$\gamma -\gamma$ angular correlations were performed on the ${\mathrm{B}}^{12}$ 1.67 → 0.95 → 0 and 2.62 → 0.95 → 0 cascades following formation of the initial states via the ${\mathrm{B}}^{11}(d, p){\mathrm{B}}^{12}$ reaction. Deuteron energies of 1.70 and 3.13 MeV, respectively, were used. The results, when combined with previous information, lead to spin-parity assignments of $2^{+}$, $2^{-}$, and $1^{-}$ for the ${\mathrm{B}}^{12}$ 0.95-, 1.67-, and 2.62-MeV levels. Some information on the $\gamma$-ray decay modes of these states was obtained. This information is in good accord with previously reported work. ${\mathrm{B}}^{11}$+$d$ yield curves were obtained for the production of 0.95- and 1.67-MeV $\gamma$ rays and for the coincidence rate between these two $\gamma$ rays for deuteron energies between 0.55 and 3.05 MeV. Yield curves for production of the ${\mathrm{B}}^{12}$ 0.95-, 1.67-, and 2.62-MeV levels were constructed from these $\gamma$-ray yield curves.

• Received 13 October 1967

DOI:https://doi.org/10.1103/PhysRev.166.997