土壤样品总β放射性测量的计数效率校正研究

The study of correction of counting efficiency in measurement of global-β radioactivity in soil samples

采用不同形态的 KCl、U、Th和 Ra标准源作甄别阈 -计数效率曲线 ,以校正用 KCl作标准源计算计数效率所引起的测量误差。实验结果表明 ,土壤样品总 β测量的标准样品在选择矿粉样或加标准溶液样时 ,所得计数效率相同 ;用 KCl作标准源刻度环境土壤样品的总 β计数效率 ,其效率校正因子 K值为 0 .

This paper uses different forms of standard sources of KCl、U、Th and Ra to constisuct the discriminating threshold counting efficiency curve, in order to correct the measurement error caused by using KCl as the standard source to calculate counting efficiency.The experiment result indicates that the mine powder is more feasible than the standard solution in measurement of global β in soil sample. The correction factor K is 0.77, when KCl is used as standard source to calibrate the global β counting efficiency of environmental soil samples.