Energy Distribution of Inelastically Scattered Electrons

The spectrum of electrons at low energies and large scattering angles resulting from the scattering of high-energy electrons on atoms is considered. For thin scattering foils, the dominant contributions to this spectrum come from the following processes: (1) scattering accompanied by bremsstrahlung production, (2) scattering on bound electrons, and (3) Møller scattering followed by a single nuclear Coulomb scattering. It is found that the overwhelming majority of scattered electrons of low energy (i.e., kinetic energy of the order of the rest energy) come from processes (2) and (3), thus masking the peak predicted by Parzen et al. for process (1). For high incident energy and high-$Z$ scatterers, the process (2) is dominant. It is shown that the cross section for low-energy scattered electrons from process (2) is related to the electron-electron forward-scattering cross section. This affords a means of measuring this forward-scattering cross section.