Theoretical Electron- Impact Excitation, Ionization and Recombination Rate Coefficients and Level Population Densities for Scandium-Like Ion

Absolute excitation, ionization and recombination rate coefficients for 22 levels have been evaluated from our experimental results at different Plasma temperatures for excited atomic states in Ti II. The corresponding electron densities are determined to calculate the populations of the 22 excited levels belonging to 3d³, 3d²4s and 3d²4p, namely for doublet and quartet states. The calculations have been carried out by using the coupled rate simultaneous equations in which the monopole and the quadrupole 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 our plasma parameters. The population densities for the 22 different levels were then derived from these rate coefficients. It is found that, the highest value of the population densities is for the 3d³ (⁴F) excited level and the lowest value is for the 4p (²P) excited level.