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

The channel-distorted wave method is combined with a two-centre descri ption of the ejected electron state to embrace target ionization as we ll as capture-to-continuum aspects of the ionization process in energe tic ion-atom collisions. The target-ionization peak, the electron-capt ure-to-continuum cusp and the binary ridge appear in the appropriate r egions 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 i n which the momentum distribution of the initial electron state has be en replaced by a corresponding form factor. Similarly, in the region o f low electron energies with respect to the target nucleus, the standa rd expression for target ionization is modulated by a suitable off-ene rgy-shell factor. The present theory agrees well with experimental dat a.