THE MULTIPLE-SCATTERING PROBLEM IN ELECTRON COMPTON-SCATTERING ON SOLIDS

Starting from the necessity for an accurate background estimation for electron Compton scattering on solids (ECOSS) we investigated the contribution of multiple-scattering events to angle-resolved electron-energy-loss spectra at large momentum transfer. Plasmon excitation, elastic and quasielastic (i.e. phonon) scattering and single-particle excitation (i.e. Compton scattering) are included in the calculation of total scattering profiles, which is done in Fourier space with a new fast Hankel transform algorithm and standard fast Fourier transform techniques. We show that the elastic background is dominant and demonstrate that the widely used power-law fit for background subtraction fails in ECOSS.