大面积薄窗流气式正比计数器工作电压设置研究

摘要

A 1000 cm2 thin-window flow gas proportional counter is used as the detector for a large area con -tamination measuring instrument .In order to realize the simultaneous measurement of αand βray, based on the anticoincidence -PHD ( pulse height discrimination ) technology , aiming at the problem of obvious interfer-ence ratio varying with the increase of working voltage , this article has analyzed the causation , and put forward a working voltage setting method subject to the interference ratio .In this way, the accuracy of αand βray measurement could be guaranteed .Experimental results has proved that the feasibility of this method , which ap-propriately met the requirement of national standard .%大面积α／β表面污染测量仪采用1000 cm2薄窗流气式正比计数管作为探测器。为实现α／β射线的同时测量，在反符合—脉冲幅度甄别技术的基础上，针对β信号随电压升高而串道明显的实际问题，分析了原因，提出了串道比约束下的探测器工作电压设置方法，以此保证α／β测量的准确性。实验证明，方法可行并符合国家标准的规定。