Population kinetics and spectral gain for relativistic hydrogen-like ions

The population kinetics and the spectral gain for the H-like Ti XXII ion are calculated allowing for the fine splitting of the levels. In the range of plasma parameters assumed in the calculations, N_e ~ (10¹²–10¹³) · Z ⁷ cm ^– 1 and T_e ~ Z ² eV, the spectral gain ϰ₄₃ is an order of magnitude greater than ϰ₄₃ for nonrelativistic ions. This is due to the characteristic features of the kinetics and due to the broadening of the lines of relativistic H-like ions.