The spectrum of doubly ionized tungsten (W-III)

Abstract

The spectrum of doubly ionized tungsten (W III) was produced in a sliding-spark discharge and recorded photographically on the NIST 10.7-m normal-incidence vacuum spectrograph in the 600–2680 Å spectral region. The analysis has led to the establishment of 71 levels of the interacting 5d4, 5d3 6s and 5d2 6s2 even configurations and 164 levels of the interacting 5d3 6p and 5d2 6s 6p odd ones. A total of 2636 lines have been classified as transitions between the 235 experimentally determined levels. Comparison between the observed levels and those calculated from matrix diagonalizations with least-squares fitted parameters shows an rms deviation of ±87 cm−1 for the even configurations and ±450 cm−1 for the odd ones.

Ionization energies of tungsten ions: W2+ through W71+

“…Our fitted value of E av (5d 3 6s) is lower than that given in Ref. [27] by 4500 cm À1 , while E av (5d 4 ) is higher by 2700 cm À1 . The W 4+ spectrum was analyzed by Meijer [29], Churilov et al [20], and Kildiyarova et al [30].…”

“…Although the analyses of W 2+ and W 3+ done by Iglesias et al [27,28] included parametric fits, they did not include some configurations that significantly shift the average energies of interest. In addition, the average energies of the W 3+ configurations were not given in the tables of Ref.…”

Energy levels of singly-ionized platinum

“…The spectrum of Pt III is still unknown but, for application to Pt II, its low energy levels can be predicted by means of the Slater-Condon method. By comparing the lowest energy levels of 5d N , 5 d N −1 6 s and 5 d N −2 6 s 2 in Hf III ( N = 2) [ 6 ], W III ( N = 4) [ 7 ], Au III ( N = 9) [ 8 ] and Hg III ( N = 10) [ 9 ], one can reasonably assume that the excitation energies of 5d 7 6 s 5 F 5 and 5d 6 6 s 2 5 F 5 and 5 d 6 6 s 2 5 D 4 levels above the ground level 5 d 8 3 F 4 are about 20000 and 60000 cm −1 , respectively. All other parameters needed for describing (5 d +6 s ) 8 in Pt III may be obtained from regular trends investigated in second spectra [ 3 ] and in third spectra.…”

Lifetime measurements and calculated transition probabilities in W III

“…The HFR + CP method was then combined with LSF routine minimizing the discrepancies between the calculated energies and the experimental values published by Iglesias et al [22]. All the 235 experimentally known energy levels were included in the fitting process.…”

“…The only term analysis of W III that has been published is due to Iglesias et al [22]. These authors classified 2636 lines between 60 and 268 nm connecting 235 atomic energy levels.…”