No abstract

The differential cross sections for the elastic and the inelastic scattering of fast neutrons from W 182 , W 184 , and W 186 were experimentally determined at incident neutron energy intervals of <25 keV from 0.3 to 1.5 MeV. The excitation, by inelastic scattering, of states in W 182 was observed at 102±5 and 327dblO keV; in W 184 at 110±5, 360±10, 901±10, 1003±10 and 1120±10 keV; and in W 186 at 121±5, 398±10, 738±10, 863±10, 942±10 and 1035=L10 keV. The differential elastic-and inelastic-scattering cross sections were measured at 8 or more angles between 27 and 150 deg by means of a multiangle fast time-of-flight system. The resolution was sufficient to resolve most of the scattered neutron groups. The experimental results were interpreted in terms of a deformed optical model, coupled-channel direct interaction, and Hauser-Feshbach theory. Good agreement with measurement was obtained when the effects of resonance-width fluctuations and correlations were included.

Elastic and inelastic neutron scattering cross sections of natural germanium were measured in the incident neutron energy range 0.3-1.5 MeV with incident energy resolutions of ^20 keV. Neutron-velocity and 7-ray spectroscopic methods were employed to resolve the scattering to individual low-lying states. The results were interpreted in terms of the optical model and the statistical compound-nucleus model including effects due to fluctuations and correlations of resonance widths. Measured cross sections for inelastic scattering to a number of excited states in even Ge isotopes were reasonably well described by the statistical model of Hauser and Feshbach without corrections for width fluctuations and correlations.