Development of MMC-based lithium molybdate cryogenic calorimeters for AMoRE-II

Abstract

The AMoRE collaboration searches for neutrinoless double beta decay of ${}^{100}$Mo using molybdate scintillating crystals via low temperature thermal calorimetric detection. The early phases of the experiment, AMoRE-pilot and AMoRE-I, have demonstrated competitive discovery potential. Presently, the AMoRE-II experiment, featuring a large detector array with about 90 kg of ${}^{100}$Mo isotope, is under construction. This paper discusses the baseline design and characterization of the lithium molybdate cryogenic calorimeters to be used in the AMoRE-II detector modules. The results from prototype setups that incorporate new housing structures and two different crystal masses (316 g and 517 - 521 g), operated at 10 mK temperature, show energy resolutions (FWHM) of 7.55 - 8.82 keV at the 2.615 MeV ${}^{208}$Tl $\gamma$ line, and effective light detection of 0.79 - 0.96 keV/MeV. The simultaneous heat and light detection enables clear separation of alpha particles with a discrimination power of 12.37 - 19.50 at the energy region around ${}^6$Li(n, $\alpha$)${}^3$H with Q-value = 4.785 MeV. Promising detector performances were demonstrated at temperatures as high as 30 mK, which relaxes the temperature constraints for operating the large AMoRE-II array.

References in corpus (9)

• Toward the discovery of matter creation with neutrinoless double-beta decay
• Neutrino Mass Ordering from Oscillations and Beyond: 2018 Status and Future Prospects
• Shape and pairing fluctuations effects on neutrinoless double beta decay nuclear matrix elements
• First Results from the AMoRE-Pilot neutrinoless double beta decay experiment
• Shell-model calculation of ${}^{100}$Mo double-$\beta$ decay
• Superconducting detectors for rare event searches in experimental astroparticle physics
• Status and performance of the AMoRE-I experiment on neutrinoless double beta decay
• Growth and development of pure Li2MoO4 crystals for rare event experiment at CUP
• Purification and recovery of 100MoO3 in crystal production for AMoRE experiment