Charge exchange of O− scattering on a Si(111) surface
School of Nuclear Science and Technology, Lanzhou University, 730000 Lanzhou, P.R. China
Received: 29 January 2015
Received in final form: 19 April 2015
Published online: 11 September 2015
The experiment of 10.5–22.5 keV negative oxygen ions scattering on a Si(111) surface at a scattering angle of 38° has been performed. O atoms, O− and O+ ions can be distinguished in the mixed scattered beams using the position-sensitive technique. The fractions of scattered O atoms, O− and O+ ions vary obviously with both the incident angle and incident energy. For specular scattering at different incident energies, the O− fraction presents a peak structure and obeys well an exponential dependence on the inverse of the normal velocity component of the projectile. It indicates that the initial negative ion is non-adiabatically formed at short distances related to the incident velocity effects and subsequently decays at large distances via resonant ionization.
Key words: Atomic and Molecular Collisions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2015