高灵敏度的放射性气溶胶连续监测仪  

A high sensitive radioactive aerosol continuous monitor

作　　者：李爱武[1] 张志龙[1] 傅翠明[1] 卢正永[1] 贾明雁 苏旭军 黄勇 王善强 

机构地区：[1]中国辐射防护研究院 [2]289810部队

出　　处：《核电子学与探测技术》2001年第5期356-361,共6页Nuclear Electronics & Detection Technology

摘　　要：介绍了一种高灵敏度的放射性气溶胶连续监测仪 (CAM- 1型 )。该监测仪利用人工放射性气溶胶和天然放射性气溶胶粒度分布特性的不同 ,采用气溶胶粒度分离采样的方法 ,在采样过程中首先去除了天然放射性本底的大部分 ;进而在样品测量中利用 α能谱分析法和改进的 α/ β比值法 ,进一步消除了天然放射性本底的影响。通过上述措施 ,不仅实现了 α气溶胶和 β气溶胶的同时监测 ,而且极大地提高了仪器的监测灵敏度。介绍了 CAM- 1型放射性气溶胶连续监测仪的工作原理、结构设计、运行实验和监测灵敏度的估算。实验表明 ,在普通天然本底条件下 ,仪器的监测灵敏度为 0 .0 15 Bq/ m3(对 α放射性气溶胶 )和 1.0 Bq/ m3(对 β放射性气溶胶 ) ;在高氡本底 (10 3～ 10 4 Bq/ m3)情况下 ,仪器的监测灵敏度则分别为 0 .15 Bq/ m3(对 α放射性气溶胶 )和 10 Bq/ m3(对 β放射性气溶胶 )。监测仪报告数据的时间间隔通常 30 min,也可按需要任意设置。A radioactive aerosol monitor with high sensitivity is described in this paper. Most of nature radioactive aerosol particles to obstruct obtaining an ideal sensitivity of the radioactive aerosol monitor areseparated from artificial radioactivity aerosol particles in the particle size selective sampling by using for the difference of particle size between them. And in radioactivity measurement of the sampler, the natural background is still further eliminated by the α energy discrimination method and the developed α/β ration method. The monitoring sensitivity of the monitor is exceedingly improved, owing to take above means, as well as both α aerosol and β aerosol can be monitored simultaneously by one monitor. The principle of operation , construction , field test and determination of detection limit and so on are introduced in the paper. The test data have shown that, for general nature background, the minimum detection limit (MDL) of the monitor is respectively 0.015Bq/m 3 (for α aerosol) and 1.0 Bq/m 3 (for β aerosol). The MDL will be respectively 0.15 Bq/m 3 (for α aerosol) and 10 Bq/m 3 (for β aerosol) if the concentration of daughter aerosol is came up to 10 3 10 4 Bq/m 3 .The monitor has the functions that find out operation breakdowns of the monitor. The time interval of reporting the monitoring data is reported once every 30 minus while the time interval of reporting data may be set up arbitrarily.

关 键 词：放射性气溶胶 采样 监测 灵敏度 a谱分析法 结构 a/β比值法 监测仪 放射性监测 

分 类 号：X837[环境科学与工程—环境工程] X859