Using the generalized oscillator-strength formulation of the Born approximation, electron ionization cross sections were calculated for 20 elements with $19\le Z\le 54$. For Kr and Xe, good agreement (30%) is found for the total ionization cross section above 300 eV. Comparison with measured cross sections for producing various charge states in Kr and Xe showed significant discrepancies, which arise from neglect of configuration interaction. Comparison with measured total cross sections for other elements show limited agreement, though the agreement improves as one goes to higher $Z$.

• Received 25 February 1977

DOI:https://doi.org/10.1103/PhysRevA.16.62