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 ang
le and electron energy. The effect of the core hole as well as surface
effects are included in the model. We study systematically the behavi
or of the model when the energy, exit angle, and depth of origin are v
aried. 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.