Fine Structure Effect in Electron Impact Ionization

Abstract

Spin resolved (e,2e) experiments provide an extremely sensitive test of theories of electron impact ionization and many-body Coulomb effects. We present here results for (e,2e) collisions with xenon which show the first experimental evidence of the fine structure effect in electron impact ionization, analogous to the well known effect in electron impact excitation of atoms by polarized electrons. Comparison with distorted-wave Born-approximation calculations shows the sensitivity of the results to details of the target atom wave functions as well as the treatment of relativistic effects.