Neodymium-Containing Single Crystals for Neutrinoless Double Beta Decay Detection

The Neutrinoless Double Beta Decay Underground Detector has been identified by DOE as a high scientific priority. Unfortunately, the current generation of proposed experiments to determine neutrino mass would require 500 kg of germanium (Ge) that is isotopically enriched to 86% in 76Ge. The cost of this specialized Ge would exceed $100 million. 150Nd is an alternate parent isotope for neutrinoless double beta decay, which could substantially reduce the size and cost of cooling and detection infrastructure. However, the favorable theoretical decay rate of 150Nd can only be exploited by using a detector with high detection efficiency and excellent energy resolution. The only known approach for constructing such a detector is to construct a bolometer of a single crystal from a compound that contains a significant fraction of neodymium. Therefore, this project will develop technology for growing bulk crystals of a high-purity, single-crystal neodymium-containing oxide optimized for bolometer applications. Commercial Applications and other Benefits as described by the awardee: The primary application of single crystal neodymium-containing oxides will be for cryogenic bolometers for neutrinoless double beta decay. The value of the scientific goal of determining neutrino mass is inestimable. In addition, neodymium gallate may have application as a substrate for high temperature superconductors.