摘要
^(90)Sr是一种纯β衰变核素,但由于其衰变子体^(90)Y半衰期仅为64 h,会对^(90)Sr活度准确定值带来影响,鉴于其本身的性质,^(90)Sr的分析方法比较复杂,本研究采用液闪三双两双符合计数法(TDCR)对^(90)Sr放射性活度进行测量,在^(90)Sr-^(90)Y子母体平衡状态下,测量^(90)Sr和^(90)Y的总计数,TDCR总效率计算按照两种核素效率加和计算,TDCR效率的计算先采用BataShape程序计算^(90)Sr和^(90)Y能谱,利用编写的效率计算程序基于自由参数模型计算β粒子在闪烁液中的计数效率,得到^(90)Sr/^(90)Y的效率曲线,结合实验测量的TDCR值与效率曲线,实现^(90)Sr活度的绝对测量,相对标准不确定度为0.36%,为环境监测和核安全领域提供了一种可靠的工具。
^(90)Sr is a pureβdecay nuclide,but because its decay progeny^(90)Y half-life is only 64 hours,it will have an impact on the accurate determination of^(90)Sr activity,given its own nature,the analysis method of^(90)Sr is relatively complex,the liquid scintillation triple-to-double coincidence ratio method(TDCR)is used to measure the^(90)Sr radioactivity activity,in the state of equilibrium of the^(90)Sr-^(90)Y daughter.The total counts of^(90)Sr and^(90)Y were measured,and the calculation of the total TDCR efficiency will be calculated according to the sum of the two nuclide efficiencies.The calculation of the TDCR efficiency was first performed by using the BataShape program to calculate the^(90)Sr and^(90)Y energy spectra,and the efficiency of countingβ-particles in the scintillating liquid based on the free-parameter model by using the efficiency calculation program written and obtaining the efficiency curves of^(90)Sr/^(90)Y,combined with the experimental results of the TDCR values and efficiency curves are combined to achieve the absolute measurement of^(90)Sr activity with a relative standard uncertainty of 0.36%,which provides a reliable tool for environmental monitoring and nuclear safety fields.
作者
田业辉
朱保吉
夏文
徐利军
TIAN Yehui;ZHU Baoji;XIA Wen;XU Lijun(China Institute of Atomic Energy,Beijing 102413,China)
出处
《同位素》
2025年第3期284-291,共8页
Journal of Isotopes
基金
国家重点研发计划项目(2021YFF0701900)资助。
关键词
三双两双符合计数法
锶-90
放射性活度
环境监测
核安全
triple-Double coincidence counting method
strontium-90
radioactivity
environmental monitoring
nuclear safety
