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.

/pdf/measured-g-factors-and-the-tidal-wave-description-of-1w2au1k9er.pdf

Measured g factors and the tidal-wave description of transitional nuclei near A = 100

Precessions of the 2
 1
 +
 states in198Pt and192Os have been measured in the enhanced transient hyperfine magnetic field acting on these nuclei as they recoiled through thin polarized cobalt foils. Two separate targets consisting of contiguous layers of198Pt and192Os electrodeposited on ∼1 μm and ∼4 μm Co foils were employed. The levels of interest were Coulomb excited by 80 MeV32S and 220 MeV58Ni beams and the precessions of the 2
 1
 +
 →0
 1
 +
 γ-ray angular distributions in both nuclides were measured simultaneously. The results of these studies are compared with recently reported similar studies in which ions of188Os and194Pt recoiled through thin polarized Fe foils. It is concluded that (i) the transient field acting on Pt in Fe is singularly anomalous, and (ii) the recent contention that the g-factors of the 2
 1
 +
 states in the event Pt isotopes may be substantially lower than had been reported in the literature cannot be sustained. This transient field discontinuity is examined in terms of possible molecular orbital electron vacancy sharing between Pt and Fe.

Disparity between the transient hyperfine fields for Pt and Os in Fe; an electron vacancy sharing interpretation

Magnetic moments have in general provided substantial information on the microscopic structure of nuclear states. Advances in technology have made it possible to measure, with reasonable accuracy, magnetic moments of nuclear states with lifetimes of the order of picoseconds or less. Improvements over the last decade involve all experimental aspects ranging from the availability of a wide variety of stable and radioactive beams, to the realization of highly segmented, high resolution detector arrays. A microscopic understanding of the hyperfine interaction between the nuclear moments and the ferromagnetic environment with which they interact has not yet been reached. Nevertheless, elegant applications of the new experimental techniques have allowed the measurement of nuclear moments of many nuclear states that were not accessible previously. Such measurements have shown how these moments vary with energy, spin and temperature in specific nuclei, or across isotopic chains. New results, in turn, have placed stringent constraints on theoretical calculations. The technical advances and selected highlights of relevant measurements across the periodic table are described in this review. Recent examples of applications of transient field and recoil-in-vacuum techniques in a radioactive beam environment are presented.

https://iopscience.iop.org/article/10.1088/0954-3899/34/9/R01/pdf

Magnetic moments of short-lived excited nuclear states: measurements and challenges

Salient features of transient magnetic fields are brought out from nuclear spin precession measurements on light ions penetrating polarized Fe-, Ni- and Gd-hosts. At low velocities ion fractions with singleK-shell vacancies, at high velocities H-like charge state fractions, can account for the observed precessions. The data suggest a sharp reduction of theK-shell field at a velocityvion≃0.5v0. Large degrees ofK-shell polarization have been derived for C- and O-ions. Measurements in different ferromagnets show that the transient fields scale with the polarized electron density of the host.

Light nuclei as distinct probes for transient magnetic fields

The g(2{sub 1}{sup +}) values in the even Te isotopes between {sup 122}Te and {sup 130}Te have been measured simultaneously, relative to each other, by the transient-field technique. In addition, g factors were also measured for the 3/2{sub 2}{sup +} and 5/2{sub 1}{sup +} levels in {sup 125}Te.

Relative g-factor measurements in the stable Te isotopes

The hyperfine dynamic field acting on fast ions traversing polarized iron foils has been measured as a function of the ion velocity in the region 0.03

Wolfhard Semmler

Papers

Velocity dependence of the dynamic magnetic field acting on swift O and Sm ions