Neutralization of slow C60+ ions in front of KCl(0 0 1) surface

Angular and charge state distributions of reflected ions are measured when 3 keV C60+ and C600 are scattered from a KCl(0 0 1) under grazing incidence. The observed angular distributions have a well defined peak at a specular angle irrespective of the azimuth angle of incidence even under the surface channeling conditions. While the ionization of C600 is completely suppressed, the observed neutralization probability of C60+ is 10–50% depending on both the angle of incidence and the azimuth angle. From the observed neutralization probabilities, position-dependent neutralization rates Pn(x  ) of C60+ in front of KCl(0 0 1) are derived for the [1 0 0] and [1 1 0] surface channeling. Both neutralization rates decrease exponentially with increasing distance x although the neutralization rate for the [1 1 0] surface channeling is about twice larger than that for the [1 0 0].