The 277-kev resonance for the production of ${\mathrm{O}}^{15}$ in its 7.61-Mev state was excited by proton bombardment of a thick TiN target. A three-crystal, scintillation spectrometer resolved gamma rays of 5.25±0.1 Mev, 6.10±0.1 Mev, and 6.65±0.15 Mev, with relative intensities of 25±6, 100, and 40±10, respectively. Direct ground state transitions have a relative intensity of less than 5. The total radiative capture yield in nitrogen is (2.7±0.6)×${10}^{-11\mathrm{}}$ reaction per proton. The intensity ratio of 6.10-Mev radiation to 5.25-Mev radiation, measured with a single-crystal spectrometer, is 7±3 percent lower at 90° to the beam than at 0°. The asymmetry eliminates pure $s$-wave capture. It is concluded that the capture state has spin $\frac{5}{2}$ and decays by dipole emission to the first three excited states of ${\mathrm{O}}^{15}$.

• Received 28 March 1955

DOI:https://doi.org/10.1103/PhysRev.99.107