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The changes in the mean-square charge radius (relative to 209Bi), magnetic dipole, and electric quadrupole moments of 187,188,189,191Bi were measured using the in-source resonance-ionization spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in 187,188,189Big, manifested by a sharp radius increase for the ground state of 188Bi relative to the neighboring 187,189Big. A large isomer shift was also observed for 188Bim. Both effects happen at the same neutron number, N=105, where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were identified by the blocked quasiparticle configuration compatible with the observed spin, parity, and magnetic moment. ispartof: Physical Review Letters vol:127 issue:9 ispartof: location:United States status: published

This work is devoted to investigations of unclassified spectral lines in atomic holmium, aiming at identification of new electronic levels and determination of their hyperfine structure. Altogether 113 unclassified lines were investigated with the method of laser induced fluorescence in a hollow cathode discharge lamp. As a result, 35 odd-parity electronic levels with previously unknown energies were identified; for all of them the hyperfine structure constants A and B were also determined. The data reported greatly facilitated the semi-empirical fit of the fine and hyperfine structure of the odd-parity level system, performed in our group.

In this work investigations of the hyperfine structure of 66 spectral lines of the holmium atom were performed with the method of laser induced fluorescence in a hollow cathode discharge lamp. Altogether 43 odd-parity levels, involved as the upper levels in the transitions studied, were investigated. For about half of them the hfs constants A and B were evaluated for the first time. For some levels, already examined in earlier works, supplementary results were obtained; for a few levels it was possible to compare our results with earlier literature data. For 4 levels J quantum numbers were changed with respect to the available literature values. As a by-product, also improved hfs constants for the lower even-parity levels were determined. The data reported facilitated the semi-empirical fit of the fine and hyperfine structure of the odd-parity level system, performed in our group.

In this work the hyperfine structure of some tens of unclassified spectral lines in the holmium atom was investigated with the method of laser induced fluorescence in a hollow cathode discharge lamp. As a result, 21 new electronic odd-parity levels, with previously unknown energies within the range 33000–42000 cm − 1 , were identified and their hyperfine structure constants A and B were determined. The experimental data obtained will facilitate the semi-empirical fit of the fine and hyperfine structure of the odd-parity level system for the atomic holmium, currently in progress in our group.

Semi–empirical analyses of the fine– and hyperfine structure for both parities of atomic and ionic bismuth were conducted in a multiconfiguration approach. Four sets of independent hyperfine structure (hfs) radial parameters were determined by means of a many–body parametrization method. The Sternheimer free value of the nuclear quadrupole moment (Q) of 209 Bi was determined. Four sets of independently derived hfs radial parameters led to consistent Q values.

In the present work measurements of Lande gJ factors for some electronic levels of the europium atom are presented. The measurements were performed with the use of the Zeeman effect of the hyperfine structure, observed with the method of laser spectroscopy in a hollow cathode discharge lamp placed in constant magnetic field, with laser induced fluorescence detection. Investigation of 54 spectral lines of europium in the spectral range 511–662 nm enabled for the first time the determination of gJ factors for 16 levels belonging to the odd-parity configurations of Eu and 4 levels belonging to the even-parity configurations. Moreover, 3 gJ values for levels belonging to the even-parity configurations, previously known from the literature, were corrected.

In this work a semi-empirical analysis of the odd configurations system of atomic tin is presented. A multiconfiguration parametric calculation on the basis of 184 configurations have been performed by taking into account the second-order of the perturbation theory. Satisfactory consistency of the values of experimental and calculated energy levels and Lande g J was found. The eigenvector amplitudes were used for the parametrization of radiative transitions from odd to even levels. The radiative lifetimes of the selected odd levels were determined. The results were compared with available experimental data and theoretical calculations.

This work presents the measurements of the hyperfine structure constants A and B, as well as the isotope shifts, for 26 electronic levels belonging to the even-parity configurations at the energy range 28000–40000 cm − 1 in the europium atom. The measurements were performed with the use of laser spectroscopy with a hollow cathode discharge lamp as the source of the atoms and the detection of laser induced fluorescence. Among the results obtained, 10 levels were measured for the first time, in the case of another 3 levels results somewhat more precise than the earlier published ones were obtained. The A and B hyperfine structure constants’ values were determined on the basis of the measurements on 73 spectral lines located in two wavelength ranges: 480–560 nm and 625–680 nm.

In this work laser-spectroscopic investigations of selected electronic levels in the holmium atom are performed in the context of possible second-stage laser cooling transitions which can be considered in a magneto-optical trap. Five transitions were directly recorded by the method of laser induced fluorescence in a hollow cathode discharge. The hyperfine structure constants A and B for the upper even-parity J = 17 / 2 levels, evaluated in earlier works, were generally confirmed, and their accuracy was improved; thus the frequency differences between the hyperfine structure components, relevant for the possibility of application of the hyperfine repumping, could be determined. Investigations of the Zeeman-hyperfine structure of these spectral lines were performed in order to evaluate the Lande gJ factors of the upper levels; these were reported for the first time. Semi-empirical preliminary calculations of the lifetimes of the even-parity levels in question were also carried out, allowing estimation of the expected Doppler limits for the possible narrow-band laser cooling at the respective transitions. The degree of similarity between the gJ factors of the upper levels of the cooling transitions and the ground state is important for the efficiency of the sub-Doppler laser cooling in a magneto-optical trap. The results presented might facilitate the choice of the most favorable option of obtaining narrow-band laser cooling of the holmium atoms.

In this work the hyperfine structure of 43 odd-parity levels of the terbium atom was investigated with the method of laser induced fluorescence in a hollow cathode discharge. Altogether 73 spectral lines were examined, with the odd-parity levels involved as the upper levels. For 41 levels the constants A and B were determined for the first time, and for the remaining two levels improved values could be obtained due to the supplementary measurements performed. As a by-product, also the hyperfine structure constants for two lower even-parity levels could be corrected. The obtained results concerning the odd-parity levels contributed to considerable extension of the available database of the hyperfine structure constants for the atomic terbium; they would be included in the semi-empirical analysis of the fine and the hyperfine structure for the odd-parity configurations system, planned in our research group.