Dynamic Ionization and Auger Transitions in the Quasi-Molecule during Ne+–Ne Collisions

Abstract

The exponential component of the electron spectrum during Ne–Ne collisions is shown to be associated with the electron transitions from the autoionization term to the continuum. The characteristics of this term have been determined. The exponential shape of the spectrum is explained by the absence of interference between the transition amplitudes as the particles come close together and fly apart due to a high transition probability. For Auger transitions in the quasi-molecule we have determined the dependence of the mean Auger transition energy on the reached internuclear distance, which agrees well with the results of energy level calculations for the Ne–Ne system, and the dependence of the weighted mean Auger transition probability on the observed electron energy Ee. We show that the transition probability decreases significantly with increasing Ee as the internuclear distance decreases, apparently, due to a decrease in the overlap integrals of the wave functions for the interacting electrons. Our analysis allows a coherent picture of ionization in collisions of intermediate-mass ions with keV energies to be formed.