0000000000496425
AUTHOR
C. D. P. Levy
High precision measurement of the11Li and9Li quadrupole moment ratio using zero-fieldβ-NQR
The ratio of electric quadrupole moments of 11 Li and 9 Li was measured using the zero-field β-detected nuclear quadrupole resonance technique at TRIUMFISAC. The precision on the ratio Q11/Q9 = 1.0775(12) was improved by more than one order of magnitude and an absolute value for the quadrupole moment of 11 Li was inferred. Systematic effects, as argued here, are not expected to contribute to the ratio on this scale. The zero-field spin-lattice relaxation time for 8 Li implanted within SrTiO3 at 295K in zero-field was found to be T1 = 1.73(2)s. A comparison of the quadrupole moments of 9,11 Li and their ratio is made with the latest models, however, no conclusion may yet be drawn owing to th…
Tests of atomic charge-exchange cells for collinear laser spectroscopy
Abstract The performance characteristics of two charge-exchange cells (CECs) with horizontal and vertical cell configurations were determined by neutralizing a 10-keV rubidium ion beam in a potassium vapor. The neutralization efficiency and the fluorescence line shape of the 5s 2 S 1 / 2 ↔ 5 p 2P3/2 (D2) transition in neutral 85Rb were investigated as a function of the reservoir temperature used to control the potassium vapor density. The CECs exhibited similar neutralization performance and at neutralization efficiencies greater than 25–50% an asymmetric line shape of the rubidium D2 fluorescent signal was observed. The asymmetry was attributed to inelastic channels in the charge-exchange …
Nuclear moments and charge radii of neutron-deficient francium isotopes and isomers
Collinear laser fluorescence spectroscopy has been performed on the ground and isomeric states of 204,206Fr in order to determine their spins, nuclear moments, and changes in mean-squared charge radii. A new experimental technique has been developed as part of this work which much enhances the data collection rate while maintaining the high resolution. This has permitted the extension of this study to the two isomeric states in each nucleus. The investigation of nuclear g factors and mean-squared charge radii indicates that the neutron-deficient Fr isotopes lie in a transitional region from spherical towards more collective structures. peerReviewed
Isotope-shift measurements of stable and short-lived lithium isotopes for nuclear-charge-radii determination
Changes in the mean-square nuclear charge radii along the lithium isotopic chain were determined using a combination of precise isotope shift measurements and theoretical atomic structure calculations. Nuclear charge radii of light elements are of high interest due to the appearance of the nuclear halo phenomenon in this region of the nuclear chart. During the past years we have developed a new laser spectroscopic approach to determine the charge radii of lithium isotopes which combines high sensitivity, speed, and accuracy to measure the extremely small field shift of an 8 ms lifetime isotope with production rates on the order of only 10,000 atoms/s. The method was applied to all bound iso…
Nuclear moments and charge radii of neutron-deficient francium isotopes and isomers
Collinear laser fluorescence spectroscopy has been performed on the ground and isomeric states of $^{204,206}\mathrm{Fr}$ in order to determine their spins, nuclear moments, and changes in mean-squared charge radii. A new experimental technique has been developed as part of this work which much enhances the data collection rate while maintaining the high resolution. This has permitted the extension of this study to the two isomeric states in each nucleus. The investigation of nuclear $g$ factors and mean-squared charge radii indicates that the neutron-deficient Fr isotopes lie in a transitional region from spherical towards more collective structures.