Bremsstrahlung-weighted integrated cross sections for photoproton and photoneutron emission from ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ to excited residual states in ${}_{}{}^{16}{}_{}{}^{}\mathrm{N}$ and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ have been measured by detecting the deexcitation γ rays emitted from these states in the residual nuclei. The results are compared with the previously reported ${}_{}{}^{17}{}_{}{}^{}(\gamma$,p) and ${}_{}{}^{17}{}_{}{}^{}(\gamma$,n) cross sections. About 90% of photoproton emission from ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ populates the ground-state ${(2\mathrm{}}^{\mathrm{-}}$) and the 0.298-MeV ${(3\mathrm{}}^{\mathrm{-}}$) level in ${}_{}{}^{16}{}_{}{}^{}\mathrm{N}$. It is concluded that this is the result of a single-particle excitation and emission process. The remaining photoproton emission, leading to the 0.120-MeV ${(0\mathrm{}}^{\mathrm{-}}$) and 0.397-MeV ${(1\mathrm{}}^{\mathrm{-}}$) levels, occurs during the preequilibrium stage or from the compound nucleus. The results further indicate that these decay fractions are approximately independent of excitation energy in ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$. For the ${}_{}{}^{17}{}_{}{}^{}(\gamma$,n${)}^{16}$O reaction, the results show that emission to bound states in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ is predominantly to the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ ground state ${(0\mathrm{}}^{+}$), with 4% of the decay from the ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ giant dipole resonance going to the 6.13-MeV ${(3\mathrm{}}^{\mathrm{-}}$) excited state; population of other bound states is not observed.

• Received 27 January 1989

DOI:https://doi.org/10.1103/PhysRevC.40.59