Interference of autoionizing transitions in time-dependent fields

Abstract

A semiclassical description is presented for the decay of autoionizing states which are excited in ion-atom and electron-atom collisions and decay in the time-dependent field of the slowly receding charged collision partner. Analytical formulae are derived to describe electron spectra resulting from such autoionizing transitions. Calculations using these formulae are carried out and compared with various measurements, reported earlier: electron spectra, resulting from He+/He collisions, and electron spectra and excitation functions of Rydberg states excited in electron/He collisions. The good agreement between measurements and calculations shows that within a simple potential curve model all experimentally observed features can be understood quantitatively if only all possible interferences of the various contributions to the electron spectra are properly taken into account.