A CaMoO4 Crystal Low Temperature Detector for the AMoRE Neutrinoless Double Beta Decay Search

TL;DR

This paper presents a CaMoO4 crystal low temperature detector with high resolution and effective particle discrimination, designed to improve the search for neutrinoless double beta decay in the AMoRE experiment.

Contribution

The development and characterization of a CaMoO4 crystal detector with enhanced resolution and pulse shape discrimination for neutrinoless double beta decay searches.

Findings

Achieved 6-11 keV energy resolution for gamma peaks.

Demonstrated 7.6 sigma discrimination between alpha and beta/gamma signals.

Phonon signals with about 1 ms rise-time, improving background rejection.

Abstract

We report the development of a CaMoO4 crystal low temperature detector for the AMoRE neutrinoless double beta decay (0{\nu}\b{eta}\b{eta}) search experiment. The prototype detector cell was composed of a 216 g CaMoO4 crystal and a metallic magnetic calorimeter. An over-ground measurement demonstrated FWHM resolution of 6-11 keV for full absorption gamma peaks. Pulse shape discrimination was clearly demonstrated in the phonon signals, and 7.6 {\sigma} of discrimination power was found for the {\alpha} and \b{eta}/{\gamma} separation. The phonon signals showed rise-times of about 1 ms. It is expected that the relatively fast rise-time will increase the rejection efficiency of two-neutrino double beta decay pile-up events which can be one of the major background sources in 0{\nu}\b{eta}\b{eta} searches.