Inelastic Scattering Cross Sections for 200- and 400-keV Electrons

Abstract

With 200- and 400-keV electrons incident on thin targets of aluminum, copper, tin, and gold, experimental data are given for the pulse-height distributions produced in a silicon detector by the electrons scattered at angles of 40\ifmmode^\circ\else\textdegree\fi{}, 90\ifmmode^\circ\else\textdegree\fi{}, 120\ifmmode^\circ\else\textdegree\fi{}, and 140\ifmmode^\circ\else\textdegree\fi{}. These distributions were analyzed to determine the inelastic cross sections integrated over the energies of the scattered electrons in the energy region below the elastic peak. This lower energy region involves energy transfers that are large compared to the atomic binding energies, and most probably involves atomic ionization processes. The results show that these inelastic scattering cross sections increase sharply for angles larger than 90\ifmmode^\circ\else\textdegree\fi{}, so that the ratio of the inelastic to the elastic cross sections becomes larger than unity. In addition, these large-angle inelastic cross sections increase with the atomic number of the target and with the average binding energy per target electron. Because of the unavailability of accurate calculations for this process, comparisons are made with the M$\mathrm{l}$ler cross sections for electron-electron scattering in order to demonstrate how atomic binding effects influence large-angle inelastic scattering.