ANALYSIS OF THE FOURTH SPECTRUM OF TUNGSTEN (W IV).

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 Å spectral region. The analysis has established all 37 levels of the 5d3, 5d26s 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 ± 50 cm-1 for the even configurations and ± 250 cm-1 for the odd ones.Peer Reviewe