Kinetic Emission of Electrons from Monocrystalline Targets

This paper develops a single-collision theory of the emission of electrons from a metal surface subjected to high-energy ion bombardment, which gives reasonable agreement with the data of Carlston, Magnuson, Mahadevan, and Harrison, in the 1 to 10-keV energy range. The model is based upon a Thomas-Fermi-Firsov energy-transfer calculation which has been modified to include an explicit dependence upon lattice orientation. Orientation effects appear naturally, and orientation-dependent cross sections are not required, but the distribution of possible impact parameters for a particular crystal orientation is of central importance. The theory has been used to determine semiempirical interaction potentials between the moving particle and a lattice atom. These potentials are more similar to Abrahamson's atom-atom potentials than to the Gibson potentials used in radiation-damage studies.