Li2100deplMoO4 Scintillating Bolometers for Rare-Event Search Experiments

Sensors (Basel). 2023 Jun 9;23(12):5465. doi: 10.3390/s23125465.

Abstract

We report on the development of scintillating bolometers based on lithium molybdate crystals that contain molybdenum that has depleted into the double-β active isotope 100Mo (Li2100deplMoO4). We used two Li2100deplMoO4 cubic samples, each of which consisted of 45-millimeter sides and had a mass of 0.28 kg; these samples were produced following the purification and crystallization protocols developed for double-β search experiments with 100Mo-enriched Li2MoO4 crystals. Bolometric Ge detectors were utilized to register the scintillation photons that were emitted by the Li2100deplMoO4 crystal scintillators. The measurements were performed in the CROSS cryogenic set-up at the Canfranc Underground Laboratory (Spain). We observed that the Li2100deplMoO4 scintillating bolometers were characterized by an excellent spectrometric performance (∼3-6 keV of FWHM at 0.24-2.6 MeV γs), moderate scintillation signal (∼0.3-0.6 keV/MeV scintillation-to-heat energy ratio, depending on the light collection conditions), and high radiopurity (228Th and 226Ra activities are below a few µBq/kg), which is comparable with the best reported results of low-temperature detectors that are based on Li2MoO4 using natural or 100Mo-enriched molybdenum content. The prospects of Li2100deplMoO4 bolometers for use in rare-event search experiments are briefly discussed.

Keywords: bolometer; cryogenic detector; crystal scintillator; lithium molybdate; molybdenum depleted in 100Mo; rare events.

MeSH terms

  • Ions
  • Isotopes
  • Lithium
  • Molybdenum*
  • Radium*
  • Scintillation Counting / methods

Substances

  • Molybdenum-100
  • Molybdenum
  • Radium-226
  • Isotopes
  • Radium
  • Lithium
  • Ions

Grants and funding

This work was supported by the European Commission (Project CROSS, Grant No. ERC-2016-ADG, ID 742345). This work was also supported by the National Research Foundation of Ukraine under Grant No. 2020.02/0011 and by the National Academy of Sciences of Ukraine within the framework of the project “Development of bolometric experiments for the search for double beta decay”, Grant No. 0121U111684. Y.A.B., V.D.G., E.P.M., and V.N.S. were supported by the Ministry of Science and Higher Education of the Russian Federation (N121031700314-5).