Spectra and energy levels of three- and four-times ionized hafnium (Hf iv and Hf v)

Abstract

The spectra of hafnium produced by a sliding-spark discharge operating at peak currents of 6 to 1200 Å were photographed in the spectral range of 400 to 2100 Å. Sixty-three lines of Hf iv were measured in the limited range of ~ 500–900 Å, of which 43 were classified. New levels in the 4f14nl doublet term system of Hf iv were found for nl = 6f, 7p, and 8s. In addition, the resonance transition array 4f145d–4f135d2 was interpreted. In Hf v 216 lines were observed. With these data, all levels of the configurations 4f13nl for nl = 6s, 7s, 6p, 5d, and 6d were found except for two levels of 4f136d. Theoretical interpretations are given of all of the above configurations. Values for the ionization energies of both species were derived.