charge radii

[paper] Onset of deformation in neutron-deficient Bi isotopes studied by laser spectroscopy

Onset of deformation in neutron-deficient Bi isotopes studied by laser spectroscopy

A.E. Barzakh et al.

In-source laser spectroscopy experiments for bismuth isotopes at the 306.77-nm atomic transition has been carried out at the Investigation of Radioactive Isotopes on Synchrocyclotron facility of Petersburg Nuclear Physics Institute. New data on isotope shifts and hyperfine structure for Bi ground states and isomers (^{189,190m1,190m2,191,192,192m,194,194m,198m}Bi) have been obtained. The changes in the mean-square charge radii δ⟨r²⟩ and magnetic-moment values have been deduced. For Bi nuclei a marked deviation from the isotopic trend of δ⟨r²⟩ in lead and thallium isotopic chains has been demonstrated at N<111. This has been interpreted as an indication of the onset of quadrupole deformation. Analysis of the magnetic moments for odd-odd Bi isotopes also points to the possible increase in deformation at N<111.

Apr 30, 2017 by Theo experiment g factor radii 0

[paper] Isomer Shift and Magnetic Moment of the Long-Lived ½⁺ Isomer in ⁷⁹Zn: Signature of Shape Coexistence near ⁷⁸Ni

Isomer Shift and Magnetic Moment of the Long-Lived ½⁺ Isomer in ⁷⁹Zn: Signature of Shape Coexistence near ⁷⁸Ni

X.F. Yang et al.

doi: 10.1103/PhysRevLett.116.182502

Collinear laser spectroscopy is performed on the ⁷⁹Zn isotope at ISOLDE-CERN. The existence of a long-lived isomer with a few hundred milliseconds half-life is confirmed, and the nuclear spins and moments of the ground and isomeric states in ⁷⁹Zn, as well as the isomer shift are measured. From the observed hyperfine structures, spins I=9/2 and I=½ are firmly assigned to the ground and isomeric states. The magnetic moment μ(⁷⁹Zn)=-1.1866(10)μ_N, confirms the spin-parity I=9/2⁺ with a νg_9/2^-1 shell-model configuration, in excellent agreement with the prediction from large scale shell-model theories. The magnetic moment μ(^79mZn)=-1.0180(12)μ_N supports a positive parity for the isomer, with a wave function dominated by a 2h-1p neutron excitation across the N=50 shell gap. The large isomer shift reveals an increase of the intruder isomer mean square charge radius with respect to that of the ground state, δ2>^79,79m=+0.204(6) fm², providing first evidence of shape coexistence.

May 16, 2016 by Theo g factor 0

[Conference paper] Physics highlights from laser spectroscopy at the IGISOL

Physics highlights from laser spectroscopy at the IGISOL

D.H. Forest and B. Cheal

doi: 10.1007/s10751-012-0620-9

Laser spectroscopy provides model-independent access to a variety of radioactive nuclear ground state and isomeric state properties. These include the nuclear moments, changes in mean-square charge radii, and direct measurements of the nuclear spin. At the IGISOL laboratory, the collinear laser spectroscopy programme is able to access cases, such as refractory elements and short-lived states, not available at conventional facilities. A summary of physics highlights is presented here.

Mar 30, 2012 by Theo g factor 0

[paper] Charge radii and electromagnetic moments of Li and Be isotopes from the ab initio no-core shell model

Charge radii and electromagnetic moments of Li and Be isotopes from the ab initio no-core shell model

C. Forssén et al.

Recently, charge radii and ground-state electromagnetic moments of Li and Be isotopes were measured precisely. We have performed large-scale ab initio no-core shell model calculations for these isotopes using high-precision nucleon-nucleon potentials. The isotopic trends of our computed charge radii and quadrupole and magnetic-dipole moments are in good agreement with experimental results with the exception of the ¹¹Li charge radius. The magnetic moments are in particular well described, whereas the absolute magnitudes of the quadrupole moments are about 10% too small. The small magnitude of the ⁶Li quadrupole moment is reproduced, and with the CD-Bonn NN potential, also its correct sign.

Feb 25, 2009 by Theo theory 0

Blogroll

Tags