We have measured the number statistics of emitted electrons in coincidence with the projectile scattering angle distribution for multiply charged slow Ar ions scattered off an Au(111) surface at grazing incidence. The comparison of the electron statistic spectra for different projectile exit and incidence angles permits a separation of potential and kinetic electron emission. A molecular dynamics simulation allows to associate the multiple electron emission with specific trajectory histories (planar and subsurface channeling, close collisions with target atoms at steps and imperfections).

• Received 16 April 1998

DOI:https://doi.org/10.1103/PhysRevLett.81.1965