发表机构
University of Michigan; Sandia National Laboratories（密歇根大学; 桑迪亚国家实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究针对中子源识别难题，提出基于散射光谱测量的可扩展贝叶斯框架，引入BEAP算法，经实验和模拟验证，该算法能有效识别单源和多源混合物，是核安全和应急响应中实用、可扩展且稳健的工具。
AI 中文摘要
可靠的中子源识别对核不扩散、保障措施和国土安全至关重要，但由于中子光谱反演往往病态，尤其在混合源场中具有重叠光谱特征时，仍然具有挑战性。在此，我们提出了一个可扩展的贝叶斯框架，用于从反冲光谱测量中识别中子源，采用基于证据的模型选择。该方法引入了贝叶斯证据自适应追踪（BEAP）算法，通过根据贝叶斯证据对候选源集合的组合空间进行迭代排序、保留和修剪源混合物来有效搜索。我们通过受控的Cf-252和氘 - 氘中子发生器测量实验验证了该框架，并辅以涵盖具有不同发射率和混合复杂性的代表性裂变、（α，n）和聚变源的高保真蒙特卡罗模拟。BEAP能在决定性统计支持（>4σ）下正确识别单源和多源混合物，根据源混合物复杂性、光谱相似性和发射率不平衡，需要\(\mathcal{O}(10^1)\)到\(\mathcal{O}(10^6)\)次检测到的反冲事件。这些发现确立了BEAP作为混合中子场中定量源识别的实用、可扩展且稳健的工具，显著扩展了基于散射的中子光谱仪在核安全和应急响应应用中的操作能力。
英文摘要
Identifying neutron-emitting materials is central to nuclear nonproliferation, safeguards, nuclear forensics, and emergency response, yet remains difficult when several sources contribute simultaneously: relevant fission, $(α,\text{n})$, and fusion sources emit broad, strongly overlapping energy distributions, and the associated spectral inversion is severely ill-conditioned. Here we demonstrate quantitative identification of mixed neutron fields directly from scatter-based (recoil) spectroscopy measurements, together with simultaneous estimation of the emission rate of each contributing source and a rigorous statistical confidence level for every candidate source combination. Using a compact $21.6\,\mathrm{cm}^3$ organic-glass scintillator spectrometer, we correctly identify Cf-252, a deuterium--deuterium (DD) neutron generator, and their mixture with decisive statistical support ($>\!4σ$), and further resolve a weak deuterium--tritium contaminant in the nominal DD generator field. High-fidelity Monte Carlo simulations spanning exhaustive single-, two-, and three-source mixtures show that identification requires remarkably little information: between $\mathcal{O}(10^1)$ and $\mathcal{O}(10^6)$ detected recoil events, set primarily by spectral similarity, mixture complexity, and emission-rate imbalance. For the compact spectrometer used here, this corresponds to acquisition times as short as a few minutes. These results substantially extend the operational reach of simple single-volume neutron spectrometers, enabling rapid, quantitative, and confidence-calibrated attribution of complex neutron fields in field-deployable instruments.
Comments16 pages, 6 figures, 1 ancillary file
