Validation of Geant4 simulation of electron energy deposition

TL;DR

This study validates Geant4 simulations of electron energy deposition against precise experimental data, highlighting differences across versions and identifying optimal models for accurate results in low-energy electron scenarios.

Contribution

It provides a comprehensive validation of Geant4 electron energy deposition models against experimental data, guiding future applications and improvements.

Findings

Best compatibility with data achieved using Geant4 9.1 with EEDL/EPDL models.

Significant differences observed in longitudinal energy deposition patterns across Geant4 versions.

Total energy deposited shows smaller variation across versions, except Geant4 9.4.

Abstract

Geant4-based simulations of the energy deposited by electrons in various materials are quantitatively compared to high precision calorimetric measurements taken at Sandia Laboratories. The experimental data concern electron beams of energy between a few tens of keV and 1 MeV at various incidence angles. Two experimental scenarios are evaluated: the longitudinal energy deposition pattern in a finely segmented detector, and the total energy deposited in a larger size calorimeter. The simulations are produced with Geant4 versions from 9.1 to 9.6; they involve models of electron-photon interactions in the standard and low energy electromagnetic packages, and various implementations of electron multiple scattering. Significant differences in compatibility with experimental data are observed in the longitudinal energy deposition patterns produced by the examined Geant4 versions, while the total deposited energy exhibits smaller variations across the various Geant4 versions, with the exception Geant4 9.4. The validation analysis, based on statistical methods, shows that the best compatibility between simulation and experimental energy deposition profiles is achieved using electromagnetic models based on the EEDL and EPDL evaluated data libraries with Geant4 9.1. The results document the accuracy achievable in the simulation of the energy deposited by low energy electrons with Geant4; they provide guidance for application in similar experimental scenarios and for improving Geant4.