THE 6TH SPECTRUM OF THALLIUM (TI-VI) - ANALYSIS OF THE 5D76S-5D76P TRANSITION ARRAY

The spectrum of thallium was photographed in the 700-1500 angstrom reg ion on 6.65 m and 3 m normal incidence spectrographs, using a sliding spark and a triggered spark as excitation source. On the basis of thes e new measurements we have established 29 levels of the 38 theoretical ly possible levels of the 5d(7)6s configuration of Tl VI. Of the 70 le vels of the 5d(7)6p configuration, given before, 68 levels have been c onfirmed, two levels have been revised and 21 new levels were establis hed. 289 lines have been classified in the 5d(7)6s-5d(7)6p transition array of Tl VI. Additional lines in the 5d8-5d(7)6p transition array a re presented. The S-1(0) level of the 5d8 configuration has been estab lished. Least-squares fitted parametric calculations were carried out and they describe the spectrum adequately.