Effects of dynamical screening on single ionization of sodium by electron impact in doubly symmetric geometry

Abstract

A dynamically screened three-Coulomb-wave model (DS3C) is applied to study the single ionization of sodium by electron impact. Triply differential cross sections (TDCS) are calculated in doubly symmetric geometry at excess energies of 6, 10, 15, 20, 30, 40, 50, and 60 eV. Comparisons are made among DS3C and the latest experimental data and such theoretical predictions as the three--Coulomb--wave function approach, the distorted-wave Born approximation, and the nonperturbative convergent close-coupling method. The angular distribution and relative magnitude of the present TDCS are found to qualitatively reproduce the reported experimental data. It is shown that dynamically screened effects are important in the geometries studied here.