Accurate measurements of ²³⁵U enrichment within metallic nuclear fuels are essential for understanding material performance in a neutron irradiation environment, and the origin of secondary phases (e.g. uranium carbides). In this work, we analyse ²³⁵U enrichment in matrix and carbide phases in low enriched uranium alloyed with 10 wt% Mo via two chemical imaging modalities—nanoscale secondary ion mass spectrometry (NanoSIMS) and atom probe tomography (APT). Results from NanoSIMS and APT are compared to understand accuracy and utility of both approaches across length scales. NanoSIMS and APT provide consistent results, with no statistically significant difference between nominal enrichment (19.95 ± 0.14 at% ²³⁵U) and that measured for metal matrix and carbide inclusions.

中文翻译：

---

金属核燃料中铀富集的纳米级二次离子质谱分析和原子探针层析成像分析

对金属核燃料中²³⁵ U富集的准确测量对于了解中子辐照环境中的材料性能以及次级相（例如碳化铀）的起源至关重要。在这项工作中，我们通过两种化学成像方法-纳米级二次离子质谱（NanoSIMS）和原子探针层析成像（APT），分析了含10 wt％Mo的低浓缩铀中基质和碳化物相的²³⁵ U富集。比较NanoSIMS和APT的结果，以了解两种方法在长度范围内的准确性和实用性。NanoSIMS和APT提供一致的结果，标称富集之间无统计学差异（19.95±0.14 at％^235）U）以及针对金属基体和碳化物夹杂物测得的值。