Dispersion-equation approach to obtaining polarization potentials for quantum-mechanical electron-scattering calculations

The polarization potential for electron-neon scattering is calculated from a dispersion relation relating the real and imaginary parts of the optical potential. The input to the calculation is the absorption potential of Green, Rio, and Ueda. The polarization and absorption potentials, along with a Hartree-Fock static potential and an exchange potential calculated by the semiclassical exchange approximation, are used to predict integral and differential cross sections for elastic scattering at impact energies 30-3000 eV. The results are compared to those obtained with Hartree-Fock adiabatic polarization and in the static-exchange-plus-absorption approximation. The dispersion-relation polarization potential is more successful than either of these models in reproducing the energy dependence of the integral and small-angle differential cross sections over the whole energy range. At 50 eV and higher the calculated values of the large-angle differential cross sections are also reasonably accurate.