Development of Low Temperature Detector with CaMoO4 Crystal for Neutrinoless Double Beta Decay

Abstract

Double beta decay is one of the rarest nuclear decay processes. Among its different decay modes, neutrinoless mode occurs only when neutrinos are massive Majorana particles. Hence its detection will prove neutrinos to be Majorana particles as well as provide effective neutrino mass from its measured decay rate. CaMoO4 crystal has been developed by KIMS collaboration for this purpose. Mo-100 in the crystal is a candidate for neutrinoless double beta decay. As a preliminary research, we tested a small piece of the crystal (~1cm^3) as an absorber of a low temperature detector. The crystal was irradiated with alpha particles from Am-241. In this report, feasibility of the crystal will be discussed on the basis of measured energy resolution.