Speaker
Dr
Nicolas Abgrall
(Lawrence Berkeley National Laboratory (LBNL))
Description
The Majorana Demonstrator will search for the neutrinoless double beta decay (ββ0ν) of the isotope 76Ge with a mixed array of enriched and natural germanium detectors. In view of the next generation of tonne-scale germanium-based ββ0ν-decay searches that will probe the neutrino mass scale in the inverted-hierarchy region, a major goal of the Majorana Demonstrator is to demonstrate a path forward to achieving a background rate at or below 1 cnt/(ROI-t-y) in the 4 keV region of interest (ROI) around the 2039-keV Q-value of the 76Ge ββ0ν-decay. Such a requirement on the background level in conjunction with the best possible energy resolution to increase the signal-to-noise ratio in the ROI significantly constrain the readout electronics. We present here the low background low noise front-end electronics developed for the low-capacitance P-type point-contact (PPC) germanium detectors of the Majorana Demonstrator. This resistive-feedback front-end, specifically designed to have low mass, is fabricated on a radioactivity-assayed fused silica substrate where the feedback resistor consists of a sputtered thin film of high purity amorphous germanium and the feedback capacitor is based on the stray capacitance between circuit Au traces.
Primary author
Dr
Nicolas Abgrall
(Lawrence Berkeley National Laboratory (LBNL))
