Phenomenological model for predicting the energy resolution of neutron-damaged coaxial HPGe detectors

TL;DR

This paper presents a phenomenological model to predict the energy resolution deterioration of coaxial HPGe detectors caused by neutron-induced damage, based on a single trap parameter related to hole trapping probability.

Contribution

The paper introduces a simple, dimensionless parameter-based model that predicts energy resolution loss in neutron-damaged germanium detectors regardless of their size or type.

Findings

Model accurately predicts energy resolution degradation with neutron fluence.

Single trap parameter effectively characterizes damage effects.

Applicable to various detector geometries and neutron exposure levels.

Abstract

The peak energy resolution of germanium detectors deteriorates with increasing neutron fluence. This is due to hole capture at neutron-created defects in the crystal which prevents the full energy of the gamma-ray from being recorded by the detector. A phenomenological model of coaxial HPGe detectors is developed that relies on a single, dimensionless parameter that is related to the probability for immediate trapping of a mobile hole in the damaged crystal. As this trap parameter is independent of detector dimensions and type, the model is useful for predicting energy resolution as a function of neutron fluence.