Monte-Carlo modeling of excitation of the electron subsystem of Al2O3 and polyethylene after swift heavy ion impact

The Monte-Carlo (MC) model simulating the femto-second kinetics of the electron subsystem in a track of a swift heavy ion decelerated in the electronic stopping regime is developed. The complex dielectric function (CDF) formalism is used to calculate the cross sections of interactions of an ion and fast electrons with the electron subsystem of a target. It accounts for all collective modes in the electron ensemble. The applied method of CDF reconstruction from the experimental optical data provided a very good agreement of the calculated electron inelastic mean free paths with the NIST database as well as of the calculated SHI energy loss with those from SRIM and CasP codes. The MC model was applied to determine the radial distributions of delocalized electrons and their energy density in tracks of Au (2187 MeV) ions in insulators (Al2O3 and polyethylene) at different times. The femtosecond electron kinetics reveals two fronts of the spatial propagation: the primary fast delta-electrons form the front of excitations while electrons appearing due to decay of plasmons generated in a track form the second slow front following behind.