Direct observation of multiple L-shell vacancy effects in energetic heavy ion collisions

Abstract Observations have been made of soft L X-ray spectra resulting from collisions of 8–20 MeV oxygen ions and Ni, Cu and Zn atoms. These observations provide confirmation of the multiple L-shell vacancies proposed to explain recent experimental determinations of K-shell X-ray energy shifts in such collisions. The energy dependence of the single vacancy shifts indicate that the probability of outer shell ionization is a decreasing function of ion energy in this energy range.