Ionisation from the 3p and 3d sublevels of highly charged ions

Coulomb-Born-exchange calculations of the scaled cross sections for ionisation from the 3p and 3d sublevels of hydrogenic ions in the limit Z to infinity are made for eight impact electron energies. In addition, similar calculations are made for ionisation from the lower sublevels considered in earlier work (see ibid., vol.11, p.3235 (1978)). The results are fitted to a simple form which is readily integrated over a Maxwellian distribution function to obtain collisional ionisation rates. The results can be easily used to obtain approximate results for ionisation from the 3d and all lower sublevels of highly charged complex ions with finite Z. Results obtained in this way agree well with the Coulomb-Born-exchange results of Rudge and Schwartz (1966) obtained using the Hartree-Fock target wavefunctions.