Investigating Charge Trapping Effects in Germanium Detectors: Mechanical Design Upgrades to the GRITTS Test Stand*

If neutrinos are their own antiparticle (Majorana particles), it could reveal new physics beyond the Standard Model and shed light on the matter-antimatter imbalance in the universe. The Large Enriched Germanium Experiment for Neutrinoless Double Beta Decay (LEGEND) employs high-purity germanium detectors enriched in Ge-76 to search for the posited rare process of neutrinoless double beta decay, the discovery of which will demonstrate that neutrinos are Majorana. Larger mass detectors have reduced surface- and instrumentation-related backgrounds, leading to more sensitive experiments. However, bigger detectors come with their own set of obstacles to overcome, including charge trapping due to impurities in the germanium. The Germanium Resolution due to Impurity Trapping at Temperature System (GRITTS), a cryogenic vacuum test stand at Los Alamos National Laboratory, has been designed to study the effects of these impurities. After the initial testing phase, several improvements to the system were identified to ensure consistent and repeatable data taking. This talk gives an overview on the mechanical design upgrades that enhance experiment ergonomics, reduce the thermal heat load, and accommodate different detector sizes.