Elastic scattering of electrons from Xe,Cs+, andBa2+

Relativistic many-body perturbation theory is applied to study the elastic scattering of electrons from xenon and from the xenonlike ions ${\mathrm{Cs}}^{+}$ and ${\mathrm{Ba}}^{2+}$, below their respective inelastic thresholds. The quasiparticle equation for the electron scattering wave function is solved in second-order perturbation theory starting from the Hartree-Fock approximation. Phase shifts for partial waves with l=0–5 are determined as functions of electron momentum for each ion. The theoretical elastic scattering cross section for xenon is found to be in agreement with experiment, showing a Ramsauer-Townsend minimum below 1 eV. Agreement with experiment is also found for differential cross sections and scattering asymmetry functions for xenon. Differential cross sections and scattering asymmetry functions for ${\mathrm{Cs}}^{+}$ and ${\mathrm{Ba}}^{2+}$ are predicted at 10 eV.