Assessing the capabilities of cryogenic microcalorimeter detectors for the analysis of plutonium isotopic content

Year
2011
Author(s)
Pete Karpius - Los Alamos National Laboratory
D. T. Vo - Los Alamos National Laboratory
A.S. Hoover - Los Alamos National Laboratory
M. W. Rabin - Los Alamos National Laboratory
D. A. Bennett - National Institute of Standards and Technology, Boulder, CO
R. D. Horansky - National Institute of Standards and Technology, Boulder, CO
V. Kotsubo - National Institute of Standards and Technology, Boulder, CO
J. N. Ullom - National Institute of Standards and Technology, Boulder, CO
D. W. Lee - Los Alamos National Laboratory
N. Hoteling - Los Alamos National Laboratory
Abstract
The results of a recent measurement campaign designed to study the capabilities of gamma-ray microcalorimeters for the analysis of plutonium isotopic content is described. Three standard plutonium sources with varying isotopic content were measured for ~250 hours each with both HPGe and microcalorimeter detectors and analyzed incrementally with FRAM in order to study the scaling of error bars as a function of peak area. Since FRAM computes error bars from peak areas and the e?ciency curve, this study was limited to the assessment of statistical uncertainty only. Thus, an improvement in the statistical error of ~30% was observed for each source, which can be attributed to the improvement in peak-to-background ratio commensurate with the improvement in FWHM exhibited by the microcalorimeter system. A more complete analysis of the error bars is needed before one can truly establish the degree of improvement and, further, the lower limit to the error bar achievable with microcalorimeters