DEEXCITATION AND RECOMBINATION OF EXCITED IONS THROUGH DOUBLY-EXCITEDLEVELS IN A DENSE RECOMBINING PLASMA - LITHIUM-LIKE RECOMBINING PLASMA LASER

Collisional transitions from excited levels in a dense recombining pla sma have been considered for lithiumlike ions. Deexcitation from a lev el of the lithiumlike ion is enhanced by a process in which berylliuml ike ions in doubly excited levels in local thermodynamic equilibrium w ith respect to this level autoionize. Excited ions may recombine throu gh a process similar to the collisional-radiative (CR) recombination a s in the case of ions in their ground states. We have estimated the ef fective rate coefficients for these processes by adopting various appr oximations. We have incorporated these approximations into our CR mode l code for lithiumlike aluminum ions in a high-density recombining pla sma. The excited level populations and the amplification gains of seve ral laser transitions are calculated for typical conditions of the rec ombining plasma laser. For an electron temperature of 5 eV, the gains of the 3d D-2-5f F-2 and 3d D-2-4f F-2 transitions are consistent with the experimental results.