Characterization of a large CdZnTe coplanar quad-grid semiconductor detector

TL;DR

This paper characterizes a large CdZnTe coplanar quad-grid detector for gamma-ray spectroscopy, focusing on its electrical properties, energy resolution, stability, and ability to identify scattered photons, relevant for neutrinoless double beta-decay searches.

Contribution

It introduces a new large coplanar-grid CdZnTe detector design and provides comprehensive characterization data for its use in low-background gamma-ray detection.

Findings

Good energy resolution achieved

Stable operation over time demonstrated

Potential for multiple-scattered photon identification

Abstract

The COBRA collaboration aims to search for neutrinoless double beta-decay of $^{116}$Cd. A demonstrator setup with 64 CdZnTe semiconductor detectors, each with a volume of 1cm$^3$, is currently being operated at the LNGS underground laboratory in Italy. This paper reports on the characterization of a large (2 $\times$ 2 $\times$ 1.5)cm$^3$ CdZnTe detector with a new coplanar-grid design for applications in $\gamma$-ray spectroscopy and low-background operation. Several studies of electric properties as well as of the spectrometric performance, like energy response and resolution, are conducted. Furthermore, measurements including investigating the operational stability and a possibility to identify multiple-scattered photons are presented.