A THEORETICAL TREATMENT FOR THE DYNAMICS OF NEAR-RESONANT CHARGE-EXCHANGE IN GAS-SURFACE SCATTERING

A new approach for solving the problem of the dynamics of near-resonan t charge exchange occurring in gas-surface collisions is presented for two electronic state system. This theory is based on Micha's common e ikonal formalism which gives the evolution of the transition amplitude s and the nuclear trajectories. In this new theoretical treatment, the quadratic forms method in linear analysis is used for calculating the electronic transition amplitudes. The results show that a large part of the calculation can be carried out analytically. Since such a calcu lation only requires a small computational efforts, it is thus possibl e to carry out extensive parameter variation in an assumed potential f unction in order to fit calculations to experiments. This method was a pplied to scattering of Na atom from W(110) surface. The oscillatory b ehavior of transition probability with angular frequency omega(t) is a lso analysed in detail and discussed. (C) 1997 Elsevier Science B.V.