【摘要】 研究了各种常见核素α、β放射性在BH-1216低本底α、β测量仪上的计数效率与其射线能量之间的关系,以241Am和40K分别作为总α和总β的标准物质,计算了常见核素的总α和总β放射性计数效率E相对于标准物质计数效率Esd的等效因子ρ(ρ=E/Esd),用于比较已知核素活度浓度样品的总放射性估算值与测量值间的一致性。研究还发现,放射性活度与计数率的比值,即活度-计数率比K,与待测放射源的质量厚度之间存在良好的线性关系。用活度-计数率比代替计数效率作"效率校正",计算方便、精度较高。基于上述研究建立了适用于食品和环境样品中总α和总β放射性的测定方法。更多还原

【Abstract】 This paper describes a study on the relationship between count efficiency and energy of such common nuclides as having α or β radioactivity on the BH-1216 low background measuring meters.With 241Am and 40K as references,the equivilant factor ρ(ρ=E/Esd) was calculated to evaluate the consistency of estimates with measured values of total radioactivity of known nuclide concentrations.The study gives a good liner relationship between activity-to-count ratio K and mass-thickness of radioactive source to be measured.It is convenient for radioactivity-to-count ratio to be used to calibrate count efficiency,with high precision.Thus,a measurement method of total α and total β is established.更多还原