A prototype detector for the CRESST-Ⅲ low-mass dark matter search

摘要

The CRESST-Ⅲ experiment which is dedicated to low-mass dark matter search uses scintillating CaWO_4 crystals operated as cryogenic particle detectors. Background discrimination is achieved by exploiting the scintillating light signal of CaWO_4 and by a novel active detector holder presented in this paper. In a test setup above ground, a nuclear-recoil energy threshold of E_(th) = (190.6 ± 5.2)eV is reached with a 24 g prototype detector, which corresponds to an estimated threshold of ~50 eV when being operated in the low-noise CRESST cryostat. This is the lowest threshold reported for direct dark matter searches. For CRESST-Ⅲ phase 1, ten such detector modules were installed in the cryostat which have the potential to improve significantly the sensitivity to scatterings of dark matter particles with masses down to ~ 0.1 GeV/c~2.