Superconducting Bolometer for Neutrino Research

One of the high priority areas of nuclear physics research is to further elucidate the properties of the neutrino. Presently, the absolute neutrino mass scale remains of the most elusive yet unanswered questions regarding the fundamental properties of neutrinos. Radiation Monitoring Devices, Inc. (RMD), in collaboration with Massachusetts Institute of Technology (MIT), has recently begun to develop processes to purify and grow high purity single crystals. In the proposed research, we will develop a superconducting bolometric detector based this research to produce ultra-high purity indium single crystals. This effort should lead to sensitive superconducting detectors that can be used to make measurements of neutrino properties. In this effort, we will investigate metallic super-conducting bolometers made of indium single crystals designed for detecting very low energy events. These detectors, when operated at temperatures of 10-20 mK, reduce sensitivity to background electromagnetic radiation (X-rays, gammas) while achieving high sensitivity. The proposed research will be a rigorous investigation of the purification and crystal growth of indium single crystals and to characterize the purity and detection properties of the crystals produced. RMD will also develop contact deposition methods for fabricating contact structures that will enable discrimination between the quasiparticles and phonons. Bolometer detectors will be built with the necessary size, and tested at low temperatures by our collaborators at MIT. The development of the next generation of advanced detectors will enable future experiments that lead to major breakthroughs in science that is being carried out worldwide. Our efforts will place the United States at the leading edge of a new and exciting detector technology. The proposed work would provide a new supply of radio-pure bolometer crystals that would enable new higher sensitivity physics experiments to be designed and performed, advancing the frontier of scientific knowledge. Techniques developed for ultra-pure crystal manufacturing could also be applied to many other materials in all areas of technology where the performance of devices depends on material purity, such as other devices used in scientific research, optical components, non-destructive testing, and homeland security.