abstract

• We have measured the hyperfine splitting of the 7P1/2 state at the 100 ppm level in Fr isotopes (Fr206g,206m,207,209,213,221) near the closed neutron shell (N=126 in Fr213). The measurements in five isotopes and a nuclear isomeric state of francium, combined with previous determinations of the 7S1/2 splittings, reveal the spatial distribution of the nuclear magnetization, i.e., the Bohr-Weisskopf effect. We compare our results with a simple shell model consisting of unpaired single valence nucleons orbiting a spherical nucleus, and find good agreement over a range of neutron-deficient isotopes (Fr207-213). Also, we find near-constant proton anomalies for several even-N isotopes. This identifies a set of Fr isotopes whose nuclear structure can be understood well enough for the extraction of weak interaction parameters from parity nonconservation studies. © 2015 American Physical Society.

authors

• Aubin S.
• Behr J.A.
• Collister R.
• Gwinner G.
• Gómez García Eduardo
• Orozco L.A.
• Pearson M.R.
• Sprouse G.D.
• Tandecki M.
• Zhang J.

publication date

• 2015-01-01

funding provided via

• National Science Foundation, NSF: 1307536  Grant

published in

• Physical Review Letters  Journal

keywords

• Atomic physics; Hyperfine splittings; Isomeric state; Neutron shells; Nuclear magnetization; Nuclear structure; Parity non-conservation; Single-particle model; Weak interactions; Isotopes

Digital Object Identifier (DOI)

• 10.1103/PhysRevLett.115.042501

start page

end page

volume

• 115

issue

• 4