Abstract

This paper focuses on three topics: identification of n = 3−3 transitions observed in the emission spectra of Se, Y, and Mo, calculation of electron collision strengths for n = 2−3 transitions, and the effect of dielectronic recombination on the kinetics of neonlike lasers. We have used a semiempirical procedure, based on relativistic, multi-configurational calculations of energy levels and previous experimental data for Z ≤ 26, to identify the n = 3−3 emission lines of Se²⁴⁺, Y²⁹⁺, and Mo³²⁺ in XUV spectra obtained in different irradiation conditions. Some magnesium-like and fluorinelike transitions have also been found. Since the primary pumping mechanism for the unexpectedly weak j = 0−1 laser line is electron collisional excitation from the neonlike ground state, we have compared the excitation cross sections calculated with several different distorted wave codes and examined the effects of resonance contributions due to sodiumlike doubly excited states. We have included detailed dielectronic recombination rates, calculated with a multiconfigurational Dirac-Fock method,¹ in a simple kinetic model for neonlike lasers and found that this process is an important mechanism for populating the j = 2 upper laser levels when the density of fluorinelike ions is relatively large.²

© 1986 Optical Society of America