UNC-CH Physics and Astronomy Thesis Proposal Presentation

Morgan Clark

“Characterization, Commissioning, and First Measurements of LEGEND-200 Detectors”

The Large Enriched Germanium Experiment for Neutrinoless double-beta Decay (LEGEND) is a next-generation experiment searching for neutrinoless double-beta decay in 76Ge. The first phase, LEGEND-200, is currently being built in the existing GERDA cryostat at Laboratori Nazionali del Gran Sasso (LNGS) in Italy and will take its first commissioning data in 2021. LEGEND-200 hopes to achieve a half-life sensitivity for 0nbb of 1027 years. In order to achieve this, LEGEND-200 requires extremely low backgrounds and relies on technologies developed by the GERDA experiment and the MAJORANA DEMONSTRATOR. The experiment will deploy about 200-kg of detectors with 140-kg of new detectors fabricated specifically for LEGEND. The inverted coaxial point contact (ICPC) detector was developed specifically for this experiment to take advantage of the excellent energy resolution and pulse shape discrimination properties of PPC detectors without the limiting mass of the MAJORANA and GERDA style PPC detectors. My thesis work will focus on characterizing many of these detectors being fabricated at ORTEC in Oak Ridge, TN to determine their energy resolution, PSD parameters, depletion voltage, and dead layer. I will also be involved in the installation of the first detectors and the analysis of the first physics result from LEGEND-200.