Geant4 physics processes for microdosimetry simulation: Very low energy electromagnetic models for electrons in silicon

The Energy-Loss Function (ELF) of silicon is used to calculate differential and total inelastic cross-sections of incident electrons. The model is validated in the 50 eV–50 keV incident energy range by comparing the inelastic cross-sections, stopping powers, and ranges to experimental and calculated data from the literature. It is applicable down to 16.7 eV. The cross sections are then used to simulate low-energy electron tracks in silicon with Geant4, using a similar implementation as the Geant4-DNA extension; this new Geant4 extension is called MuElec. Generation of low-energy electrons is clearly seen. The obtained ranges are consistent with experimental data.