Characterization of High-Purity Germanium Detectors with Amorphous Germanium Contacts in Cryogenic Liquids

Abstract

For the first time, planar high-purity germanium detectors with thin amorphous germanium contacts were successfully operated directly in liquid nitrogen and liquid argon in a cryostat at the Max-Planck-Institut für Physics in Munich. The detectors were fabricated at the Lawrence Berkeley National Laboratory and the University of South Dakota, using crystals grown at the University of South Dakota. They survived long-distance transportation and multiple thermal cycles in both cryogenic liquids and showed reasonable leakage currents and spectroscopic performance. Also discussed are the pros and cons of using thin amorphous semiconductor materials as an alternative contact technology in large-scale germanium experiments searching for physics beyond the Standard Model.

Exploring the Potential of Residual Impurities in Germanium Detectors for Low-Mass Dark Matter Detection

“…The University of South Dakota (USD) hosts a distinctive Ge detector production facility, encompassing Ge zone refining [14][15][16] , crystal growth [17][18][19] , crystal characterization 20 , and detector fabrication [21][22][23] . Moreover, USD has pioneered the development of planar Ge detectors [21][22][23] employing locally cultivated crystals [17][18][19] . Leveraging this capability, a planar p-type Ge detector, measuring 7 cm × 7 cm × 4 cm, can be manufactured for optimal performance at 5.2 K. This Ge detector boasts a total mass of roughly 1.04 kg.…”

“…The University of South Dakota (USD) hosts a distinctive Ge detector production facility, encompassing Ge zone refining [14][15][16] , crystal growth [17][18][19] , crystal characterization 20 , and detector fabrication [21][22][23] . Moreover, USD has pioneered the development of planar Ge detectors [21][22][23] employing locally cultivated crystals [17][18][19] .…”