Production and Decay of the Ge73-m Metastable State in a Low-Background Germanium Detector
Abstract
The 73m metastable states decay with a very characteristic signature which allow them to be tagged event-by-event. Studies were performed using data taken with a high-purity germanium detector in a low-background laboratory near a nuclear power reactor core where -flux was 6.4 × 1012 ~ cm-2 s-1. The measured average and equilibrium production rates of 73m were (8.7 0.4) and (6.7 0.3) ~ kg-1 day-1, respectively. The production channels were studied and identified. By studying the difference in the production of 73m between the reactor ON and OFF spectra, the limiting sensitivities at the range of 10-42 - 10-43 ~ cm2 for the cross-sections of neutrino-induced nuclear transitions were derived. The dominant background are due to β-decays of cosmic-ray induced 73Ga. The prospects of enhancing the sensitivities at underground locations are discussed.