PHOTOIONIZATION OF ATOMIC BISMUTH

The vacuum ultraviolet photoionization spectrum of atomic bismuth, cov ering the region from ionization threshold to 740 Angstrom, is reporte d. Comparison with prior photographic absorption studies from threshol d to similar to 1320 Angstrom (encompassing the P-3(0)-P-3(2) energies of Bi+) indicates saturation of intense autoionization features in th e densitometer traces. Although fluorescence has been observed corresp onding to many of these peaks, their widths imply that autoionization is dominant. Consequently, estimates of the oscillator strengths can b e made from the photoionization spectrum. The peak widths and profiles differ from those in arsenic and antimony, probably due to significan t departure from LS coupling. New series are observed, involving excit ation of the inner valence 6s orbital, and converging to Bi+, S-5(2). They are interpreted with the aid of relativistic ab initio calculatio ns.