Fully relativistic electron-impact ionization of atomic ions

A fully relativistic electron-impact ionization cross section is calculated as a triple partial-wave expansion of the first Born scattering amplitude. The target atomic ion is described by a Dirac-Fock approximation, a jj subconfiguration average method is used to calculate the scattering algebra, and the radial partial waves (ɛlj) are computed in distorted-wave potentials. The resulting general computational scheme is applied to electron-impact ionization of ${\mathrm{U}}^{89+}$. The fully relativistic cross-section results are compared with those obtained from both nonrelativistic and semirelativistic theories.