Gamma Rays from Proton Bombardment ofB10

The $\gamma$-ray spectrum resulting from the radiative decay of ${\mathrm{C}}^{11}$, produced by the proton bombardment of ${\mathrm{B}}^{10}$, has been investigated using thick and thin targets. Observations were made for proton energies ranging from 500 kev to 1.7 Mev. A broad resonance with a maximum at 780 kev appears well established. The compound nucleus decays in a one-step transition to the ground state of ${\mathrm{C}}^{11}$ with the emission of a $\gamma$ ray of energy approximately equal to 9 Mev. The existence of two other resonances, observed for proton energies of 0.95 and 1.33 Mev, is less certain.