Dissipation of Potential Energy Through X-Ray Emission in Slow Highly Charged Ion-Surface Collisions

X-ray emission yields from highly charged iodine ions incident on a hydrogen terminated silicon surface were measured. It was found that the K shell vacancies were filled through x-ray transitions with the probability of approximately 100%, while only about 20% of L shell vacancies were filled through x-ray transitions and almost all the M shell vacancies were filled nonradiatively. Dissipation of the potential energy E{sub p} of an incident ion through x-ray emissions increases gradually with the number of L shell vacancies and amounts to 10% of E{sub p} for the He-like I{sup 51+} ion. 30 to 40 % of E{sub p} for I{sup 52+} and I{sup 53+} with K shell vacancies was measured to be dissipated mainly by K x-ray emissions.