ANGULAR-DEPENDENT ENERGY-DISTRIBUTIONS FOR BACKSCATTERED ELECTRONS - CALCULATION OF THE SURFACE-IONIZATION

An equation for angular-dependent energy distributions of backscattere d electrons is presented. Extensive Monte Carlo simulations lead to a simple description for the energy distribution. A comparison of the ne w expression with experimentally derived curves, Monte Carlo results, and an analytical model is performed. The newly derived energy distrib utions are used for the calculation of the surface ionization Phi(0) f or oblique angle of incidence. For normal incidence, a comparison with several published experimental data leads to a mean value for the dev iation of < 4%. For tilted specimens the results are compared with fin dings of other authors.