Negative-continuum dielectronic recombination into excited states of highly charged ions

摘要

The recombination of a free electron into a bound state of bare, heavy nucleus under simultaneous produc-tion of bound-electron—free-positron pair is studied within the framework of relativistic first-order perturbation theory. This process, denoted as "negative-continuum dielectronic recombination" leads to a formation of not only the ground but also the singly and doubly excited states of the residual heliumlike ion. The contributions from such an excited state capture to the total as well as angle-differential cross sections are studied in detail. Calculations are performed for the recombination of (initially) bare uranium U~(92+) ions and for a wide range of collision energies. From these calculations, we find almost 75% enhancement of the total recombination probability if the excited ionic states are taken into account.