The neutron total cross section of oxygen is measured in the energy regions from 0.6 to 0.9, 1.12 to 1.16, and 1.39 to 4.33 MeV. More than half of this region is surveyed with energy resolution and energy steps of about 2.5 keV. On the basis of these data and supplementary published data on the ($n,n$) angular distributions and the ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}(\alpha ,n)$ reaction, the ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ level energies in MeV and, in parenthesis, $J^{\pi }$ values and center-of-mass total widths, ${\Gamma }_T={\Gamma }_n+{\Gamma }_{\alpha }$ in keV, are: 5.696 (${\frac{7}{2}}^{-}$, 3.4); 5.731 (not ${\frac{1}{2}}^{+}$, <1.0); 5.867 (${\frac{3}{2}}^{+}$, 6.6); 5.937 (${\frac{1}{2}}^{-}$, 32); 6.354 (${\frac{1}{2}}^{+}$, 124); 6.860 (not ${\frac{1}{2}}^{+}$, <1.0); 6.970 (not ${\frac{1}{2}}^{+}$, <1.0); 7.163 (${\frac{5}{2}}^{-}$, 1.4); 7.20 (${\frac{3}{2}}^{+}$, 280); 7.377 (${\frac{5}{2}}^{+}$, 0.5); 7.380 (${\frac{7}{2}}^{-}$, 1.2); 7.56 (${\frac{3}{2}}^{-}$, 500); 7.685 (${\frac{7}{2}}^{-}$, 18); 7.955 (${\frac{1}{2}}^{+}$, 90); 7.99 (${\frac{1}{2}}^{-}$, 260); 8.058 (${\frac{3}{2}}^{+}$, 86); 8.18 (${\frac{1}{2}}^{-}$, 69); and 8.20 (${\frac{3}{2}}^{-}$, 52). Resonances are not observed for known ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ levels at 5.215 and 7.573 MeV; these levels have ${\Gamma }_T<0.1\mathrm{}$ keV. The previously reported narrow ${\frac{3}{2}}^{+}$ level at 7.694 MeV does not exist. Many of the results are based on a multilevel $R$-matrix analysis; this is also extended to the published ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}\mathrm{}(n,n)\mathrm{}$ and ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}(\alpha ,n)$ cross sections for energies corresponding to ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ excitations up to 9.5 MeV. This extension shows that there are two levels rather than only one near 8.47 MeV and that the 9.42-MeV level has $J^{\pi }={\frac{3}{2}}^{-}$. Other assignments are confirmed. The most accurate excitation energies below 9.5 MeV are reviewed from the literature and the ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$-${}_{}{}^{17}{}_{}{}^{}\mathrm{F}$ mirror structure is reviewed.

• Received 15 January 1973

DOI:https://doi.org/10.1103/PhysRevC.8.545