100Mo-enriched Li2MoO4 scintillating bolometers for 0ν2β decay search: From LUMINEU to CUPID-0/Mo projects

Abstract

A scintillating bolometer technology based on 100Mo-enriched lithium molybdate (Li2100MoO4) crystals has been developed by LUMINEU to search for neutrinoless double-beta (0ν2β) decay of 100Mo. The results of several low temperature tests at underground environments have proved the reproducibility of high detector performance and crystal radiopurity: in particular ∼5–6 keV FWHM energy resolution and at least 9σ rejection of α’s in the vicinity of the 0ν2β decay of 100Mo (3034 keV) and below 10 µBq/kg bulk activity of 228Th and 226Ra. A modest acquired exposure (0.1 kg×yr) is a limiting factor of the LUMINEU experiment sensitivity to the 0ν2β decay half-life of 100Mo (T1/2 ≥ 0.7×1023 yr at 90% C.L.), however the two-neutrino 2β decay has been measured with the best up to-date accuracy, T1/2 = [6.92 ± 0.06(stat.) ± 0.36(syst.)l × 1018 yr. The applicability of the LUMINEU technology for a tonne-scale 0ν2β decay bolometric project CUPID is going to be demonstrated by the CUPID-0/Mo experiment with ∼5 kg of 100Mo embedded in forty 0.2 kg Li2100MoO4 scintillating bolometers. A first phase of the experiment with twenty Li2100MoO4 detectors is in preparation at the Modane underground laboratory (France) to start by the end of 2017. The original version of this article, supplied to AIP Publishing, contained an omission of two footnotes. In addition, the article was missing the following collaborations from the author listing: LUMINEU, EDELWEISS, and CUPID-0/Mo Collaborations. An updated version of this article was corrected and re-published on 25 October 2017.