<EM>k</EM><SUB>0</SUB>-NAA样品测量架位自动调节和半参量化效率计算

k₀-NAA样品测量架位自动调节和半参量化效率计算

摘要: 设计了中子活化自动换样和架位精密调节系统。实现了任意衰变纲图的γ发射核在源探测器为 0～280 mm 范围内不同测量位置的效率测定，提出了解决k₀法不同测量几何的效率归一以及级联符合校正的半参量化方法。对于源与探测器距离较远的位置（符合效应可忽略），采用有效作用深度进行效率计算；对于源与探测器距离较近的位置（符合效应不能忽略），采用实验测得不同位置的效率比进行计算。

Abstract: An automatic sample changer and an accurate sample positioning system were developed for γ-spectrum measurements in general and k₀-NAA in particular. Full energy peak efficiencies for radionuclides with arbitrary decay schemes were calibrated over 0-280 mm source-detector distances. A semi-parametric method was established for efficiency normalizations among different counting positions-parametric effective interactive depth method for efficiency normalizations of “far” (true coincidence effect negligible) counting positions, and experimentally determined “rack-ratio” of a given γ-ray from a given nuclide for that of “near” (true coincidence effect worth considering) counting positions.