Average magnetic moments as well as information on the time evolution of the continuum structure of 152Dy at high spin have been obtained using the transient hyperfine magnetic field acting on fast ions traversing a thin, magnetized gadolinium foil. 152Dy nuclei were populated by the Ge-76(Se-80,4n)152Dy fusion-evaporation reaction at E(Se-80) = 326.5 MeV. The target-ferromagnet arrangement corresponds to a time window of about 70 < t < 1100 fs, during which the excited nuclei experience the transient field interaction. The statistical gamma-rays, as well as the high-energy, E-gamma > 1200 keV, gamma-rays contributing to the collective E2 ''bump,'' exhibit a negligible precession, in accordance with the very short lifetimes of these states. The precession of the angular distribution of discrete yrast gamma-rays deexciting the nucleus from spin I approximately 35HBAR down yields an average magnetic moment for states with 43HBAR greater-than-or-equal-to I greater-than-or-equal-to 31HBAR. The resulting = 0.21(2) is considerably lower than the collective value Z/A approximately 0.43 and indicates an appreciable contribution from aligned neutrons to the lower-spin region populated within the above time frame. The results are discussed in the framework of model calculations of the gamma-ray cascade.

We have measured \ensuremath{\gamma} rays in coincidence with $^{12}\mathrm{C}$ fragments from the fission of $^{56}\mathrm{Ni}$ produced with the $^{32}\mathrm{S}$${+}^{24}$Mg reaction at ${\mathit{E}}_{\mathrm{lab}}$=140 MeV. These data provide insight into the fission process in this light system by giving information about the energy and spin sharing between the $^{12}\mathrm{C}$ and $^{44}\mathrm{Ti}$ fragments, and the spin alignment of the lighter, $^{12}\mathrm{C}$ fragment. The spin transfer and the nuclear ``temperature'' at scission deduced from this measurement can be related to the compound-nucleus spin and potential energy at scission. The results indicate a statistical decay process consistent with the predictions of the transition-state model employing newer estimates of the spin- and mass-asymmetry-dependent saddle-point energies and corresponding shapes. No evidence is found for the spin alignment of the $^{12}\mathrm{C}$ fragments, contrary to what might be expected for a deep-inelastic scattering origin of the fully energy damped yields.

The /ital g/ factor of the 10 995 keV,/ital J//sup ..pi../=59/2/sup /minus//, and/ital T//sub 1/2/=0.8 ns level in /sup 147/Gd has beendetermined by the transient field method for ions recoiling through amagnetized Gd foil at a temperature of 100 K. The/sup 76/Ge(/sup 76/Ge,5/ital n/)/sup 147/Gd reactionat /ital E/(/sup 76/Ge)=310 MeV was used to provide high recoil velocity. A 100 ps flight time in vacuum between the target and the ferromagnet of 100 ps ensured that the ..gamma..-ray cascades fed the 59/2 level before the recoil ions traversed the Gd foil. The /ital g/ factor was extracted from standard double ratios with the known parametrization of the transient field, yielding /ital g/=0.38(7). This value is in agreement with the predicted wave function and experimental single-particle moments in this mass region. Results for levels in /sup 146,148/Gd were also obtained.

A rotational band of 19 (possibly 20) transitions extending to spin ∼ 1312h̵ has been observed in 151Dy with an average dynamic moment of inertia I(2) = 79 h̵2 MeV−1. This band is identified as a superdeformed band in 151Dy. The value of I(2) agrees with cranked Strutinsky calculations. Similarities as well as striking differences with the superdeformed bands of neighboring nuclei are observed.