First Tests of Li2WO4 Bolometric Detectors Using MMC Sensors for the Detection of CEνNS

Coherent elastic neutrino-nucleus scattering (CE ν NS), detected for the first time more than 40 years after its prediction, represents an experimental challenge because of its signature: a single nuclear recoil with energy in the range of 10 eV to a few 10’s keV on average. One of the main features of CE ν NS is its cross section, around two orders of magnitude higher compared with the inverse β decay. BASKET (Bolometers At Sub keV Energy Threshold) project aims at investigating cryogenic calorimeters for the CE ν NS detection, able to maintain the background level below the expected signature while being operated in above ground conditions in close vicinity to a nuclear reactor. The main requirements for such detectors are a low enough energy threshold of O(10 eV), and a fast signal rise time in the range of 0.1–1 ms to achieve good timing resolution and hence good mitigation of pile-up events. In this article, we report on the first tests of a prototype detector coupling a Li 2 WO 4 crystal to a magnetic metallic calorimeter (MMC) thermal sensor.