A Low-noise Germanium Ionization Spectrometer for Low-background Science

Abstract

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 Co-60 gamma ray.