The GeMSE Low-Background Facility for Meteorite and Material Screening

Low-background gamma-ray spectrometry is a widely used method in different scientific disciplines. It serves for, e.g., the assessment of the radiopurity of materials for rare event search experiments, while in the field of Geology it is crucial to characterize meteorite samples. GeMSE (Germanium Material and meteorite Screening Experiment) is an interdisciplinary project addressing both of these topics. Using a p-type high-purity germanium (HPGe) detector installed in the Vue-des-Alpes underground laboratory ($\sim$ 620 m.w.e. depth), the GeMSE facility features several layers of shielding, a permanent N${}_2$-flushing in a closed glove-box and an active muon veto. As a result, the background levels are highly competitive: < 240 counts/day in the 100 - 2700 keV energy range. GeMSE is ideally suited for the ongoing material selection campaign for the upcoming XENONnT dark matter detector. This talk will describe the facility, the calibration methods and the data analysis, and will present some results of recently measured samples.