Scintillating bolometers based on ZnMoO$_4$ and Zn$^{100}$MoO$_4$ crystals to search for 0$\nu$2$\beta$ decay of $^{100}$Mo (LUMINEU project): first tests at the Modane Underground Laboratory

TL;DR

This paper reports on the development and initial testing of ZnMoO$_4$ and enriched Zn$^{100}$MoO$_4$ scintillating bolometers aimed at detecting neutrinoless double beta decay of $^{100}$Mo, with promising performance results from underground experiments.

Contribution

First production and testing of Zn$^{100}$MoO$_4$ scintillators using low-thermal-gradient Czochralski technique for neutrino mass research.

Findings

High detection performance of tested scintillators.

Successful operation of detectors in underground laboratory.

Initial low-background measurement results.

Abstract

The technology of scintillating bolometers based on zinc molybdate (ZnMoO$_4$) crystals is under development within the LUMINEU project to search for 0$\nu$2$\beta$ decay of $^{100}$Mo with the goal to set the basis for large scale experiments capable to explore the inverted hierarchy region of the neutrino mass pattern. Advanced ZnMoO$_4$ crystal scintillators with mass of $\sim$~0.3 kg were developed and Zn$^{100}$MoO$_4$ crystal from enriched $^{100}$Mo was produced for the first time by using the low-thermal-gradient Czochralski technique. One ZnMoO$_4$ scintillator and two samples (59 g and 63 g) cut from the enriched boule were tested aboveground at milli-Kelvin temperature as scintillating bolometers showing a high detection performance. The first results of the low background measurements with three ZnMoO$_4$ and two enriched detectors installed in the EDELWEISS set-up at the Modane Underground Laboratory (France) are presented.