Freg Stephens

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We have developed a new method to study the order-to-chaos transition in rotational nuclei. Correlations between successive gamma rays are used to determine the average complexity of the intermediate levels and thereby the ratio of the interaction potential between levels to the level spacing. The measured ratios, 0.15 to 1.5, span the range from nearly(More)
We have deduced the cross section for 237 U(n, f) over an equivalent neutron energy range from 0 to 20 MeV using the surrogate ratio method. A 55 MeV 4 He beam from the 88 inch cyclotron at Lawrence Berkeley National Laboratory was used to induce fission in the following reactions: 238 U(α, α f) and 236 U(α, α f). The 238 U reaction was a surrogate for 237(More)
High-angular-momentum states in 108Cd were populated via the (64)Ni((48)Ca,4n) reaction at a beam energy of 207 MeV. Gamma rays were detected using the Gammasphere array. A rotational band has been observed with a dynamic moment of inertia and deduced lower limit of the quadrupole moment suggesting a major-to-minor axis ratio larger than 1.8:1, placing it(More)
Spectra of y rays associated with deep-inelastic products from the 1150-MeV ' 6Xe + ' 'Ta reaction have been measured. The yield of 10—20-MeV y rays initially increases rapidly with the excitation energy of the products and then more slowly for excitation energies in excess of 120 MeV. Statistical-model calculations with ground-state values of the giant(More)
Both the magnitude and alignment of the transferred angular momentum in the reaction Ho+ Ho have been measured as a function of Q value via continuum p-ray multiplicity and anisotropy techniques. Two regimes are observed: A low-Q-vaIue regime where the aligned angular momentum component dominates over the random components, and a large-Q-value regime where(More)