Monte Carlo simulations of positrons transmission and backscattering probabilities in nickel

Monte Carlo simulations for positron backscattering from the semi-infinite nickel with normal angle of incidence and the transmission through nickel foils of isotropically implanted positrons from a 22Na β+ source is reported. The elastic scattering cross section, have been obtained from Rutherford differential cross section where the numerical coefficient in the atomic screening parameter and spin-relativistic correction factor is taken to be variable. Inelastic scattering model was employed to simulate the energy loss using Gryzinski's semi-empirical expression and Liljequist and Gryzinski models to calculate the total inelastic scattering cross section. The simulated results and the available experimental data are found to be in reasonable agreement