A COMPREHENSIVE THEORY OF ELECTRON-EMISSION IN ION-ATOM COLLISIONS

The channel-distorted wave method is combined with a two-centre description of the ejected electron state to embrace target ionization as well as capture-to-continuum aspects of the ionization process in energetic ion-atom collisions. The target-ionization peak, the electron-capture-to-continuum cusp and the binary ridge appear in the appropriate regions of momentum space of the ejected electron but each one of these features is perturbed by the presence of the other collision partner. In the cusp and in the binary-ridge regions, the essential effect of the residual target ion is represented by a modified Compton profile in which the momentum distribution of the initial electron state has been replaced by a corresponding form factor. Similarly, in the region of low electron energies with respect to the target nucleus, the standard expression for target ionization is modulated by a suitable off-energy-shell factor. The present theory agrees well with experimental data.