New stopping power formula for intermediate energy electrons

Abstract

This study presents a new stopping power (SP) formula for electrons. In the modified Bethe-Bloch SP expression, analytical expressions for the effective charge and effective mean excitation energies (EMEE) of target atoms are used, while for the effective charge of incoming electrons, Sugiyama's semiempirical formula from Peterson and Green is used. An analytical expression for practical SP calculations is obtained using the Bethe approximation and a Thomas-Fermi model of the atom. The calculated results of the SP for electrons in some materials, such as H2O, H-2, CO2, N-2, and O-2, are compared with experimental data, together with Penelope code results and a number of other semiempirical and analytical calculations. (C) 2008 Elsevier Ltd. All rights reserved.