Events near the cathode and anode surfaces of a coplanar grid CdZnTe detector are identifiable by means of the interaction depth information encoded in the signal amplitudes. However, the amplitudes cannot be used to identify events near the lateral surfaces. In this paper a method is described to identify lateral surface events by means of their pulse shapes. Such identification allows for discrimination of surface alpha particle interactions from more penetrating forms of radiation, which is particularly important for rare event searches. The effectiveness of the presented technique in suppressing backgrounds due to alpha contamination in the search for neutrinoless double beta decay with the COBRA experiment is demonstrated.
@article{arxiv.1401.5844,
title = {Pulse-shape discrimination of surface events in CdZnTe detectors for the COBRA experiment},
author = {Matthew Fritts and Jan Tebrügge and Jürgen Durst and Joachim Ebert and Claus Gößling and Thomas Göpfert and Daniel Gehre and Caren Hagner and Nadine Heidrich and Michael Homann and Tobias Köttig and Till Neddermann and Christian Oldorf and Thomas Quante and Silke Rajek and Oscar Reinecke and Oliver Schulz and Jan Timm and Björn Wonsak and Kai Zuber},
journal= {arXiv preprint arXiv:1401.5844},
year = {2015}
}