Doorway approximation of the optical potential: application to one-electron ion-atom scattering systems

We present a first application of the recently proposed doorway approximation of the time dependent optical potential to ion-atom collisions. The new formalism is tested for the one particle systems H+-H(1s) and H+-He+(1s). Results for elastic scattering, excitation, electron loss and ionization are compared with those of other theoretical approaches and with experimental data in the range of impact energies of 10-1000 keV for H+-He+(1s) and 2-1000 keV for H+-H(1s). (author)