Year
2019
Abstract
Microcalorimeter technology has now advanced to the point where we are building instruments designed for routine measurements in typical analytical laboratories. We will describe a compact yet capable ultra-high-resolution microcalorimeter gamma spectrometer being built for field testing and present recent results. Through the use of large detector arrays with hundreds of individual elements, high-bandwidth multiplexed readout, optimized cryogenic systems, and automated data processing, this instrument overcomes many of the practical limitations of previous microcalorimeter systems. With an order of magnitude better energy resolution than semiconductor detectors, the development of microcalorimeters is intended to close the performance gap between non-destructive and destructive analysis methods. Comprehensive measurements of plutonium-containing materials have proven that this improved energy resolution leads to reduced uncertainty and bias in quantitative analysis of plutonium isotopic ratios. Implemented at a reprocessing facility, rapid, nondestructive microcalorimeter gamma spectroscopy measurements could reduce reliance on sampling, mass spectrometry, and destructive chemical analysis. The technology also provides a path to better measurements of nuclear data needed for safeguards such as gamma- and x-ray energies, branching ratios, and half-lives of important nuclides.