Differential cross sections for elastic scattering from the even-$A$ isotopes of Se have been measured at 6, 8, and 10 MeV. Inelastic scattering differential cross sections have been obtained at 6- and 8-MeV incident energies. The results have been analyzed in a coupled channel model to determine the isospin coefficients in the real and imaginary parts of the scattering potential and the deformation parameters ${\beta }_2$ appropriate to neutron scattering in these vibrational nuclei. Both the coupling to the first $2^{+}$ level and the imaginary scattering potential vary strongly between ${}_{}{}^{76}{}_{}{}^{}\mathrm{Se}$ and ${}_{}{}^{82}{}_{}{}^{}\mathrm{Se}$, and in such a way that their effects cancel each other for inelastic scattering. It is shown that with an adequate data set the strong coupling and isospin dependencies of neutron scattering can be separated. The normalization uncertainty of these measurements is about 7%, and the statistical precision ranges from 1 to 10%.

NUCLEAR REACTIONS ${}_{}{}^{76}{}_{}{}^{}\mathrm{Se}$, ${}_{}{}^{82}{}_{}{}^{}\mathrm{Se}(n,n)$ and ($n,n^{\prime }$), $E_n=6-8\mathrm{} \mathrm{and} 10$ MeV, ${}_{}{}^{78}{}_{}{}^{}\mathrm{Se}$, ${}_{}{}^{80}{}_{}{}^{}\mathrm{Se}\mathrm{}(n,n)\mathrm{}$, and ($n,n^{\prime }$), $E_n=8\mathrm{}$ MeV. Measured ($E_n,\theta$). Enriched targets. Coupled channel analysis.

• Received 1 December 1975

DOI:https://doi.org/10.1103/PhysRevC.14.933