First test of a Li2_2WO4_4(Mo) bolometric detector for the measurement of coherent neutrino-nucleus scattering

International audienceThe first observation of coherent elastic neutrino-nucleus scattering (CE ν NS), reported by the COHERENT Collaboration in 2017, paved the way for a new generation of experiments using reactor ν̄e and aiming at precisely measuring this process. In this context, the BASKET (Bolometers At Sub-KeV Energy Thresholds) R&D; project investigates the use of cryogenic detectors for a reactor CE ν NS experiment. This article reports on the first test of a Mo-doped lithium tungstate scintillating bolometer ( ⊘ 18 × 7 mm, 8 g), performed in an aboveground laboratory at CSNSM, Orsay (France). The detector bolometric performance (energy and time response, particle identification capabilities) and radiopurity have been studied and confirm the promising potential of lithium tungstate-based bolometric detectors for the measurement of CE ν NS at reactors

Separating 39Ar{^{39}\hbox {Ar}} from 40Ar{^{40}\hbox {Ar}} by cryogenic distillation with Aria for dark-matter searches

International audienceAria is a plant hosting a ${350}\,\hbox {m}$ cryogenic isotopic distillation column, the tallest ever built, which is being installed in a mine shaft at Carbosulcis S.p.A., Nuraxi-Figus (SU), Italy. Aria is one of the pillars of the argon dark-matter search experimental program, lead by the Global Argon Dark Matter Collaboration. It was designed to reduce the isotopic abundance of ${^{39}\hbox {Ar}}$ in argon extracted from underground sources, called Underground Argon (UAr), which is used for dark-matter searches. Indeed, ${^{39}\hbox {Ar}}$ is a $\beta$-emitter of cosmogenic origin, whose activity poses background and pile-up concerns in the detectors. In this paper, we discuss the requirements, design, construction, tests, and projected performance of the plant for the isotopic cryogenic distillation of argon. We also present the successful results of the isotopic cryogenic distillation of nitrogen with a prototype plant