基于多核素的相对效率法

Relative efficiency method based on multi-nuclide

核取证学中材料成分分析、核恐怖事件中裂变产物分析和大样品活化分析等非破坏性测量中,探测效率刻度存在较大的挑战。本文解析了大样品多核素相对效率分析方法的基本原理,建立了基于多元素相对效率拟合方法。并通过某特殊形状铀辐照样品中裂变产物的特征峰信息,进行了双核素(母子体)和三核素(非母子体)效率拟合验证,研究表明多核素自刻度方法校准因子与母子体衰变校正因子在2%误差范围内一致。研究结果为特殊形状辐射样品无损分析技术奠定了基础。

Background： In the non-destructive measurement, including the analysis of material composition of nuclear forensics, fission product analysis of nuclear terrorism event and large sample activation analysis, there is a big challenge for the detection efficiency calibration. Purpose： This paper analyzed the basic principle of the relative efficiency method of radiation samples with multi-nuclide, and established the relative efficiency fitting method for multi-nuclide. Methods： Through the peak information of the fission products from a special irradiated uranium sample, the efficiency fitting of dual-nuclide （parent-daughter nuclides） and three nuclides （no parent-daughter nuclides） was verified. Results： The study showed that the calibration factor of the self-calibration method with multi-nuclide was consistent with the factor of the parent-daughter nuclides＇ decay in the error range of 2%. Conclusion： Results laid the foundation for the non-destructive analysis techniques of the radioactive samples with special shapes.