Quantitative model of electron energy loss in XPS

A model for the inelastic-scattering cross section of electrons in XPS experiments is presented. The calculation is analogous to a previous model for reflection-electron energy-loss spectroscopy by Yubero et al. [Phys. Rev. B 53, 9719 (1996)]. The model treats the general case of photoelectron creation at arbitrary depth and with arbitrary exit angle and electron energy. The effect of the core hole as well as surface effects are included in the model. We study systematically the behavior of the model when the energy, exit angle, and depth of origin are varied. Furthermore, the effect of the core hole on the energy loss is investigated in detail. The results are compared with experimental XPS spectra from aluminum metal.