连续测量法同时测定空气中^(222)Rn子体与^(220)Rn子体浓度

Simultaneous and consecutive measurements of radon decay products and thoron decay products in air

222Rn子体浓度可通过测定母体222Rn浓度,根据平衡因子进行大致估算.由于220Rn及其子体之间并不存在相对稳定的平衡因子,因此,若要准确获得220Rn子体浓度,需借助仪器通过累积、连续测量进行测定.文章应用我国不常见的工作水平监测仪(working level monitor),同时实现空气中222Rn子体与220Rn子体的累积连续测量,从而计算得到两者浓度.通过借助液体闪烁仪的参照比较,验证了此法同时测量空气中222Rn子体与220Rn子体的准确性与可靠性.

Generally, the concentration and its related dose of radon decay products in air could be calculated by means of measuring radon, on the basis of equilibrium factor between radon and its decay products. But rath- er differently, the measurement of thoron in air is not as easy as radon. There exists no relatively stable equilib- rium factor between thoron and its decay products. Therefore, the exact concentration as well as inhalation dose from thoron decay products should be determined and assessed through direct consecutive measurement of decay products, based on scientific equipments. Specifically, the paper describes a novel method of using working lev- el monitor which is widely used in Germany, to simultaneously and consecutively measure the radon decay prod- ucts and thoron decay products in air. The results by adopting this new method to simultaneously measure the radon decay products and thoron decay products were in good agreement with those by the liquid scintillation counter, indicating the precision and reliability of the proposed new method.