Theory of Electron Emission from Solids by Proton and Electron Bombardment

Abstract

Abstract Using the microscopic theory of kinetic ion‐induced electron emission (IIEE) and secondary electron emission (SEE) developed earlier an improved description of transport processes of excited electrons is given. Electron–electron scattering rates are calculated including the dynamic screening of the Coulomb interaction. The resulting enhancement of these scattering rates compared with the Thomas‐Fermi approximation leads to new statements concerning the magnitude of contributions from different excitation mechanisms. The theory is applied to polycrystalline aluminum. For the proton‐induced electron emission the primary energies are limited to 20 to 800 keV and for the SEE to 1 to 2 keV. Compared to the other excitation mechanisms the excitation of single conduction electrons for IIEE (H + → Al) and the excitation from inner shells for SEE produces the largest contribution to the yield, respectively. A better agreement between theory and experiment is achieved for both emission phenomena.