Energy-dependent light quenching in CaWO ₄ 4 crystals at mK temperatures

2014/01/31 by R. Strauss, G. Angloher, A. Bento +42 · 36 citations
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Dark matter #Detector #Neutron #Particle (ecology) #Particle physics theoretical and experimental studies #Quenching (fluorescence) #Radiation Detection and Scintillator Technologies #WIMP #astro-ph.CO #astro-ph.IM #physics.ins-det

paper · pdf · doi:10.1140/epjc/s10052-014-2957-5

published in The European Physical Journal C 74(7) (Springer Science+Business Media) · 6 pages, 6 figures, 2 tables

openalex publication_date 2014/07/01 · arxiv created 2016/01/25 · arxiv updated 2016/01/26 · openalex created_date 2017/03/16 · openalex updated_date 2026/08/05

Abstract

Scintillating CaWO ₄ 4 single crystals are a promising multi-element target for rare-event searches and are currently used in the direct dark matter experiment CRESST (Cryogenic Rare Event Search with Superconducting Thermometers). The relative light output of different particle interactions in CaWO ₄ 4 is quantified by quenching factors (QFs). These are essential for an active background discrimination and the identification of a possible signal induced by weakly interacting massive particles (WIMPs). We present the first precise measurements of the QFs of O, Ca and W at mK temperatures by irradiating a cryogenic detector with a fast neutron beam. A clear energy dependence of the QF of O and, less pronounced, of Ca was observed for the first time. Furthermore, in CRESST neutron-calibration data a variation of the QFs among different CaWO ₄ 4 single crystals was found. For typical CRESST detectors the QFs in the region-of-interest (10–40 keV) are \hbox QF_O^ROI=(11.2± 0.5) QF O ROI = ( 11.2 ± 0.5 ) %, \hbox QF_Ca^ROI=(5.94± 0.49) QF Ca ROI = ( 5.94 ± 0.49 ) % and \hbox QF_W^ROI=(1.72± 0.21) QF W ROI = ( 1.72 ± 0.21 ) %. The latest CRESST data (run32) is reanalyzed using these fundamentally new results on light quenching in CaWO ₄ 4 having moderate influence on the WIMP analysis. Their relevance for future CRESST runs and for the clarification of previously published results of direct dark matter experiments is emphasised.

Citations

• Search for low-mass WIMPs with EDELWEISS-II heat-and-ionization detectors
• Review of mathematics, numerical factors, and corrections for dark matter experiments based on elastic nuclear recoil
• First results from the LUX dark matter experiment at the Sanford Underground Research Facility
• Particle dark matter: evidence, candidates and constraints
• Model for cryogenic particle detectors with superconducting phase transition thermometers

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