气球法氡气测量中滤膜性能的实验研究  

Performance research of filter in radon measurement with balloon method

作　　者：杨强[1] 葛良全[1] 王尔奇[2] 周晓剑[2] 

机构地区：[1]成都理工大学地学核技术重点实验室,成都610059 [2]环境保护部核与辐射安全中心,北京100082

出　　处：《核技术》2014年第6期66-71,共6页Nuclear Techniques

基　　金：国家863计划课题"高精度能谱探测仪器研发"(No.2010AA061803);中国地质调查局工作项目(No.1212011120186)资助

摘　　要：滤膜是气球测氡仪的重要组成部分,选择过滤效率高、自吸收小的滤膜,不仅可以提高取样速度,更可有效减小测量误差。根据氡及其子体在滤膜上收集的物理过程,能够推导出空气滤膜上氡子体的收集和衰变随时间的变化规律。通过实验,在标准氡室中对不同材料的三种微孔滤膜过滤效率和自吸收因子关键指标进行了测试。实验表明,在同等厚度条件下,聚四氟乙烯滤膜和尼龙滤膜的过滤效率比常用玻璃纤维滤膜高,其自吸收情况也较玻璃纤维膜小;从气阻情况分析,聚四氟乙烯滤膜气阻最低,尼龙滤膜气阻最大;对常用玻璃纤维滤膜,通过增加膜厚度能够有效改善其性能指标。不仅为气球法测氡仪滤膜的选择提供了重要依据,也适用于其他滤膜测氡装置。Background： Filter membrane is an important part of the balloon emanometer. The membrane of high filtration efficiency but little self-absorption can not only improve the sampling rate, but also reduce the measurement error effectively. Purpose： The experiment aims to compare the performance of three different filter membrane materials. Methods： Based on the radon and its progeny collecting physical processes on the membrane, we deduced the collection of radon in filters and its decay variation with time. Through the experiment, the filtration efficiency and self-absorption factor of the three different membranes have been tested. Results： When the thickness is almost the same, the filtration efficiency of Polytetrafluoroethylene （PTFE） filter and nylon filter is higher than that of commonly used glass fiber filter and its self-absorption is better than that of glass fiber membrane. The air resistance of PTFE filter is the best. It can effectively improve the performance by increasing thickness of the glass fiber filter membrane. Conclusion： This is not only a good reference for the selection of filter membrane in radon measurement with balloon method, but also applicable to radon-measuring devices with other methods.

关 键 词：自吸收 过滤效率 气球法测氡 滤膜 

分 类 号：TL84[核科学技术—核技术及应用]