Doubly differential cross sections for ionization of xenon by spin-polarized electrons

Abstract

Even though spin-dependent effects are naturally associated with relativistic effects, it has been known for some time that significant spin asymmetries for electron-impact ionization are possible in a completely non-relativistic model if the J-state of the residual ion can be experimentally resolved. In the lowest order implementation of the same model, the spin asymmetry would vanish if the J-states of the ion are not experimentally resolved (i.e., summed over). Consequently, it is perhaps possible to search for relativistic effects by looking at asymmetries for which the final ion J-state is not resolved. There is also some experimental evidence that relativistic effects might be important for large scattering angles which are inaccessible to current experimental set-ups. If this is the case, relativistic effects might be seen in a double differential cross section measurement which integrates over all angles. Very recently, some significant experimental spin asymmetries for electron–xenon scattering have been reported for a doubly differential spin-asymmetry measurement in which the final J-state was not resolved. The purpose of this paper is to investigate whether or not these experimental results indicate relativistic effects.