北航沙河校区土壤中40 K、238 U、232 Th相对含量的实验测量

环境中天然伽马射线主要来源于⁴⁰K以及钍系、铀系和锕系.通过探测伽马射线来识别放射性核素并得到它们的相对含量,是核科学与核技术中的一个重要方法.利用高分辨的高纯锗探测器,北航以及国内部分高校已开设了鉴别环境中放射性核素的实验.在此基础上,本文进一步利用特征γ射线与递次衰变规律,对北航沙河校区土壤中的⁴⁰K、²³⁸U和²³²Th的相对含量进行了测量,结果与普查数据一致.

Determination of relative abundances of 40K,238U and 232Th in the soil at Beihang Shahe campus

The natural gamma rays in environment mainly come from ⁴⁰K and the thorium series,uranium series and actinium series.It is an important method to identify the relevant radioactive nuclides and determine the relative abundances in nuclear science and technology.At Beihang and some domestic universities,a lab experiment is developed to identify the radioactive nuclides in environment via characteristic gamma rays by using the high-resolution high-purity germanium detectors.In this paper,a new lab experiment to deduce the relative abundances of ⁴⁰K,²³⁸U,and ²³²Th in the soil at Beihang Shahe Campus is reported,which is done by using their characteristic gamma rays and successive decays.The results are consistent with the previous data measured in 1985.