STABILIZATION OF MULTIPLE ELECTRON-CAPTURE BY THE POSTCOLLISIONAL INCREASE OF ANGULAR-MOMENTUM OF RYDBERG ELECTRONS

Considerable work has already been devoted to multiple electron capture by highly charged ions colliding on rare gas targets in the keV energy range. In such collisions, several electrons are captured by the projectile ionic core with a binding energy which, according to some simple models, is of the order of the successive ionization potentials of the target. This produces a unique situation in which several electrons are captured in highly excited shells. The large density of levels available at such a degree of excitation opens the possibility of interesting dynamical evolution which leads to the population of doubly excited states with one of the electrons in a high lying Rydberg state (e.g. n = 10-30). In this paper we focus on the evolution of the Rydberg electron in the field of the two receding nuclei. In particular, the increase of angular momentum of the Rydberg electron is shown to be fast enough to quench the autoionization process resulting in a true capture of the two electrons.