同位素2025，Vol.38Issue(2)：162-169,8.DOI:10.7538/tws.2022.youxian.110
以4πβ-γ符合计数法及4πγ计数法测量133Ba溶液比活度
The Specific Activity Measurement of 133Ba Solution by 4πβ-γ Coincidence Counting Method and 4πγ Counting Method
摘要
Abstract
133Ba is an EC-decay γ-ray source nuclide,which is often used in the calibration of HPGe-γ spectrometer.With the rapid increase in demand for radioactive activity measurement in recent years,it is necessary to establish a fast and accurate 133Ba activity measurement method.Using 4πβ(PC)-γ(NaI)coincidence activity standard measurement device,4πγ well-type NaI activity measurement device and 4πγ high pressure ionization chamber,the 133Ba activity measurement method was studied to confirm whether the 4πγ activity measurement device,which is calibrated passively by MC simulation,can be used to measure the specific activity of 133Ba solution.The specific activity of 133Ba solution was measured by the 4πβ-γ coincidence activity standard measurement device,and the reference value obtained was 614.0 kBq/g,with a relative expanded uncertainty(k=2)of 1.5%.Based on MC simulation,the detection efficiency of 133Ba point source by 4πγ well-type NaI activity measurement device is 98.5%,and the measured value of specific activity of 133Ba solution was 606.1 kBq/g,with a relative expanded uncertainty(k=2)of 0.93%.Based on the standard values from the NPL,the specific activity verified value of 133Ba solution given by a 4πγ high-pressure ionization chamber was 611.0 kBq/g,with a relative expanded uncertainty(k=2)of 1.3%.The|En|of the measured value and the verified value are 0.73 and 0.25 respectively,both of which are less than 1.It can be considered that the results of all three measurement methods were consistent within the uncertainty range.Therefore,it is feasible and reliable to get the specific activity value of 133Ba solution by using the passive efficiency calibration based on MC simulation combine with the 4πγ well-type NaI activity measurement device,which can avoid the complicated process of film sources preparation and efficiency data extrapolation which are necessary for the 4πβ-γ coincidence activity standard measurement device.关键词
133Ba/放射性活度绝对测量/4πβ-γ符合/井型NaIKey words
133Ba/radioactivity absolute measurement/4πβ-γ coincidence/well-type NaI分类
核科学引用本文复制引用
孟令泽,田业辉,朱保吉,夏文..以4πβ-γ符合计数法及4πγ计数法测量133Ba溶液比活度[J].同位素,2025,38(2):162-169,8.基金项目
国家重点研发计划项目(2021YFF0701900) （2021YFF0701900）
