Low-Temperature Relative Reflectivity Measurements of Reflective and Scintillating Foils used in Rare Event Searches

Abstract

In this work we investigate the reflectivity of highly reflective multilayer polymer foils used in the CRESST experiment. The CRESST experiment searches directly for dark matter via operating scintillating CaWO${}_4$ crystals as targets for elastic dark matter-nucleon scattering. In order to suppress background events, the experiment employs the so-called phonon-light technique which is based on the simultaneous measurement of the heat signal in the main CaWO${}_4$ target crystal and of the emitted scintillation light with a separate cryogenic light detector. Both detectors are surrounded by a highly reflective and scintillating multilayer polymer foil to increase the light collection efficiency and to veto surface backgrounds. While this study is motivated by the CRESST experiment, the results are also relevant for other rare event searches using scintillating cryogenic bolometers in the field of the search of dark matter and neutrinoless double beta decay ($0\nu \beta \beta$). In this work a dedicated experiment has been set up to determine the relative reflectivity at 300 K and 20 K of three multilayer foils ("VM2000", "VM2002", "Vikuiti") produced by the company 3M. The intensity of a light beam reflected off the foil is measured with a CCD camera. The ratio of the intensities at 300 K and 20 K corresponds to the relative reflectivity change. The measurements performed in this work show no significant change in the reflectivity with temperature for all foils studied.

arXiv comment6 pages, 7 figures

References in corpus (6)

• Results on light dark matter particles with a low-threshold CRESST-II detector
• Limits on WIMP dark matter using scintillating CaWO4 cryogenic detectors with active background suppression
• Results on low mass WIMPs using an upgraded CRESST-II detector
• Commissioning Run of the CRESST-II Dark Matter Search
• Radiopurity of CaWO${}_4$ Crystals for Direct Dark Matter Search with CRESST and EURECA
• In-situ study of light production and transport in phonon/light detector modules for dark matter search

Cited by in corpus (4)

• CUPID-0: the first array of enriched scintillating bolometers for 0νββdecay investigations
• Design and construction of a new detector to measure ultra-low radioactive-isotope contamination of argon
• Tetraphenyl Butadiene Emanation and Bulk Fluorescence from Wavelength Shifting Coatings in Liquid Argon
• Simulations of the nEDM@SNS light collection system efficiency