水中总α放射性测量中样品质量厚度变化的影响及校正

辐射防护 ›› 2023, Vol. 43 ›› Issue (6): 566-575.

水中总α放射性测量中样品质量厚度变化的影响及校正

杜云武, 邓晓钦, 毕朝文, 朱杰, 王亮, 曾奕, 郭旭影, 王艳, 王茜

四川省辐射环境管理监测中心站,成都 610031

收稿日期:2022-09-19 出版日期:2023-11-20 发布日期:2023-12-25
作者简介:杜云武(1970—),男,1995年毕业于四川大学原子核物理与核技术专业,教授级高级工程师。E-mail:353658296@qq.com
基金资助:
四川省生态环境厅2021年度生态环境保护科研重点支持课题(2021HB05)。

Influence and correction of sample mass thickness variation for total alpha radioactivity measurement in water

DU Yunwu, DENG Xiaoqin, BI Chaowen, ZHU Jie, WANG Liang, ZENG Yi, GUO Xuying, WANG Yan, WANG Qian

Sichuan Provincial Radiation Environment Management and Monitoring Center Station, Chengdu 610031

Received:2022-09-19 Online:2023-11-20 Published:2023-12-25

摘要/Abstract

摘要： 通过试验和蒙特卡罗模拟了不同质量厚度的²⁴¹Am、天然α核素探测效率,分析探测效率、计数率、探测效率校正因子、探测效率倒数与质量厚度的关系以及探测效率、有效饱和厚度与能量的关系。研究表明:水中总α放射性测量,需要用探测效率校正因子、分支比和成分比例进行α核素探测效率修正;质量厚度7 mg/cm²,平衡铀探测效率校正因子为0.96;质量厚度2 mg/cm²,平衡钍探测效率校正因子为1.01、平衡²²⁶Ra-²²²Rn探测效率校正因子为1.05;质量厚度大于4 mg/cm²,天然铀、4%浓缩铀、97%浓缩铀探测效率校正因子基本恒定,分别为0.39、0.39、0.47;质量厚度小于0.510 mg/cm²,单个α核素辐射源的探测效率校正因子均大于0.70;质量厚度大于有效饱和厚度,探测效率的倒数与质量厚度成线性关系;有效饱和厚度与α射线能量成线性关系。

关键词: 天然α核素, 质量厚度, 探测效率, 校正因子, 有效饱和厚度

Abstract: The detection efficiency of ²⁴¹Am and natural alpha radionuclide with different mass thickness was analyzed through experiments and Monte Carlo simulation. The relationship between mass thickness and detection efficiency, count rate, detection efficiency correction factor, as well as reciprocal detection efficiency were analyzed. And the relationship between detection efficiency, effective saturation thickness and energy were also analyzed. The results show that the detection efficiency of alpha radionuclide in water needs to be corrected by the detection efficiency correction factor, branch ratio and component ratio. When the mass thickness is 7 mg/cm², the equilibrium uranium detection efficiency correction factor is 0.96; With a mass thickness of 2 mg/cm², the equilibrium thorium detection efficiency correction factor is 1.01, and the equilibrium ²²⁶Ra-²²²Rn detection efficiency correction factor is 1.05. When the mass thickness is greater than 4 mg/cm², the detection efficiency correction factors of natural uranium, 4% enriched uranium and 97% enriched uranium are basically constant, which are 0.39, 039 and 0.47, respectively. When the mass thickness is less than 0.510 mg/cm², the detection efficiency correction factor of single alpha radionuclide radiation source is greater than 0.70. When the mass thickness is greater than the effective saturation thickness, the reciprocal of the detection efficiency is linear with the mass thickness. The effective saturation thickness is linearly related to the alpha ray energy.

Key words: natural alpha radionuclides, mass thickness, detection efficiency, correction factor, effective saturation thickness

中图分类号:

X830

杜云武, 邓晓钦, 毕朝文, 朱杰, 王亮, 曾奕, 郭旭影, 王艳, 王茜. 水中总α放射性测量中样品质量厚度变化的影响及校正[J]. 辐射防护, 2023, 43(6): 566-575.

DU Yunwu, DENG Xiaoqin, BI Chaowen, ZHU Jie, WANG Liang, ZENG Yi, GUO Xuying, WANG Yan, WANG Qian. Influence and correction of sample mass thickness variation for total alpha radioactivity measurement in water[J]. RADIATION PROTECTION, 2023, 43(6): 566-575.