Contribution of the electron-phonon interaction to Lindhard energy partition at low energy in Ge and Si detectors for astroparticle physics applications

TL;DR

This paper investigates how transient thermal effects, specifically electron-phonon interactions, influence the energy partition in germanium and silicon detectors at low energies, affecting predictions relevant for astroparticle physics.

Contribution

It introduces a thermal spike model to account for transient effects on energy partition, refining Lindhard's predictions at low recoil energies in Ge and Si detectors.

Findings

Transient effects modify energy partition curves at low energies.

Temperature-dependent energy exchange influences the partitioning.

Model aligns with many experimental data sets.

Abstract

The influence of the transient thermal effects on the partition of the energy of selfrecoils in germanium and silicon into energy eventually given to electrons and to atomic recoils respectively is studied. The transient effects are treated in the frame of the thermal spike model, which considers the electronic and atomic subsystems coupled through the electron - phonon interaction. For low energies of selfrecoils, we show that the corrections to the energy partition curves due to the energy exchange during the transient processes modify the Lindhard predictions. These effects depend on the initial temperature of the target material, as the energies exchanged between electronic and lattice subsystems have different signs for temperatures lower and higher than about 15 K. Many of the experimental data reported in the literature support the model.