(e,2e) measurements on xenon: Reexamination of the fine-structure effect

The process of electron scattering from heavy target atoms is of considerable interest due to the enhanced role of relativistic effects and distortion of the electron trajectories resulting from the large value of nuclear charge. Here we present e,2e ionization measurements and distorted-wave Born approximation calculations for the scattering of spin-polarized electrons from xenon atoms in which the fine-structure levels of the residual ion are resolved. Comparison of measurements performed using a high-sensitivity toroidal analyzer spectrometer with the predictions of sophisticated calculations provide an improved understanding of the ionization dynamics of heavy target atoms and the treatment of electron exchange processes.