Electron excitation of the 1s²2s²2p⁵²P^o_3/2-²P^o_1/2transition and analysis of the 1s²2s2p⁶nl resonances for Ne II and Mg IV

Abstract

The author has calculated collision strengths for electron excitation of the 1s22s22p5 2Po3/2-2Po1/2 transition in Ne II and Mg IV using the R-matrix method. The author has included the 1s22s22p5 2Po and 1s22s2p6 2Se states, which were represented by sophisticated configuration interaction wavefunctions. Reactance matrices were obtained in LS coupling and transformed using JAJOM to give the fine-structure collision strengths. These have been averaged over a Maxwellian electron velocity distribution to give the effective collision strengths, which we have fitted as analytic functions of temperature between 0 and 40000 K. To estimate the accuracy of the results the author has calculated the positions and widths for the lower members of the 1s22s2p6ns and 1s22s2p6np resonance series. The results are in good agreement with experiment and with previous theory for both Ne II and Mg IV.