Electron-impact collision strengths for inner-shell excitation of doubly excited levels from singly excited levels in He-like ions

The simple Coulomb-Born-Exchange method has been used to calculate electron-impact collision strengths for inner-shell excitation of the doubly excited levels with n = 2 in He-like ions from the singly excited levels. The results are of particular interest for plasma diagnostic purposes. The calculations were made for nine impact electron energies in threshold units epsilon = 1.0, 1.2, 1.5, 1.9, 2.5, 4.0, 6.0, 10.0 and 15.0 for 19 He-like ions with nuclear charge number Z in the range 6> or =Z> or =74. Fits are given of the scaled collisions strength Z2Ω to simple functions of epsilon that are readily integrated over a Maxwellian distribution to obtain collision rates. Configuration-interaction and intermediate-coupling effects have been included in the calculations. Calculated values for transition energies and radiative line strengths are also given