Simultaneous measurement of phonons and scintillation light for active background rejection in the CRESST experiment

Abstract

We report on simultaneous detection of phonons and scintillation light using a cryogenic calorimeter composed of a scintillating CaWO 4 crystal and a separate light detector, both instrumented with a tungsten superconducting phase transition thermometer operating at about 12 mK. Clear discrimination between electron and nuclear recoils was demonstrated by irradiating the detector with electrons, photons and neutrons. The shape of the nuclear recoil energy spectrum induced by the neutrons could be well reproduced by simulations.