A Cryogenic Detector Characterization Facility in the Shallow Underground Laboratory at the Technical University of Munich

摘要

The Physics Department of the Technical University of Munich operates a shallow underground detector laboratory in Garching, Germany. It provides $$sim 160,{mathrm{m}^2}$$ ～ 160 m 2 of laboratory space which is shielded from cosmic radiation by $$sim 6,mathrm{m}$$ ～ 6 m of gravel and soil, corresponding to a shielding of $$sim 15,{mathrm{m.w.e.}}$$ ～ 15 m . w . e . . The laboratory also houses a cleanroom equipped with work- and wetbenches, a chemical fumehood as well as a spin-coater and a mask-aligner for photolithographic processing of semiconductor detectors. Furthermore, the shallow underground laboratory runs two high-purity germanium detector screening stations, a liquid argon cryostat and a $$^3$$ 3 He– $$^4$$ 4 He dilution refrigerator with a base temperature of $$le 12-14,mathrm{mK}$$ ≤ 12 - 14 mK . The infrastructure provided by the shallow laboratory is particularly relevant for the characterization of $$hbox {CaWO}_4$$ CaWO 4 target crystals for the CRESST-III experiment, detector fabrication and assembly for rare event searches. Future applications of the laboratory include detector development in the framework of coherent neutrino nucleus scattering experiments ( $$u $$ ν -cleus) and studying its potential as a site to search for MeV-scale dark matter with gram-scale cryogenic detectors.