The energy dependence of relativistic nonradiative electron capture

Abstract

The energy dependence of the nonradiative electron capture cross section is discussed for relativistic collision energy. A simple analytic expression for the cross section is obtained for inner-shell transitions using second-order perturbation theory. We have confirmed that the leading-order term is found to have the following energy dependence: . This is attributed to a combination of kinematic features of the process and retardation effects. For ultra-relativistic collision energies and small nuclear charges, electron capture without change of spin is the dominant transition.