This paper presents the non-destructive assay of two AmLi sources used for detector characterization and active interrogation at PNNL, identified as MRC-101 and MRC-103. First, a detailed description of the internal configuration of 2724-BT encapsulated MRC sources is established. X-ray radiographs of the AmLi sources are reported for the first time to verify the dimensions and orientation of the encapsulation. Notably, a density variation was observed as a contrast change across the height of the source cavities. Contrary to commonly made assumptions in literature, it is indirectly observed that the AmLi source/target material only occupies a portion of the source cavity. The intensity of the prompt gamma-rays resulting from the inelastic scatter of alpha particles on ⁷Li was used to calculate the mass ratios of LiH:AmO₂. The gamma-ray spectra revealed the presence of numerous impurities in both source and target material (²⁴³Am, ²³⁷Np, ¹⁵⁴Eu, ²³Na, and ⁹Be). Neutron-gamma production ratios were applied to the intensity of the Doppler-broadened peaks from alpha-induced reactions with ⁷Li, ⁹Be, and ²³Na to calculate neutron rates for both sources. A neutron/alpha production yield (derived in this work) was then related to the atomic concentration of these isotopes to find the approximate masses within each source. Ultimately, the AmLi source density was estimated with prompt gamma analysis based on partial source volumes as $0.45\pm 0.08{\mathrm{g∕cm}}^3$.

本文介绍了用于PNNL探测器特征和主动询问的两种AmLi信号源的无损检测，分别为MRC-101和MRC-103。首先，建立了对2724-BT封装的MRC源的内部配置的详细描述。首次报告了AmLi源的X射线照片，以验证封装的尺寸和方向。值得注意的是，在整个源腔的高度上观察到作为对比度变化的密度变化。与文献中通常的假设相反，间接观察到AmLi源/目标材料仅占据源腔的一部分。α粒子在⁷上的非弹性散射导致的即时伽马射线强度使用Li来计算LiH：AmO ₂的质量比。伽马射线光谱揭示了源材料和目标材料中都存在大量杂质（²⁴³ Am，²³⁷ Np，¹⁵⁴ Eu，²³ Na和⁹ Be）。将中子伽马产生比应用于⁷ Li，⁹ Be和^23的α诱导反应产生的多普勒增宽峰的强度Na来计算两种来源的中子速率。然后将中子/α的产量（此工作中得出）与这些同位素的原子浓度相关联，以找到每个源中的近似质量。最终，根据部分源体积，通过快速伽马分析估算了AmLi源密度$0。45\pm 0。08{\mathrm{克·厘米}}^3$。