Characterization of High Purity Germanium Point Contact Detectors with Low Net Impurity Concentration

TL;DR

This paper investigates how ultra-high purity germanium point-contact detectors with low net impurity concentrations improve pulse-shape discrimination, crucial for rare event searches like neutrinoless double beta decay.

Contribution

It demonstrates the necessity of minimal net impurity concentration for optimal pulse-shape discrimination in high purity germanium detectors.

Findings

Minimal net impurity concentration is essential for pulse-shape performance.

High purity germanium detectors enable low energy thresholds and excellent resolution.

Pulse-shape discrimination enhances background reduction in rare event searches.

Abstract

High Purity germanium point-contact detectors have low energy thresholds and excellent energy resolution over a wide energy range, and are thus widely used in nuclear and particle physics. In rare event searches, such as neutrinoless double beta decay, the point-contact geometry is of particular importance since it allows for pulse-shape discrimination, and therefore for a significant background reduction. In this paper we investigate the pulse-shape discrimination performance of ultra-high purity germanium point contact detectors. It is demonstrated that a minimal net impurity concentration is required to meet the pulse-shape performance requirements.