Internal Scanner for Rapid Characterization of $^{76}$Ge detectors used in LEGEND-200
ORAL
Abstract
The LEGEND collaboration is developing an experimental search for neutrinoless double beta decay ($0\nu\beta\beta$) in the $^{76}$Ge isotope with a discovery potential of a half-life beyond $10^{28}$ years. The first phase, Legend-200, is an experimental search using 200 kg of $^{76}$Ge-enriched germanium, with data taking beginning in 2021. The search for $0\nu\beta\beta$ requires a precise understanding of the behaviour of germanium detectors, necessitating extensive detector characterization. As characterization for Legend-200 is underway, there is an effort at UNC to develop a scanner for the characterization of the $\alpha, \beta,$ and $\gamma$ response on and near the passivated surface of inverted coaxial point-contact detectors (ICPC) to be deployed in the experiment. Scanning a selected sample of points in a low background environment allows for rapid characterization. An $^{241}$Am source provides 5.45 MeV $\alpha$s for measuring the $\alpha$ response on the passivated surface while a $^{137}$Cs source provides 625 keV internal conversion electrons for studying the $\beta$ response. The development and initial results of the internal scanner will be presented.
*This material is based upon work supported by the U.S. NSF, DOE-NP, NERSC and through the LANL LDRD program, the Oak Ridge Leadership Computing Facility; the Russian RFBR, the Canadian NSERC and CFI; the German BMBF, DFG and MPG; the Italian INFN; the Polish NCN and Foundation for Polish Science; and the Swiss SNF; the Sanford Underground Research Facility, and the Laboratori Nazionali del Gran Sasso
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