Form Factors, Atomic Potentials, and Elastic Scattering

Abstract

We present a treatment of ion-atom and atom-atom potentials based on terms derived from the separated atoms or ions. The method used is an adaption of form-factor techniques developed in particle and nuclear physics. The potentials of the separated atoms or ions are derived from an independent-particle model for atoms and the resulting ion-atom and atom-atom potentials are shown to be representable as sums of exponentially shielded Coulomb potentials, or Yukawa potentials. We then calculate the differential cross sections using an eikonal model which embodies systematic analytic corrections to the Glauber approximation. Analytic results are also obtained for the scattering amplitude at nonforward angles by employing the stationary-phase approximation. The specific case of ${\mathrm{O}}^{+}$-Ar at 100 keV is treated. Exchange effects, polarization, and inelasticity are neglected.