摘要
α-放射性气溶胶取样膜是放射性气溶胶监测系统的重要组成部分,选择过滤效率高、自吸收小及高表面收集特性的滤膜,将有利于提高监测速度和被测α的能量分辨率,后者有利于α辐射体的准确监测和成分分析。研究选用三种不同类型滤膜采集氡子体气溶胶,测定了滤膜对气溶胶取样的过滤效率、自吸收因子、表面收集特性以及阻力与流量的关系参数。在气溶胶浓度、取样流量和取样时间相同的条件下,平均孔径为0.8μm的混合纤维素酯滤膜的过滤效率最高,自吸收损失较小;孔径为0.4μm的重离子微孔滤膜的自吸收损失最小,表面收集特性优越,对于提高监测分辨率具有优势;玻璃纤维滤膜的阻力小,适合大流量取样条件下采用。
Filter for α-radioactive aerosol sampling is one of the important parts in radioactive aerosol detection.Filter with high efficiency,low self-absorption and high-performed surface collection will improve the speed of monitoring and energy resolution of α.In this study,3 different types of filters were chosen for sampling of natural radon daughter aerosol.The parameters of collection efficiency,self-absorption,surface collection characteristics and flow rate under the same resistance were measured.In the same condition of the aerosol concentration,sampling flow rate and sampling time,the membrane filter which is made of mixed cellulose ester with the mean pore radius of 0.8 μm,has the highest filter efficiency and less self-absorption;heavy-ion microporous membrane with pore radius of 0.4 μm has minimal self-absorption and superior surface collection,which is important in improving the α energy resolution;the glass fiber filter has the lowest resistance,suiting for large flow rate in sampling.
出处
《核电子学与探测技术》
CAS
CSCD
北大核心
2012年第1期116-119,共4页
Nuclear Electronics & Detection Technology
关键词
α-放射性气溶胶
重离子微孔滤膜
自吸收
过滤效率
α-radioactive aerosol
heavy-ion microporous membrane
self-absorption
filter efficiency
