Scintillating bolometers based on ZnMoO4 and Zn100MoO4 crystals to search for 0ν2β decay of 100Mo (LUMINEU project): first tests at the Modane Underground Laboratory

D.V Poda

doi:10.1016/j.nuclphysbps.2015.09.290

Abstract

The technology of scintillating bolometers based on zinc molybdate (ZnMoO4) crystals is under development within the LUMINEU project to search for 0ν2β decay of 100Mo with the goal to set the basis for large scale experiments capable to explore the inverted hierarchy region of the neutrino mass pattern. Advanced ZnMoO4 crystal scintillators with mass of ∼0.3 kg were developed and Zn100MoO4 crystal from enriched 100Mo was produced for the first time by using the low-thermal-gradient Czochralski technique. One ZnMoO4 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 ZnMoO4 and two enriched detectors installed in the EDELWEISS set-up at the Modane Underground Laboratory (France) are presented.

Highlights

Scintillating bolometers — cryogenic detectors with a heat-light double read-out — can play a crucial role in next-generation experiments to study neutrino properties and weak interaction via investigating neutrinoless double beta (0ν2β) decay, as discussed in Refs. [1, 2]
We present results of both aboveground and underground low temperature tests of new scintillating bolometers based on natural ZnMoO4 and enriched Zn100MoO4 crystal scintillators in light of their possible application to next-generation 0ν2β decay experiments
A significant progress is achieved in development of ZnMoO4 crystal scintillators for the LUMINEU project

Summary

Introduction

Scintillating bolometers — cryogenic detectors with a heat-light double read-out — can play a crucial role in next-generation experiments to study neutrino properties and weak interaction via investigating neutrinoless double beta (0ν2β) decay, as discussed in Refs. [1, 2]. This paper describes the recent achievements in the framework of the LUMINEU programme (Luminescent Underground Molybdenum Investigation for NEUtrino mass and nature). LUMINEU is devoted to the development of a technology based on zinc molybdate (ZnMoO4) scintillating bolometer as a basis for the realization of a highsensitivity 0ν2β experiment. An important point in the realization of LUMINEU is concerned with the technology of growing high-quality radiopure large mass (0.3–0.5 kg) ZnMoO4 single crystals with the aim to produce scintillators enriched in 100Mo (Zn100MoO4). We report a significant progress in the development of ZnMoO4 crystal scintillators using deeply purified compounds (containing molybdenum with natural isotopic composition and enriched in 100Mo). We present results of both aboveground and underground low temperature tests of new scintillating bolometers based on natural ZnMoO4 and enriched Zn100MoO4 crystal scintillators in light of their possible application to next-generation 0ν2β decay experiments

Development of zinc molybdate based scintillating bolometers

Underground cryogenic measurements

Radiopurity of ZnMoO4 and Zn100MoO4 crystals

Findings

Conclusions