Characterization of ZnSe scintillating bolometers for Double Beta Decay

Abstract

ZnSe scintillating bolometers are good candidates for future Double Beta Decay searches, because of the 82 Se high Q-value and thanks to the possibility of alpha background rejection on the basis of the scintillation signal. In this paper we report the characteristics and the anomalies observed in an extensive study of these devices. Among them, an unexpected high emission from alpha particles, accompanied with an unusual pattern of the light vs. heat scatter plot. The perspectives for the application of this kind of detectors to search for the Neutrinoless Double Beta Decay of 82 Se are presented.

Neutrinoless Double Beta Decay: An Extreme Challenge

“…One of the most striking features of ZnSe is the abnormal QF, higher than 1 unlike all the other studied compounds. Although not really welcome, this unexpected property does not degrade substantially the discrimination power (see in [6]) of this material compared to the others and makes it compatible with the requirement of a high sensitivity experiment. An additional very useful feature is the possibility to perform α/β discrimination on the basis of the temporal structure of the signals, both in the heat and light channel as seen in Fig.…”

Highly sensitive bolometers for rare alpha decay studies

“…The calibration of the light detector was obtained by means of a weak 55 Fe source placed close to the Ge wafer that illuminated homogeneously the face. This experimental setup was used to study many scintillating bolometers for neutrinoless double beta decay such as ZnMoO 4 [2], ZnSe [3], CdWO 4 [4] and CaMoO 4 [5]. This setup was also used to study materials surface contaminations with a Bi 4 Ge 3 O 12 (BGO) crystal [6].…”

Neutrinoless double-beta decay search with CUORE and CUORE-0 experiments

“…To this end, additional detection channels are needed, since the absorber does not respond differently for energy releases of different particle types. To distinguish signal electrons from α background, light emission can be used, either from Cherenkov radiation [22,23] or scintillation light [24,25,28,29], where the auxiliary light detector is usually another bolometer facing the main one. Recently new studies on scintillating bolometers showed the possibility to distinguish α from β/γ particles without light readout thanks to a different time-dependent shape of the heat signal [30,31].…”