Analysis of the Fourth Spectrum of Tungsten (W IV)

Abstract

The spectrum of triply ionized tungsten (W IV) was produced in a sliding-spark discharge and recorded photographically on the NBS 10.7 m normal-incidence vacuum spectrograph in the 600-2600 A spectral region. The analysis has established all 37 levels of the 5 d 3 , 5d2 6s and 5d6s2 even configurations and all 68 levels of the 5d26p and 5d6s6p odd confugurations. A total of 774 lines have been classified as transitions between these levels. Comparison of observed level values with those calculated in a least-squares fit shows an rms deviation of f 50 cm-' for the even configurations and c 250 cm-' for the odd ones.

Ionization energies of tungsten ions: W2+ through W71+

“…The fitted parameters obtained in our calculations are in good agreement with Ref. [28] for W 3+ , although the average energies could not be compared, as they were not given in Ref. [28].…”

“…[28] for W 3+ , although the average energies could not be compared, as they were not given in Ref. [28]. For W 2+ there is a significant disagreement for the average energies of the 5d 4 and 5d 3 6s configuration.…”

“…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.…”

“…In addition, the average energies of the W 3+ configurations were not given in the tables of Ref. [28]. Therefore, we made new parametric fits of the even configurations of W 2+ and W 3+ .…”

Configuration interaction and radiative decay rates in trebly ionized tungsten (W IV)

“…The first excited configurations are 5d 2 6s, 5d6s 2 , 5d 2 6p and 5d6s6p. All experimentally known energy levels are reported in the compilation of Kramida and Shirai (2009), which is essentially based on the investigations by Iglesias et al (1985) who analysed the W IV spectrum in the region of 60-260 nm using a sliding-spark discharge. These authors identified a total of 774 lines and determined all the 37 levels of the 5d 3 , 5d 2 6s and 5d6s 2 even configurations and all the 68 levels of the 5d 2 6p and 5d6s6p odd configurations.…”