Cryogenic Heat–Light Detection System for 1-cm³ Scintillating Crystals

Abstract

We have developed a cryogenic heat and light detection system to investigate phonon and scintillation properties of scintillating crystals for rare event search experiments. The detector setup is designed to utilize a $1 \times 1\times 1$ cm3 scintillating crystal as a target material. A $1.5\times 1.5\times 0.05$ cm3 Ge wafer is used as the absorber of the light detection. Metallic magnetic calorimeters are employed to measure heat and scintillation-light signals of the scintillating crystal, simultaneously, at millikelvin temperatures. This measurement setup is motivated to characterize various types of scintillation crystals in a standard coupon size for a final selection of the crystal compounds to be used for a rare event search experiment. We present the first measurement for a calcium molybdate crystal doped with niobium in the test setup of heat–light detection. Clear particle identification was obtained in comparison of relative amplitude ratios of the phonon and scintillation signals. Moreover, alpha- and electron-induced events showed difference in their pulse shapes of phonon and scintillation signals. We discuss the usage of this setup for the AMoRE $0\nu \beta \beta $ search experiment.