Population kinetics of lithiumlike ions in plasma

For lithiumlike ions (oxygen and aluminum), characteristics of the population distribution over the excited levels and the population kinetics are examined in detail. In the high-density region, a simple approximate distribution function is derived for both the ionizing and recombining plasma components on the basis of the multistep ladderlike excitation or deexcitation mechanism, combined with the thermodynamic equilibrium distribution. As examples of applications, we present intensity ratios of emission lines from impurity ions in hydrogen plasma, and the population inversion and gain for the x-ray recombining plasma laser