Elastic scattering of slow electrons by helium

Abstract

The optical potential model of Pu and Chang (1966) is extended to include EPV diagrams. Calculations are carried out for the s, p and d wave phase shifts at energies up to 17 eV. The results for s and p waves are in close agreement with those of other recent calculations and, with a phase shift analysis of experimental data. The d wave results lie between the full polarized orbital and the Green function expansion results. It is shown that third order diagrams are required for an accurate evaluation of the static polarizability, yielding alpha =1.372 a₀³, and estimates are made of the third order corrections to the d-wave phase shift, which brings the optical potential values into good agreement with the full polarized orbital results.