| Popis: |
The differential cross sections for the elastic and the inelastic scattering of fast neutrons from ${\mathrm{W}}^{182}$, ${\mathrm{W}}^{184}$, and ${\mathrm{W}}^{186}$ were experimentally determined at incident neutron energy intervals of $\stackrel{\mathrm{\ensuremath{\sim}}}{l}$ 25 keV from 0.3 to 1.5 MeV. The excitation, by inelastic scattering, of states in ${\mathrm{W}}^{182}$ was observed at 102\ifmmode\pm\else\textpm\fi{}5 and 327\ifmmode\pm\else\textpm\fi{}10 keV; in ${\mathrm{W}}^{184}$ at 110\ifmmode\pm\else\textpm\fi{}5, 360\ifmmode\pm\else\textpm\fi{}10, 901\ifmmode\pm\else\textpm\fi{}10, 1003\ifmmode\pm\else\textpm\fi{}10 and 1120\ifmmode\pm\else\textpm\fi{}10 keV; and in ${\mathrm{W}}^{186}$ at 121\ifmmode\pm\else\textpm\fi{}5, 398\ifmmode\pm\else\textpm\fi{}10, 738\ifmmode\pm\else\textpm\fi{}10, 863\ifmmode\pm\else\textpm\fi{}10, 942\ifmmode\pm\else\textpm\fi{}10 and 1035\ifmmode\pm\else\textpm\fi{}10 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. |
