Simulations and Testing of a Rapid Surface Characterization Scanner for the LEGEND Experiment (2024)

Undergraduate: Andrew Mattson

Faculty Advisor: Reyco Henning
Department: Physics and Astronomy

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The neutrino has repeatedly defied the otherwise exceptionally accurate predictions of the Standard Model. They have mass, oscillate between flavors, and could violate a conservation law through neutrinoless double beta decay. The LEGEND experiment aims to observe this rare event using a large mass of high-purity germanium ICPC detectors. Much of their behavior has been extensively studied, but surface events remain inadequately characterized. The UNC Surface Scanner is being developed to address this lack of scrutiny. Work was done to bring it to a status where data-taking is possible. The accuracy and efficacy of the device was assessed by simulations of collimated and background sources, and comparing the energy distributions to real data from the scanner. This was done for Americium, Bismuth, Thallium, and Potassium isotopes. The simulations were post-processed and analyzed to extract meaningful physics data, and this was used to quantify the Surface Scanner's performance.