It is shown that ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ nuclei produced in the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$($\overrightarrow{n}$,$p$)${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ reaction are polarized. The polarization of ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ is measured through its beta-decay asymmetry. The analyzing "efficiency" $\epsilon =\frac{P_N}{P_n}$ (${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ polarization versus that of the incident neutron) for longitudinally polarized neutrons of average energy ${\overline{E}}_n=18\mathrm{}$ MeV is: $\left|\epsilon \right|=0.11\mathrm{}\pm 0.02$.

NUCLEAR REACTIONS ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$($\overrightarrow{n}$,$p$)${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$($\beta$) ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$; $E_n=18\mathrm{}$ MeV; measured $\beta$-decay asymmetry; deduced ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ polarization and analyzing efficiency.

• Received 30 November 1981

DOI:https://doi.org/10.1103/PhysRevC.25.2883