Ionization of the 3dσ State and K-L Vacancy Sharing in Heavy Ion-Atom Collisions

Abstract

In the quasimolecular picture the ionization of the 3dσ diabatic state is the origin of the creation of K- and L-shell vacancies in the lighter and heavier collision partner, respectively, in slow and very asymmetric ion-atom collisions. To explain this phenomenon the extended united atom (UA) model has been used recently (Briggs 1975, Meyerhof 1978). During the separation, the 3dσ vacancies are shared among the K- and L-shells of the collision partners. The two-state molecular orbital (MO) models of Demkov-Meyerhof or of Nikitin were used in the description of that process (Demkow 1964, Meyerhof 1973, Nikitin 1970, Meyerhof et al 1978, Woerlee et al 1978, Fortner 1979). Fritsch and Wille (1979) showed the limitations of these two-state-MO models. In the present work we report experiments carried out for heavy collision systems near the K-L level matching. Both “swapped” and “unswapped” cases, according to the relative position of the ls state of the lighter collision partner and the 2p state of the heavier one were investigated.