The transient-field technique has been used in both conventional kinematics and inverse kinematics to measure the g factors of the 2 + 1 states in the stable even isotopes of Ru, Pd and Cd. The statistical precision of the g(2 + 1 ) values has been significantly improved, allowing a critical comparison with the tidal-wave version of the cranking model recently proposed for transitional nuclei in this region.

The emergence and evolution of collective excitations in complex nuclei remains a central problem in the quest to understand the nuclear many-body problem. Nuclear quadrupole collectivity is usually investigated via electric quadrupole observables. Here, however, we measure the g factors of low-excitation states in 111 Cd and 113 Cd and show that they are sensitive to the nature of the collectivity in these nuclei in ways that the electric quadrupole observables are not. The particle-vibration model, which assumes spherical core excitations, cannot explain the g factors, whereas a particle-rotor model with a small, nonzero core deformation does. The contrast of the two models is made stark by the fact that they begin from the same limiting g-factor values: It is shown that when an odd nucleon occupies a spherical orbit with angular momentum j = 1/2, or a deformed orbit with j = 1/2 parentage, the particle-vibration model and the particle-rotor model both reduce to the same g-factor value in their respective limits of zero particle-vibration coupling or zero deformation.

A controlled and precise determination of the cross sections of the fusion reactions 7 Be(p, γ ) 8 B and 3 He( 4 He, γ ) 7 Be, which play an important role in determining the solar neutrino flux, necessitates the knowledge of a precise value of the electron-capture half-life of 7 Be. This half-life may depend on the material hosting the 7 Be atoms via small modifications of the electron density around the 7 Be nucleus. In this brief communication we report on the measurement of 7 Be implanted in four materials: copper, aluminum, sapphire, and PVC. The four results are consistent with a null host dependence within two standard deviations and their weighted average of 53.236(39) d agrees very well with the adopted value in the literature, 53.22 (6) d. The present results may exhibit a slight (0.22%) increase of the half-life at room temperature for metals compared to insulators that requires further studies.

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This paper demonstrates the feasibility of quadrupole moment measurements on isomeric levels populated in projectile fragmentation reactions. The neutron-rich 61 Fe(9/2 + ) [E * = 861 keV, T 1/2 = 239(5) ns] isomer was produced and spin aligned by the intermediate energy fragmentation of a 64 Ni beam and implanted in a Cd single crystal. Its spectroscopic quadrupole moment |Q s | = 41(6) e fm 2 agrees with mean-field based calculations using the finite-range Gogny force, suggesting a moderately deformed shape characterized by an intrinsic charge quadrupole moment Q 0 = −85 e fm 2 or Q 0 = +115 e fm 2 . The present measurement paves the way for future determinations of isomeric quadrupole moments in more exotic nuclei.