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Recent progress on the development of very low noise high purity germanium ionization spectrometers has produced an instrument of 1.2 kg mass and excellent noise performance. The detector was installed in a low-background cryostat intended for use in a direct detection search for low mass, WIMP dark matter. This transaction reports the thermal characterization of the cryostat, specifications of the newly prepared 1.2 kg p-type point contact germanium detector, and the spectroscopic performance of the integrated system. The integrated detector and low background cryostat achieved full-width-at-half-maximum noise performance of 98 eV for an electronic pulse generator peak and 1.9 keV for the 1332-keV 60Co gamma ray. [ABSTRACT FROM AUTHOR]

This paper presents progress on the development of a cryostat intended to improve upon the low-energy threshold (below 0.5 keV) of p-type point contact germanium gamma-ray spectrometers. Ultra-low energy thresholds are important in the detection of low-energy nuclear recoils, an event class relevant to both dark matter direct detection and measurement of coherent neutrino-nucleus scattering. The cryostat design, including a thermal and electrical-field model, is given. A prototype cryostat has been assembled and data acquired to evaluate its vacuum and thermal performance. [ABSTRACT FROM PUBLISHER]

Historically, large germanium arrays for field applications have consisted of multiple detectors each housed in their own cryostat. In order to ruggedize the detectors for field use these cryostats have had additional support material introduced that significantly impacted cryogenic performance. This paper presents the development of a new cryostat design suitable for deployment of ∼10 kg of high purity germanium detectors that achieves outstanding cryogenic performance (∼5 W at 80 K) while providing the high detection efficiency required for stand-off measurements and the ruggedization required for use in a variety of field applications. [ABSTRACT FROM AUTHOR]

Abstract: A high-purity germanium (HPGe) crystal was operated in liquid argon (LAr) as a Compton-suppressed radiation spectrometer. Spectroscopic quality resolution of less than 1% of the full-width half-maximum of full energy deposition peaks was demonstrated. The construction of the small apparatus used to obtain these results is reported. The design concept is to use the LAr bath to both cool the germanium crystal to operating temperatures and act as a scintillating veto. The scintillation light from the LAr can veto cosmic rays, external primordial radiation, and gamma radiation that does not fully deposit within the germanium crystal. This technique was investigated for its potential impact on ultra-low-background gamma-ray spectroscopy. This work is based on a concept initially developed for future germanium-based neutrinoless double-beta decay experiments. [Copyright &y& Elsevier]