环境空气测氚用正比计数器研制及性能测试  

Design and test of proportional counter for measurement of tritium in air

作　　者：吕洋 朱保吉 李元桥 吕晓侠[1] 朱亨 徐利军[1] 林敏[1] LYU Yang;ZHU Baoji;LI Yuanqiao;LYU Xiaoxia;ZHU Heng;XU Lijun;LIN Min(China Institute of Atomic Energy,Beijing 102413 China)

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《中国辐射卫生》2024年第6期626-630,共5页Chinese Journal of Radiological Health

基　　金：国家重点研发计划项目(2022YFF0607300);核设施安全重要辐射参量计量检测和评价关键技术研究。

摘　　要：目的 空气中氚浓度的直接、连续测量多采用电离室作为探测器,但由于弱电流测量技术的限制,其测量灵敏度较差,有必要研制一种用于环境空气中氚气测量的正比计数器。方法 本研究通过材料、结构等方面进行正比计数器的设计,并对其稳定性、坪曲线、探测效率、能谱进行测试。结果 正比计数管的变异系数为3.14%,满足标准中要求的变异系数<15%;坪长260 V,坪斜0.80%/100V,满足坪斜<1%/100V的要求;对氚的探测效率达到68.02%;能谱测量结果表明该正比计数器产生的氚信号与本底信号具有明显区别,氚在能谱中的分布更加集中,可通过能谱测量来降低氚气活度测量时的本底计数率。结论 研制的正比计数管可为空气中氚的直接、连续测量提供参考依据。Objective Ionization chamber detector is commonly used for direct and continuous measurement of tritium concentration in the air.However,the measurement sensitivity is low due to the limitations of weak current measurement technology.It is necessary to develop a proportional counter for measuring tritium in the air.Methods This study involved the design of a proportional counter,considering various factors such as materials and structure.The stability,plateau curve,detection efficiency,and energy spectrum of the counter were tested.Results The coefficient of variation of the proportional counter was 3.14%,which met the standard requirement of being less than 15%.The plateau length was 260 V and the plateau slope was 0.80%/100V,which met the requirement of being less than 1%/100V.The tritium detection efficiency reached 68.02%.The energy spectrum measurement indicated a significant difference between tritium signal generated by the proportional counter and background signal,and the distribution of tritium in the energy spectrum was more concentrated.The background counting rate during tritium gas activity measurement could be reduced through energy spectrum measurement.Conclusion The proportional counter can provide a reference for the direct and continuous measurement of tritium in the air.

关 键 词：低活度水平氚 正比计数管 直接测量 坪曲线 探测效率 

分 类 号：TL814[核科学技术—核技术及应用]