Charge-carrier collective motion in germanium detectors for \beta\beta-decay searches

TL;DR

This paper investigates how charge carriers move collectively in germanium detectors, affecting signal timing and event discrimination, crucial for neutrinoless double-beta decay searches.

Contribution

It provides a comprehensive analysis of charge carrier dynamics and their impact on event topology discrimination in germanium detectors for the Legend experiment.

Findings

Charge carrier motion influences signal timing structure.

Diffusion and Coulomb effects impact event topology identification.

Study informs detector design for improved background rejection.

Abstract

The time analysis of the signal induced by the drift of charge carriers in high purity germanium detectors provides information on the event topology. Millions of charge carriers are produced in a typical event. Their initial distribution, stochastic diffusion and Coulomb self-repulsion affect the time structure of the signal. We present a comprehensive study of these effects and evaluate their impact on the event discrimination capabilities for the three geometries which will be used in the Legend experiment for neutrinoless double-beta decay.