January 2024

Journal

Energy calibration of germanium detectors for the Majorana Demonstrator

By:
Arnquist, I.; Avignone, F.T. III; Barabash, A.S.; Barton, C; Bhimani, K.H.; Blalock, E; Bos, B; Busch, Matthew ; Buuck, M.; Caldwell, T; Chan, Y-D; Christofferson, Cabot-Ann D; Chu, P.-H.; Clark, M. L.; Cuesta, C.; Detwiler, Jason A; Efremenko, Yuri V; Ejiri, H.; Elliott, Steven R; Giovanetti, G.; Green, Matthew P; Gruszko, Julieta Y; Guinn, Ian S; Guiseppe, Vincente E; Haufe, C; Henning, R.; Aguilar, Dylan C; Hoppe, E.W.; Hostiuc, A; Kidd, M.; Kim, I; Kouzes, R.; Lannen, Thomas; Li, A; Lopez Castano, Jose M; Martin, Eric; Martin, R; Massarczyk, Ralph J; Meijer, S; Oli, T; Paudel, L; Pettus, Walter C; Poon, A.W.P.; Radford, David C; Reine, A; Rielage, K.; Ruof, N; Schaper, Danielle; Tedeschi, D; Varner Jr, Robert L; Vasilyev, S.; Wilkerson, John F; Wiseman, C; Xu, W; Yu, Chang-Hong ; Zhu, B. X.
Journal Name:
Journal of Instrumentation
Volume:
18
Issue Number:
09
Publication Date:
January 16, 2024
View DOI Listing:
https://doi.org/10.1088/1748-0221/18/09/P09023

Abstract

The Majorana Demonstrator was a search for neutrinoless double-beta decay (0νββ) in the 76Ge isotope. It was staged at the 4850-foot level of the Sanford Underground Research Facility (SURF) in Lead, SD. The experiment consisted of 58 germanium detectors housed in a low background shield and was calibrated once per week by deploying a 228Th line source for 1 to 2 hours. The energy scale calibration determination for the detector array was automated using custom analysis tools. We describe the offline procedure for calibration of the Demonstrator germanium detectors, including the simultaneous fitting of multiple spectral peaks, estimation of energy scale uncertainties, and the automation of the calibration procedure.