Speaker
Description
The MAJORANA DEMONSTRATOR (MJD) is a low-background experiment that searched for neutrinoless double-beta decay ($0\nu\beta\beta$) in high-purity germanium (HPGe) detectors enriched to $>$90% in $^{76}$Ge. In addition to the search for $0\nu\beta\beta$, MJD's low-background configuration makes it sensitive to several other beyond standard model (BSM) phenomena, including quantum mechanical wavefunction collapse, baryon decay, and bosonic dark matter. While MJD primarily utilized P-type Point Contact (PPC) detectors, a novel detector geometry was developed to increase the active mass while maintaining low noise levels in future experiments. Four Inverted Coaxial Point Contact (ICPC) detectors, each with two to five times greater mass compared to previous geometries, were deployed in MJD for about six months of data collection. This represents the lowest-energy-threshold, in-vacuum dataset available for the new detector geometry. MJD has now concluded data taking and the successor experiment, LEGEND-200, is searching for $0\nu\beta\beta$, primarily with ICPC detectors. To extend the low-energy BSM capabilities of MJD to LEGEND-200 and eventually LEGEND-1000, it is necessary to characterize and understand the behavior of ICPC detectors at low energies ($<$100 keV). This poster will describe the results of this study as well as future prospects and expected challenges.
This material is supported by the U.S. DOE, Office of Science, Office of Nuclear Physics, the NSF Particle Astrophysics and Nuclear Physics Programs, and the Sanford Underground Research Facility.