DUSEL R&D: Development of Bolometric Detectors for Neutrinoless Double Beta Decay and Neutrino Mass Experiments

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

This proposal addresses two fundamental questions in neutrino physics: Are neutrinos Majorana or Dirac particles, and what is the absolute neutrino mass? The only practical experimental technique currently available to address the first question is to search for neutrinoless double beta decay; the second can be answered by measuring the distortion near the endpoint of a single beta decay energy spectrum. A limited number of technologies are available to investigate these questions and cryogenic bolometers is the only detection method that may offer answers to both. The proposed research will investigate ways to improve on the sensitivity levels achievable with current bolometers for neutrino experiments. Specifically, we will pursue studies to understand and discriminate sources of radioactive backgrounds by making use of multiple signal characteristics available from bolometers such as heat and scintillation. In addition, R&D on the signal extraction from bolometers will be carried out to improve the detector speed. The readout and scalability of microcalorimeters is crucial for the next generation of direct neutrino mass measurement using bolometers. Cryogenic bolometers are being used extensively in astronomy and astrophysics research. They have also found application in a few neutrino experiments (double beta decay and single beta decay endpoint mass measurements), but the expertise currently resides mostly in Europe. The research proposed here will help develop the expertise of this promising technology in the neutrino community so that we are ready to pursue sensitive neutrino mass and/or double beta decay experiments using bolometers when DUSEL becomes available.