2015年土壤比对样品放射性γ能谱分析

Analysis of radioactivity in soil samples using γ-spectrometry in 2015 intercomparison

目的 分析实验室比对样品中放射性核素比活度。方法 通过参加2015年中国疾病预防控制中心辐射防护与核安全医学所组织的全国放射性核素γ能谱分析比对，利用高纯锗（HPGe）γ能谱仪测量样品，分别采用效率曲线法和相对比较法分析土壤比对样品中放射性核素232Th、40K和137Cs的比活度。结果 利用两种分析方法求得结果与参考值的相对偏差均 〈 5%，相对比较法获得的测量值与参考值的相对偏差 〈 4%。结论 效率曲线法和相对比较法均可以完成比对样品中放射性核素的测定，且相对比较法优于效率曲线法。

Objective To analyze the specific activity of radionuclides based on laboratory intercomparison. Methods Intercomparison of the measurements of radioanuclides 232Th, 40K and 137Cs in soil samples, organized by National Institute for Radiological Protection, China CDC, was conducted using HPGe γ-spectrometry and the method of relative comparison and efficiency curve, respectively. Results The relative deviations were all less than 5% compared to the reference values in the conditions of both relative comparison method and efficiency curve method used, respectively. The relative deviations to the reference values were less than 4% for the relative comparison method. Conclusions Both the relative comparison method and the efficiency curve method can be used to measure the activity of radionuclides in the intercomparison samples, and the latter is superior to the former.