EPJ Web of Conferences 65, 04005 (2014)
https://doi.org/10.1051/epjconf/20136504005

Characterization of a ZnSe scintillating bolometer prototype for neutrinoless double beta decay search

¹ Centre de Sciences Nucléaires et de Sciences de la Matière, CNRS and Université Paris-Sud, F-91405 Orsay, France
² Istituto Nazionale di Fisica Nucleare, Sezione di Milano-Bicocca, I-20126 Milano, Italy
³ Service de Physique des Particules, CEA Saclay, F-91191 Gif-sur-Yvette, France
⁴ Università degli Studi dell’Insubria, Dipartimento di Scienza e Alta Tecnologia, I-22100 Como, Italy

^a e-mail: margherita.tenconi@csnsm.in2p3.fr

Published online: 10 January 2014

Abstract

As proposed in the LUCIFER project, ZnSe crystals are attractive materials to realize scintillating bolometers aiming at the search for neutrinoless double beta decay of the promising isotope ⁸²Se. However, the optimization of the ZnSe-based detectors is rather complex and requires a wide-range investigation of the crystal features: optical properties, crystalline quality, scintillation yields and bolometric behaviour. Samples tested up to now show problems in the reproducibility of crucial aspects of the detector performance. In this work, we present the results obtained with a scintillating bolometer operated aboveground at about 25 mK. The detector energy absorber was a single 1 cm³ ZnSe crystal. The good energy resolution of the heat channel (about 14 keV at 1460 keV) and the excellent alpha/beta discrimination capability are very encouraging for a successful realization of the LUCIFER program. The bolometric measurements were completed by optical tests on the crystal (optical transmission and luminescence measurements down to 10 K) and investigation of the crystalline structure. The work here described provides a set of parameters and procedures useful for a complete pre-characterization of ZnSe crystals in view of the realization of highly performing scintillating bolometers.