He-like ions (Z=20-42) effective collision strengths

A reliable plasma modeling and interpretation of the spectra require a large amount of accurate atomic data related to various physical processes. In this paper, we focus on the electron-impact excitation (EIE) process.

We adopted the independent process and isolated resonances approximation using distorted waves (IPIRDW). Resonant stabilizing transitions and decays to lower-lying autoionizing levels from the resonances are included as radiative damping. To verify the applicability of the IPIRDW approximation, an independent Dirac R-matrix calculation was also performed.