We have measured the angular polar distributions of the emitted particles (positive ions, negative ions and neutrals) in the scattering of 4 keV F+, Ne+ and Na+ from a NaCl (1 0 0) surface under an incidence angle of 2°. According to the incident ion the angular distributions for ions are shifted or not, enlarged or not, with respect to the neutral one, resulting in different charge fraction dependence. Depending on the electronic structure of the projectile, charge exchange processes of different type are involved and allow us to understand the measured distributions. We have also recorded the dependence of the charge fractions with the azimuthal angle of the incident projectile. Sensitive variations for low-indexed directions of the crystal are correlated with specific trajectories of the projectile.
Voir en ligne : NIM B, 164-165, 575-582 (2000)