Positron-and electron-alkali atom low-energy elastic scattering by a JWKB-approximated polarized orbital method

Low-energy elastic cross-sections of positrons and electrons colliding with alkali atoms are calculated in a simple approach which makes use of (i) the pseudopotential formalism to reduce the many-electron alkali atom to an effective one-electron model atom, (ii) the Stone variational formulation of the polarized orbital method (POM) to calculate the polarization potentials, and (iii) the JWKB semiclassical approximation to determine the phase shifts. The calculations are straighforward and the results encouraging. The cross-sections for both positron and electron scattering are plotted for enerqies of the incoming particle ranging from 0.8eV to 6.8eV, and compared to pertinent calculations and measurements available in the literature. The present approach may result of considerable use in scattering problems involving many-electron atoms, where, as a rule, great computational difficulties must be overcome