Degree of the neutralization of highly charged Ar ions scattered at different angles from a Au surface

We investigated the influence of the scattering geometry and incident energ y on the neutralization degree of highly charged Arq+ (q= 7-13) ions scatte red from single Au crystal. It is found that at large scattering angle the probability of detecting multiple charged ions after interaction is high. W e point out that besides the interaction time, additional ionization in har d collisions is also important. The results are supported by model calculat ions which consider electron exchange processes along the ion trajectory.