Excitation rates for optically allowed transitions among degenerate levels of H-like ions with 2≤Z≤30

Abstract

Using the Coulomb-Born approximation, collision strengths and effective collision strengths (excitation rates) are calculated for optically allowed transitions among degenerate levels of H-like ions with 2 ≤ Z ≤ 30 and n ≤ 5. Collision strengths are calculated over a wide range of energies up to Ej/Z2 = 10 Ryd. Effective collision strengths are obtained over a wide temperature range up to 108 K by integrating the collision strengths over a Maxwellian distribution of electron velocities.