Left-right asymmetry for scattering of polarized electrons from thallium and lead atoms

Polarized electrons were scattered elastically and inelastically from unpolarized thallium and lead atoms. The left-right scattering asymmetry has been measured for energies ranging from 2.5 to 14 eV at scattering angles between 35' and 125'. The influence of the electronic configuration of the valence electrons on the results of the asymmetry function is discussed. For elastic collisions no clear-cut conclusions about the significance of the 'fine-structure' effect compared with the Mott scattering effect can be drawn. Numerical results from R-matrix calculations show good agreement with the experimental data for thallium, whereas the theoretical predictions for lead are less satisfactory.