Thermal pathways in ultra-high resolution gamma-ray detector materials for nuclear material detection [10U08UDzink]

特殊核材料的非法贩运和生产是全球最关切的问题。目前，闪烁探测器用于确定边境口岸入境车辆或货物中是否存在SNM。这些探测器具有成本效益和快速，但具有相对较差的光谱能量分辨率。因此，它们无法将高浓缩铀（HEU）等危险物质与普通和无害的背景辐射区分开来。即使是高纯度的锗探测器，目前最先进的伽马射线探测技术，通常也没有足够好的分辨率来清楚地将高浓铀辐射从背景中分离出来。低温微热量计是一种新型的探测器，它提供的分辨率能够将这些线从任何干扰中分离出来。该项目的总体目标是提供必要的知识，使这些微热量计成为一种高效和现场可用的仪器，有助于解决现实世界的核安全和法医问题。具体来说，我们将设计和实施这些低温探测器的热特性测量，这将使更快，更高效，具有极高光谱分辨率的阵列兼容传感器成为可能。这些实验将由一个团队设计和实施，该团队包括博士后学者，研究生和本科生研究人员，他们还将与国家标准与技术研究所和洛斯阿拉莫斯国家实验室的科学家合作。该项目更广泛的影响包括研究生、研究生和本科生的教育和技术培训，并加强丹佛大学、NIST和LANL之间的伙伴关系。此外，我们的大部分工作都集中在开发和实施新的测量技术，以探测探测器及其微机械组成材料的热性能。这些新技术中的许多将对未来的广泛实验有用，并且它们的发展为学生提供了学习与高科技行业相关的技术的机会，例如硅微加工和电路设计与表征。

The illicit trafficking and production of special nuclear materials (SNM) is a paramount global concern. Currently, scintillator detectors are used to determine whether SNM are present in incoming vehicles or cargo at border crossings. These detectors are cost effective and fast, but have a relatively poor spectral energy resolution. As a result, they cannot discriminate dangerous materials such as highly-enriched uranium (HEU) from common and innocuous background radiation. Even high purity germanium detectors, the current state of the art for gamma-ray detection, often do not have good enough resolution to clearly separate HEU emissions from background. Cryogenic microcalorimeters are a new class of detectors that provide resolution capable of separating these lines from any interference. The overall goal of this project is to provide the knowledge necessary to make these microcalorimeters an efficient and field usable instrument that will help solve real-world nuclear security and forensics problems. Specifically, we will design and implement measurements on the thermal properties of these low-temperature detectors that will enable faster, more efficient, array-compatible sensors with extremely high spectral resolution. These experiments will be designed and implemented by a team that includes a postdoctoral scholar, graduate and undergraduate student researchers, who will also work collaboratively with scientists at the National Institute of Standards and Technology and Los Alamos National Lab. The broader impacts of the project encompass education and technical training of post-graduate, graduate, and undergraduate students, and strengthening partnerships between the University of Denver, NIST and LANL. In addition, much of our work focuses on development and implementation of novel measurement techniques to probe thermal properties of detectors and their micromachined constituent materials. Many of these new techniques will be useful for a broad range of future experiments, and their development provides opportunities for students to learn techniques relevant to high-tech industry such as silicon micromachining and circuit design and characterization.