Angular Distribution of 16.1-Mev Gamma Rays from the 163-kev Resonance in the ReactionB11(p, γ)C12

The relative thick-target yield, at a bombarding energy of 168 kev, of 16.1-Mev gamma rays from the reaction ${\mathrm{B}}^{11}(p, \gamma ){\mathrm{C}}^{12}$ has been measured at 0, 60, 90, and 120 degrees. The angular distribution is of the form $1-Acos\theta +B{cos}^2\theta$, with $A=0.19\mathrm{}\pm 0.06$ and $B-A=0.02\mathrm{}\pm 0.04$. The $cos\theta$ term is believed to be caused by interference between a resonance of spin and parity 1- at a bombarding energy of 1.4 Mev, and the resonance of spin and parity 2+ at a bombarding energy of 163 kev.