Inner-Shell Vacancy Production in Ion–Atom Collisions

Abstract

This chapter reviews the understanding of the process of K-shell vacancy production in ion–atom collisions. It is necessary to discuss the role of K-shell electron transfer along with excitation and ionization processes as the mechanisms of removing the K-shell electrons. The chapter presents ionization in a one-to-one context with the K-shell electron transfer process for collisions from the very asymmetric systems, where ionization is the dominant K-vacancy production mechanism, to near-symmetric systems, where K-electron transfer is the dominant mechanism. Experimental data from heavy-ion collisions are presented in parallel to selective data from the simple collisions such as H + + H and H + + He. This is important in view that many theoretical models have been developed originally for simple collision systems. Because of the range of parameters that can be controlled in heavy-ion collisions, heavy-ion collision data provide new grounds for testing these and some new theoretical models. The chapter presents a review of the experimental methods of measuring K-shell vacancy production cross sections and measurements where excitation, ionization, and charge transfer cross sections can be identified. The status of the theory of electron transfer in ion–atom collisions is reviewed and comparisons between theories are discussed in the chapter.