2014/10/31 by R. Strauss, G. Angloher, A. Bento +41
Physics and Astronomy · #Background radiation #Cosmology #Dark Matter and Cosmic Phenomena #Dark matter #Neutrino Physics Research #Phase (matter) #Radiation #Radiation Detection and Scintillator Technologies #Scattering #Sensitivity (control systems) #WIMP #Weakly interacting massive particles #physics.ins-det
paper · pdf · doi:10.1088/1475-7516/2015/06/030
published as JCAP 1506 (2015) 030 · 17 pages, 7 figures, 3 tables
openalex publication_date 2015/06/16 · arxiv created 2016/01/25 · arxiv updated 2016/01/26 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/08
The experiment CRESST-II aims at the detection of dark matter with scintillating CaWO 4 crystals operated as cryogenic detectors. Recent results on spin-independent WIMP-nucleon scattering from the CRESST-II Phase 2 allowed to probe a new region of parameter space for WIMP masses below 3 GeV/c 2 . This sensitivity was achieved after background levels were reduced significantly. We present extensive background studies of a CaWO 4 crystal, called TUM40, grown at the Technische Universität München. The average beta/gamma rate of 3.51/[kg keV day] (1-40 keV) and the total intrinsic alpha activity from natural decay chains of 3.08±0.04 mBq/kg are the lowest reported for CaWO 4 detectors. Contributions from cosmogenic activation, surface-alpha decays, external radiation and intrinsic alpha/beta emitters are investigated in detail. A Monte-Carlo based background decomposition allows to identify the origin of the majority of beta/gamma events in the energy region relevant for dark matter search.