isomer

[paper] Magnetic moment of the 13/2+ isomeric state in 69Cu: Spin alignment in the one-nucleon removal reaction

Magnetic moment of the 13/2+ isomeric state in 69Cu: Spin alignment in the one-nucleon removal reaction

A. Kusoglu et al.

doi: http://dx.doi.org/10.1103/PhysRevC.93.054313

We report on a new measurement of the g factor of the (13/2+) isomeric state in the neutron-rich nucleus 69Cu. This study demonstrates the possibility of obtaining considerable nuclear spin alignment for multi-quasiparticle states in single-nucleon removal reactions. The time-dependent perturbed angular distribution (TDPAD) method was used to extract the gyromagnetic factor of the (13/2+) [T½=351(14) ns] isomeric state of 69Cu. Its g factor was obtained as g(13/2+)=0.248(9). The experimentally observed spin alignment for the state of interest was deduced as A=−3.3(9)%.

[paper] Hyperfine structure anomaly and magnetic moments of neutron deficient Tl isomers with I=9/2

Hyperfine structure anomaly and magnetic moments of neutron deficient Tl isomers with I=9/2

A.E. Barzakh et al.

doi: 10.1103/PhysRevC.86.014311

The hyperfine structure of 276.9-nm atomic transition has been studied by the resonant ionization spectroscopy method at mass-separator IRIS (Investigation of Radioactive Isotopes on Synchrocyclotron), Petersburg Nuclear Physics Institute (PNPI) for the odd Tl isomers with I=9/2 and A=187–197. A differential hyperfine structure anomaly for 6p2P1/2 and 7s2S1/2 atomic states in Tl isomers with I=9/2 has been determined. It is described by the recently developed theoretical approach fairly well. This enables one to recalculate the magnetic moments of 187−193Tlm(I=9/2) from previously measured hyperfine splittings for 7s2S1/2 states and to determine for the first time the magnetic moments for 197Tlm and 195Tlm(I=9/2) from hyperfine splittings for 6p2P1/2 states with properly taking into account the rather great hyperfine structure anomaly. Similar measurements with greater accuracy have been proposed for the other nuclear states in odd-odd Tl isotopes. These measurements could shed light on the nuclear magnetization distribution in these isotopes.

[paper] Is the 7/21 Isomer State of 43S Spherical?

Is the 7/21 Isomer State of 43S Spherical?

R. Chevrier et al.

doi: 10.1103/PhysRevLett.108.162501

We report on the spectroscopic quadrupole moment measurement of the 7/21 isomeric state in 4316S27 [E*=320.5(5)  keV, T1/2=415(3)  ns], using the time dependent perturbed angular distribution technique at the RIKEN RIBF facility. Our value, ∣Qs∣=23(3)  efm2, is larger than that expected for a single-particle state. Shell model calculations using the modern SDPF-U interaction for this mass region reproduce remarkably well the measured ∣Qs∣, and show that non-negligible correlations drive the isomeric state away from a purely spherical shape.

[paper] Wigner Crystals of 229Th for Optical Excitation of the Nuclear Isomer

Wigner Crystals of 229Th for Optical Excitation of the Nuclear Isomer

C.J. Campbell et al.

doi: 10.1103/PhysRevLett.106.223001

We have produced laser-cooled Wigner crystals of 229Th3+ in a linear Paul trap. The magnetic dipole (A) and electric quadrupole (B) hyperfine constants for four low-lying electronic levels and the relative isotope shifts with respect to 232Th3+ for three low-lying optical transitions are measured. Using the hyperfine B constants in conjunction with prior atomic structure calculations, a new value of the spectroscopic nuclear electric quadrupole moment Q=3.11(16)  eb is deduced. These results are a step towards optical excitation of the low-lying isomer level in the 229Th nucleus.