An Improved ZnMoO4 Scintillating Bolometer for the Search for Neutrinoless Double Beta Decay of 100Mo
Creators
- 1. Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- 2. Institute for Nuclear Research, MSP 03680 Kyiv, Ukraine
- 3. Kyiv National Taras Shevchenko University, MSP 03680 Kyiv, Ukraine
- 4. Nikolaev Institute of Inorganic Chemistry, 630090 Novosibirsk, Russia
- 5. Centre de Spectrome ́trie Nuclaire et de Spectrome ́trie de Masse, CNRS and Universite ́ Paris-Sud, F-91405 Orsay, France and Universita` dell’Insubria, Dipartimento di Fisica e Matematica, I-22100 Como, Italy
- 6. Centre de Spectrome ́trie Nuclaire et de Spectrome ́trie de Masse, CNRS and Universite ́ Paris-Sud, F-91405 Orsay, France
- 7. Istituto Nazionale di Fisica Nucleare, Sezione di Milano-Bicocca, I-20126 Milano, Italy
- 8. Universita` dell’Insubria, Dipartimento di Fisica e Matematica, I-22100 Como, Italy
Description
We present a prototype scintillating bolometer for the search for neutrino-less double β decay of 100Mo, consisting of a single ≈5 g ZnMoO4 crystal operated aboveground in the 20–30 mK temperature range. The scintillation light is read out by two thin Ge bolometers. The phonon signals are collected by NTD Ge thermistors. The ZnMoO4 crystal was grown with an advanced method (low-thermal-gradient Czochralski technique) and after purification of molybdenum. The results are very encouraging: the intrinsic energy resolution of the heat channel is ≈800 eV FWHM, the α/β rejection factor (crucial for background suppression) is better than 99.9% in the region of interest for double β decay (≈3 MeV), and the radiopurity of ZnMoO4 looks substantially improved with respect to previous devices.
Files
Restricted
The record is publicly accessible, but files are restricted to users with access.