The 4<i>d</i>⁹5<i>p</i> transitions in the tenth spectrum of cesium, Cs X

The spectrum of cesium was photographed in the 850–400 Å (1 Å = 10−10 m) wavelength region. Nineteen lines were interpreted as transitions between the 4d95s and 4d95p configurations. All levels of the 4d10, 4d95s, and 4d95p configurations were established. Least-squares-fitted parametric calculations and Hartree–Fock ab initio calculations support the analyses. </jats:p

The 5<i>s</i>²5<i>p</i>² − (5<i>s</i>²5<i>p</i>5<i>d</i> + 5<i>s</i>5<i>p</i>³ + 5<i>s</i>²5<i>p</i>6<i>s</i> + 5<i>s</i>²5<i>p</i>7<i>s</i>) transitions in Sb II and 5<i>s</i>²5<i>p</i> − (5<i>s</i>5<i>p</i>² + 5<i>s</i>²<i>nl</i>) transitions in Sb III

The spectrum of antimony was photographed in the 575–2300 Å region (1Å = 10−10 m) using a hollow cathode and a triggered spark source. The analysis of the 5s25p2 − (5s25p5d + 5s5p3 + 5s25p6s + 5s25p7s) transitions in Sb II spectrum was revised and interpreted on the basis of multiconfiguration interaction calculations. Accurate wavelength measurements of Sb III lines lead to a revised ground-state 5s25p2P interval value of 6574.5 cm−1. </jats:p

Progress in the analysis of the even parity configurations of tantalum atom

The experimental work of L. Windholz, G.H. Guthöhrlein and co-workers, concerning observation of the tantalum spectrum, yield many information about new energy levels and hyperfine structure splitting. We contribute the results of the complex parametric studies of the fine- and hyperfine structure of the mentioned element up to second-order of perturbation theory, including the effects of closed shell - open shell excitations. The work has been performed for the systems including 47 even configurations. The values of the radial parameters describing the one- and many-body interactions effects on atomic structure are given. We predicted values of energy levels and their A- and B- hyperfine structure constants, also for experimentally levels not observed up to now

Investigation of the hyperfine structure of Ta I lines (V)

We report on further investigations of the hyperfine structure of spectral lines of the neutral tantalum atom. Besides determination of the hyperfine constants A and B of 21 levels we report on the discovery of 9 up to now unknown fine structure levels for which we could determine their energy position, parity, angular momentum and the constants A and B. For a large number of up to now unclassified lines the combinations could be identified

Hyperfine splitting and isotope shift in the optical transition

The laser-induced resonance fluorescence in an atomic beam was used in order to measure the hyperfine splitting of the 4ƒ76s2 8S7/2 and 4ƒ76s6p 6P5/2 levels in 151,153,155 Eu isotopes. The hfs constants A and B of the unstable 155Eu were determined for the first time: Aexp(155,8S7/2) = -8.78(3) MHz, Aexp(155,6P5/2) = -261.68(11) MHz and Bexp(155, 6P5/2) = -941(1) MHz. With these data and after corrections for second-order hyperfine structure perturbations the nuclear moments of 155Eu were deduced: μ(155) = 1.520(2) n.m. and Qs(155) = 2.494(20) b. In addition new and more precise values of the hfs constants of the excited state for the stable 151,153Eu were obtained. They are as follows: Aexp(151, 6P5/2 = -591.92(9) MHz, Bexp(151, 6P5/2) = -354.58(97) MHz and Aexp(153, 6P5/2) = -263.19(8) MHz, Bexp(153, 6P5/2) = -922.07(79) MHz. The hyperfine anomalies 151Δ153 = 0.74(4)% and 153Δ155 = 0.27(34)% were extracted from the corrected hfs constants