Unoccupied electronic states and inelastic scattering effects in SEES of tungsten single crystal

The fine structure of the experimental true secondary electron emission spectra (SEES) along the normal to a clean W(1 0 0) surface is interpreted theoretically. It is shown that the fine structure of the SEES is mainly due to the electronic structure of unoccupied high-level electronic states (above the vacuum level Evac) to which electrons are scattered or from where they are emitted. The predominant role of the bulk energy-band structure effects in the spectra formation is shown. In addition, a comparison to existing theoretical and experimental data is given.