K-L and L-K Vacancy Sharing in Ion-Atom Collisions

The molecular model has been very successful in explaining the production of atomic vacancies in low energy ion-atom collisions. One area of active investigation involves the sharing of inner-shell vacancies between two collision partners. The sharing results when a vacancy, which has been produced at some smaller internuclear distance, is transferred from one molecular orbital (MO) to another during the separation of the two collision partners. K-shell vacancy sharing in near symmetric collisions due to radial coupling between the 1s¿ and 2p¿ MOs has been studied extensively. Meyerhof derived a simple formula using a parameterization of the Demkov formalism, which was very successful in explaining a large body of data on K-K vacancy sharing. In this paper I will summarize the current situation involving sharing of K and L vacancies in highly asymmetric collisions (Z1/Z2 ¿ 2).