No abstract

No abstract

No abstract

Angular distributions of fragment activities from neutron-induced fission of U 233 and Pu 239 have been measured and show in detail the energy dependence of these distributions. The theoretically expected difference in low-energy anisotropy for these nuclides, which have similar fission thresholds but significantly different target spins, was not observed. A statistical model of fission anisotropy is applied to the data from the low-spin target Pu 239 to determine the energy dependence of KQ, the standard deviation of the distribution in the angular-momentum projection on the nuclear symmetry axis. The anisotropics indicate an increase of KQ with energy in excess of the fission barrier, with K$ values for even-even fissioning nuclei at excitation energies approximately 1 Mev higher than those for odd-^4 nuclei. The effective moment of inertia about the symmetry axis, similarly obtained from application of a statistical model to the data, is found to be ^0.

No abstract