提高静电收集法测氡仪灵敏度方法的理论探讨  

Theory Research on Method for Increasing Sensitivity of Radon Monitor Based on Electrostatic Collection Method

作　　者：袁红志[1,2] 赵桂芝[1] 谭延亮[2] 

机构地区：[1]南华大学核科学技术学院,湖南衡阳421001 [2]衡阳师范学院,湖南衡阳421008

出　　处：《衡阳师范学院学报》2014年第6期29-32,共4页Journal of Hengyang Normal University

摘　　要：静电收集法连续测氡仪大多采用半导体探测器作为探测元件,其探测灵敏度是低于闪烁室法及电离室法的,但是其具有能谱测量的独特优势。由于可以通过谱分析排除220 Rn的干扰,基于静电收集法的连续测氡仪得到了广泛的应用。本文对影响静电收集法连续测氡仪探测灵敏度的因素进行了分析,发现提高测量腔体和半导体探测器之间的电压;降低测量腔内的空气的湿度;增大测量腔的体积这三种手段是可以提高静电收集法测氡仪的灵敏度的。并且对这三种方法的机理,效果及适用条件等进行了分析,得到一些有益的结论:当测量腔体和半导体探测器之间的电压高于某一阈值后,继续提高电压,测氡仪的灵敏度不再提高;使用干燥管可以有效的提高探测效率,但是不适合无人值守的环境长期监测;通过增大测量腔的体积来提高探测灵敏度时,灵敏度的提高幅度远小于体积增大的幅度。Most of continuous radon monitor based on electrostatic collection method use a semiconductor detector as the detection element, the detection sensitivity of this kind of continuous radon monitor is lower than that of the scintillation cell and the ionization chamber, but it has unique advantage for the spectroscopy measurement. For the ability to exclude the interference of 220Rn by spectroscopy analysis, this kind of continuous radon monitor based on the electrostatic collection method has been applied in wide range. Analysis of the affecting factors of the detection sensitivity, three means is found to improve the sensitivity of the radon monitor based on electrostatic collection method. The first is to increase the voltage between the wall of electro static collection cell and the semiconductor detector; the second is to reduce the humidity of the air in the cell; the third is to in- crease the volume of the cell. Some useful conclusions are obtained through the analysis of the mechanisms, the effects and the applicable conditions. The sensitivity doesn＇t increase when the voltage between the wall of electrostatic collection cell and the semiconductor detector is higher than a threshold value; reducing the humidity of the air in the cell is not suitable to unattended measure the radon concentration in the environment long time; increasing the volume of the cell, the increasing magnitude of detection sensitivity is much smaller than that of the volume.

关 键 词：测氡仪 静电收集法 灵敏度 

分 类 号：O441.1[理学—电磁学]