The intellectual merit of experimental neutrino-less double beta decay efforts has been greatly enhanced by the observation of the oscillations of atmospheric neutrinos, the confirmation of oscillations of solar neutrinos by SuperKamiokande, the demonstration by the SNO experiment that the flux of 8-B neutrinos predicted by Bahcall is correct, and by the recent confirmation of the large Mikheyev-Smirnov-Wolfenstein mixing angle solution of the solar-neutrino problem by the KamLAND experiment. However, these neutrino oscillation data cannot yield the mass scale of neutrinos, nor can they be used to determine that neutrinos are Majorana particles. If the mass of the electron neutrino is ¡Ü 0.2 eV, and neutrinos are Majorana particles, neutrino-less double beta decay is the only hope of determining the mass scale and it is the only practical experiment for determining that they are Majorana particles. Knowledge of the mass would determine what role, if any, neutrinos play as Hot Dark Matter candidates, and if they are Majorana particles, this opens the door to leptogenesis as a possible mechanism for the tiny particle over anti-particle asymmetry in the early universe that would have led to the particle dominated universe observed today.
Hence, CUORE (Cryogenic Underground Observatory for Rare Events), as a neutrino-less double beta decay experiment, has significant discovery potential. This proposal is a request to support the University of South Carolina (USC) in: 1) the first phase of the construction of the 130-Te CUORE experiment; the USC group proposes to take responsibility for the production of the electronic components necessary to instrument the 988 TeO2 bolometers; and 2) an R&D program to determine the technical feasibility and cost of constructing CUORE with Te enriched to 85% in 130-Te.
The broader impacts of this project relate to development of ultralow background Ge detectors, transferred now to commercial companies. The low background technology has been used to produce an ultra low background Ge detector for the Savannah River Low-Background Counting Facility. This facility is used for US government work related to Homeland Defense and National Defense.
