Hyperfine structure and isotope shift of osmium I

Abstract

Laser induced fluorescence spectroscopy has been applied to measure the hyperfine structure and isotope shift of osmium I spectral lines in the visible range. Precise values for the hyperfine structure constants A and B of the most abundant odd mass isotope Os-189 and the level isotope shift of altogether 43 excited energy levels were determined evaluating the measurements. Osmium in its natural abundance as well as an enriched sample of Os-189 were used during the experiments. Additionally, a parametric analysis of the fine structure, the hyperfine structure and the isotope shift has been performed for the three even configurations 5d(6)6s(2), 5d(7) 6s and 5d(8). Finally, the nuclear electric quadrupole moment Q for the isotope Os-189 is determined to Q(5d(6)6s(2)) = 0.98 (8) b for the configuration 5d(6) 6s(2) and Q(5d(7)6s) = 0.97 (9) b for the configuration 5d(7) 6s.