一种多路低本底α测量仪设计

Design of Multi Channel Low Background Alpha Measuring Instrument

文中介绍一种可同时测量5个样品总α的低本底测量仪的设计思路、电路原理和结构特征。在分析了低本底α测量的特点和原理,以及对测量仪的功能要求的基础上,对仪器电路、软件进行了设计,使其对于241Amα源的2π方向探测效率≥68%时,本底计数率≤0.002 3 cm^(-2)·min^(-1),实现了本底超低、操控简单、质量轻、体积小和性价比高的目的。仪器主要用于地质勘查^(210)Po分析时样品多情况下的检测,也适用于水质监测和环境放射性评价等领域微弱α放射性的检测。

This paper introduced the design idea, the circuit principle and the structure characteristic of a low background measuring instrument which can measure the total alpha of five samples simultaneously.Based on the analysis of the characteristics and principles of low background alpha measurement, and the functional requirements of the measuring instrument, then the circuit, and the software were designed, the α-sourees 241 Am 2π direction detection efficiency was higher than 68%, the background count rate was not more than 0.002 3 cm^-2·min^-1, it achieved the purpose of ultra low background, simple control, light weight, small volume and high cost.The instrument is mainly used for the detection of samples in ^210Po analysis of geological exploration, but also for weak α radioactivity detection in water quality monitoring and environmental radioactivity evaluations and other fields.