Electron scattering from alkali atoms in the one-electron model

Elastic and inelastic electron scattering from H, Na and K at 54.42 eV and Li at 60 eV are calculated using the coupled-channels optical theory. The closed shells of the alkali atoms are treated as inert except for direct and exchange electron scattering. Excellent agreement with experimental data is achieved for hydrogen, indicating that the one-electron (three-body) scattering calculation is essentially correct. Correct total cross sections are achieved for the alkalis but large-angle scattering is seriously overestimated, indicating that the one-electron structure model is inadequate. The effect of configuration interaction, including core-valence correlations, is calculated for generalised oscillator strengths. It is responsible for corrections of the right order of magnitude.