κ distribution of carbon II doublet in the solar transition region

For accurate spectral diagnostics of the solar plasma in the transition region, the averaged collision strength of the κdistribution of electron energies is discussed for non-Maxwellian distribution, and the Maxwellian averaged collision strengths and the non-Maxwellian averaged collision strengths for κ = 2, 3 and 5 from 104.4 to 106.0 K are calculated for Carbon II doublet in the transition region. Results are in agreement with those from the CHIANTI database, and the main error comes from the approximation of the collision strength. This calculation will be significant for spectral diagnostics of the solar plasma for non-Maxwellian distribution of the electron energies.