SAPPY: A New Software Pipeline for Analysis of Gamma-Ray
Spectra Produced by Microcalorimeter and High-Purity
Germanium Detectors

Year
2023
Author(s)
D.T. Becker - University of Colorado, Boulder, CO, USA
D.A. Bennett - National Institute of Standards and Technology, Boulder, CO, USA
M.H. Carpenter - Los Alamos National Laboratory, Los Alamos, NM, USA
M.P. Croce - Los Alamos National Laboratory, Los Alamos, NM, USA
M.W. Keller - National Institute of Standards and Technology
K.E. Koehler - Los Alamos National Laboratory
D.G. McNeel - Los Alamos National Laboratory
D.J. Mercer - Los Alamos National Laboratory, Los Alamos, NM, USA
K.A. Schreiber - Los Alamos National Laboratory
D.R. Schmidt - National Institute of Standards and Technology, Boulder, CO, USA
E.S. Teti - Los Alamos National Laboratory, Los Alamos, NM, USA
J.N. Ullom - University of Colorado, Boulder, CO, USA
D. T. Vo - Los Alamos National Laboratory
A.L. Wessels - University of Colorado, Boulder, CO, USA
File Attachment
Abstract
Gamma-ray spectroscopy using cryogenic microcalorimeters has matured significantly in the last few years with the deployment of spectrometers at Los Alamos National Laboratory, Oak Ridge National Laboratory, and Idaho National Laboratory, with additional instruments planned for delivery over the next few years. The goal of these spectrometers is to take advantage of the excellent energy resolution provided by TES microcalorimeters to close the gap in accuracy between non-destructive and destructive assay, with applications in nuclear materials control and accounting. A critical part of these efforts has been in the data processing pipeline. We have developed SAPPY (the Spectral Analysis Program in Python) to extract isotopic information from gamma-ray spectra produced by both microcalorimeter arrays and High-Purity Germanium (HPGe) detectors. SAPPY analyzes microcalorimeter and HPGe spectra using a common code base, using common fundamental nuclear data and consistent algorithms for peak fitting, efficiency curve fitting, and extraction of isotopic contents. The software also directly incorporates uncertainties in nuclear data such as gamma-ray emission probabilities in a consistent way. Using consistent nuclear data and algorithms for both microcalorimeters and HPGe allow direct comparisons of the accuracy of these technologies for performing isotopic analysis.