MONTE-CARLO SIMULATION OF THE TRANSPORT OF FAST ELECTRONS AND POSITRONS IN SOLIDS

We give a detailed description of a Monte Carlo simulation method for the transport of high energy (1-50 keV) positrons and electrons in solids using either the Penn dielectric loss function or the Lindhard dielectric function to model inelastic scattering and elastic scattering cross sections obtained from a partial wave expansion. Results for positron implantation and backscattering for Be, Al, Cu, Ag and Au are presented. Simulation results and experiments for positrons are found to be in very good agreement, which confirms the accuracy of the Penn model for describing inelastic scattering of positrons in solids. In the case of electrons agreement between simulated and experimental backscattering probabilities is reasonable but there are significant discrepancies which can be explained by the neglect of the indistinguishability of electrons in the Penn model.