Abstract
Plane-wave Born-approximation calculations of K-shell ionization cross sections are made using one-electron Dirac and Dirac-Hartree-Fock wave functions to describe the 1s and continuum electronic orbitals. Calculations are reported for selected elements between Ca and Z=170 and for values of the ratio of the ion velocity to the K-electron velocity v1vK0.2. Simple relativistic correction factors are derived which, when multiplied by easily obtainable nonrelativistic cross sections, allow the accurate determination of relativistic K-shell ionization cross sections without having to perform further extensive calculations. The relativistic correction factors are compared with approximate correction factors discussed by Amundsen, Kocbach, and Hansteen.