirm the reliability of the method established in this work.[Results]A formula is derived for the estimation of totalαor totalβactivities byγspectra data.The measurement results and uncertainties of totalαand totalβactivities in the two test samples are 61.2 Bq and 73.2 Bq,6.6%(k=2)and 3.6%(k=2),respectively.The results are all qualified after the Z-score evaluation.In addition,the parameter setting in LabSOCS,background deduction ofγspectra,γpeak selection andγcascade radiation correction are discussed,which provides a useful reference for the application of this method in the total radioactivity analysis.[Conclusions]The indirect method established in this work has a good accuracy and can be applied in the analysis of aerosol total radioactivity.

关 键 词：HPGe谱仪 无源效率刻度 核素分析 总α和β考核样 

分 类 号：TL99[核科学技术—核技术及应用]