Transitions from the configurations involving 4f-electrons in Cs IX - La XI and Cs XI - Ce XIV spectra

Abstract

The 4d 9 -4d 8 4f transitions in Rh I-like ions from Cs XI to Ce XIV have been identified. Two lines, the 4d 10 5s 2 S-4d 9 5s4f 2 P transitions, in Cs IX to La XI have also been identified. In the La IX spectrum the 4d 10 4f 2 F and 4d 10 8p 2 P levels have also been established. Predictions for the corresponding transitions in Xe VIII and Xe X are also given.

Ground-state configurations and unresolved transition arrays in extreme ultraviolet spectra of lanthanide ions

“…Currently ground configurations of the lanthanides are known experimentally for ion stages up to the third, and fourth in some cases [2]. As noted in [1], systematic analysis of spectra in higher ion stages of lanthanum and cerium have been performed: La VII [9], La XI [10,11], La XIII [12], Ce III [13], Ce V [14], Ce VI [15], Ce IX [16], Ce X [17] and Ce XIV [10][11][12]. More recently progress has been made in analysing Cd-like ion spectra from Xe VII -Eu XVI [5, 18,19] and Pd-like ion spectra [20].…”

4p64d8–(4d75p + 4d74f + 4p54d9) Transitions in Xe XI

“…Sugar [24]. The 4d 10 4f energies for Xe VIII are taken from Larsson et al [25], for Ba X from Churilov and Joshi [26], and for La XI from Gayasov and Joshi [27]. Ionization energies for I VII, Cs IX, Ba X, and La XI are from Kaufman and Sugar [24].…”

Extended analysis of the Ba XII spectrum in the EUV region

“…the ratios of the semi-empirical (least-squares-fitted (LSF)) parameters to the HFR radial integrals. The Ba XII lines already classified in [1,2] were predicted by this extrapolation with an accuracy better than 0.1 Å. The parameters of the other unknown configurations were fixed at their Hartree-Fock (HF) values (average energies and spin-orbit parameters) or at 0.85 of their HF values (Coulomb and configuration interaction parameters).…”

“…They established the fine structure splitting of 4d 9 2 D ground term through eight pairs of lines as 22060 ± 20 cm −1 , and derived the energies of 32 out of 45 possible 4d 8 5p levels. Later, Gayasov and Joshi classified six lines in the 97-100 Å region as the strongest transitions from the strongly interacting 4d 8 4f and 4p 5 4d 10 configurations in Ba XII [2].…”