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

University Of Denver, Denver CO

Investigators

Abstract

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.