The gamma radiation produced in the ${\mathrm{Be}}^9(p, \gamma ){\mathrm{B}}^{10}$ reaction at proton energies of approximately 300 kev was investigated with scintillation spectrometers. A three-crystal scintillation spectrometer detected 6.7±0.15, 6.0±0.1, 5.1±0.1, and 4.7±0.15-Mev gamma rays with relative intensities (±25 percent) of 0.15, 0.40, 1.00 and 0.45, respectively. A thick target yield of (1.2±0.3)×${10}^{-10\mathrm{}}$ gamma per proton at 315-kev proton energy was measured for gamma radiation of 5.1-Mev energy. These gamma rays are produced in transitions to the ground-state and low-lying levels in ${\mathrm{B}}^{10}$ and their relative intensities and yield imply spin $1^{-}$ for the level at 6.89 Mev. A limited single-crystal spectrometer detected 0.41±0.02, 0.72±0.02, 1.03±0.03, and 1.43±0.03-Mev gamma rays corresponding to transitions between the low-lying levels in ${\mathrm{B}}^{10}$. The angular correlation of the 0.72- and 1.03-Mev gamma rays was found to be consistent with a spin of $1^{+}$ or $2^{+}$ for the first excited state of ${\mathrm{B}}^{10}$.

• Received 7 February 1955

DOI:https://doi.org/10.1103/PhysRev.98.1310