The polarization and the differential scattering cross section for neutrons scattered from ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$ have been measured for $0.075\le E_n\le 2.2$ MeV. These results, together with those from the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}(n,{\alpha }_0){}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}(n,{\alpha }_1){}_{}{}^7{}_{}{}^{}\mathrm{Li}_{}^{*}{}_{}{}^{}$ (0.48 MeV), ${}_{}{}^7{}_{}{}^{}\mathrm{Li}(\alpha ,\alpha ){}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^7{}_{}{}^{}\mathrm{Li}(\alpha ,{\alpha }^{\prime }){}_{}{}^7{}_{}{}^{}\mathrm{Li}_{}^{*}{}_{}{}^{}$ (0.48 MeV), and other reactions leading to states in ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$, have been simultaneously interpreted in one consistent $R$-matrix calculation. The calculated results are in good agreement with most of the data and give new information about states in ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$. The level parameters obtained for these states and the calculated reaction cross sections are consistent with the corresponding quantities in the mirror nucleus ${}_{}{}^{11}{}_{}{}^{}\mathrm{C}$. Quantitative explanations are given both for the well-known $\frac{1}{v}$ behavior of the cross section for the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}(n,\alpha ){}_{}{}^7{}_{}{}^{}\mathrm{Li}$ reaction and for the $\frac{{\alpha }_0}{{\alpha }_1}$ branching ratio.

• Received 26 March 1971

DOI:https://doi.org/10.1103/PhysRevC.4.380