$\alpha$-particle yields from the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}(n,\alpha ){}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^7{}_{}{}^{}\mathrm{Li}_{}^{*}{}_{}{}^{}$ reactions have been measured at eight angles between 0° and 150° for neutron energies between 200 and 1250 keV. A thick natural lithium target bombarded by a polsed proton beam provided a neutron-energy continuum. $\alpha$ particles from the two reactions were distinguished by measuring the sum of $\alpha$-particle and neutron flight times as well as $\alpha$-particle energies. Yield data were converted to c.m. differential cross sections and each angular distribution was fitted with a series of Legendre polynomials. Coefficients of the $P_0$ terms are compared with other measurements. The coefficients of the higher order terms are qualitatively interpreted in terms of the level structure of ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$.

NUCLEAR REACTIONS ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}(n,{\alpha }_0)$, ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}(n,{\alpha }_1)$; $E=0.2\mathrm{}-1.25$ MeV, measured $\sigma \left(\theta \right)$.

• Received 8 December 1975

DOI:https://doi.org/10.1103/PhysRevC.13.2149