Electron Impact Excitation and Ionization Rate Coefficients and Electron Densities Calculations for Lithium-like Ion Si XII and S XIV

Abstract

Absolute excitation and ionization rate coefficients have been evaluated for arbitrary excited states at certain electron temperatures kTe and their corresponding electron densities Ne of the Lithium‐like ions Si XII and S XIV. The populations of the chosen excited levels are calculated namely, for the doublet state of the Li‐like ions. The calculations have been carried out by using the coupled rate simultaneous equations in which, the monopole and quadruple transitions have been introduced in the calculations in addition to the dipole transitions.A theoretical population model has been developed to study the influence of the different processes that might contribute to the population of the different levels at the plasma parameters. The population densities of these different levels were then derived from these rate coefficients. For the most levels the theoretical excitation rate coefficients were found to be in good agreement with the available theoretical and experimental data. The other calculations...