Revised and extended analysis of the eighth spectrum of platinum (Pt VIII)

The spectrum of platinum was observed in the 300-2100 Å wavelength region. Grazing and normal incidence VUV spectrographs have been used to record the spectrum. The (5d3+5d26s)−5d26p transition array of seven times ionized platinum, Pt VIII, has been investigated. The configurations 5d3 and 5d26p had been previously studied, and all levels of these configurations (19 and 45 levels, respectively) had been established. The previous analysis was based on 178 classified spectral lines. In the current analysis we have confirmed identification of all previously found levels and all but 10 previously assigned spectral lines, although we have detected a large (up to 35 mÅ) systematic shift in wavelength measurements used in the previous analysis. Based on new wavelength measurements, we have corrected the 5d3 and 5d26p energy level values (by up to 55 cm−1) and established for the first time 14 out of 16 theoretically possible 5d26s levels in Pt VIII. The total list of identified lines (including 180 new lines) contains 349 entries. The orthogonal operators technique was used to calculate the level structure and transition probabilities. The energy parameters have been determined by the least squares fit to the observed levels. Calculated transition probability and energy values, as well as LS-compositions obtained from the fitted parameters are presented.