Determining the Drift Time of Charge Carriers in P-Type Point-Contact HPGe Detectors

TL;DR

This paper introduces an algorithm to measure charge carrier drift times in p-type point contact HPGe detectors, enabling improved spatial and charge trapping characterization, which enhances energy resolution significantly.

Contribution

The paper presents a novel algorithm for measuring drift times from detector signals, allowing better charge deposition localization and charge trapping correction in HPGe detectors.

Findings

Drift times can estimate charge deposition distances.

Charge trapping effects can be corrected using measured drift times.

Energy resolution improves by up to 30% after correction.

Abstract

An algorithm to measure the drift time of charge carriers in p-type point contact (PPC) high-purity germanium (HPGe) detectors from the signals processed with a charge-sensitive preamplifier is introduced. It is demonstrated that the drift times can be used to estimate the distance of charge depositions from the point contact and to characterize losses due to charge trapping. A correction for charge trapping effects over a wide range of energies is implemented using the measured drift times and is shown to improve the energy resolution by up to 30%.