气溶胶中210Bi对210Po测量结果推算的影响

Influence of 210Bi on calculation of 210Po activity concentration in air aerosol

气溶胶中210Pb和210Po两者之间浓度处于不平衡状态,被核素210Bi隔开,210Bi初始活度浓度往往未知,210Po活度浓度较难推算到采样初始时刻的量值。本文从理论上分析了210Bi对210Po测量结果推算影响大小。大多实际情况空气中210Po/210Pb比小于1,需要考虑空气中210Bi/210Pb的比值,需在一个月内对210Bi进行快速测量,否则无法衡量采样时刻210Bi/210Pb的大小。建议在初始空气中210Bi的活度浓度值未知的情况下,采取短时间采样、快速测量等措施以避免这种误差。

210Pb and 210Po in aerosol are in disequilibrium and separated by the short-lived radionuclide 210Bi.The initial activity concentration of210Bi is often unknown,and the 210Po activity concentration in aerosol is difficult to be estimated to the initial sampling time. This article analyzes the effect of the short-lived radionuclide 210Bi upon the calculation of activity concentration of 210Po. In most of the actual conditions,the activity concentration ratios of 210Po/210Pb in air are less 1,and the ratio of 210Bi/210Pb in air should be considered and 210Bi needs to be measured quickly within one month. Otherwise,210Bi/210Pb cannot be measured. It is recommended to take short-time sampling,rapid measurement and other measures to avoid such errors when the activity concentration of 210Bi in the initial air is unknown.