The elastic scattering of alpha particles by ${\mathrm{C}}^{14}$ has been observed for alpha energies between 2.0 and 3.9 Mev and for ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=169\mathrm{}°, 149.5°, 140.8°, 125.3°, \mathrm{and} 90°$. The solid targets of 38.6% ${\mathrm{C}}^{14}$ were at least 8 kev thick. Energies of both the incident and scattered particles were measured with cylindrical electrostatic analyzers. The off-resonance cross sections were normalized to those derived from dispersion theory. Dispersion formalism applied to ${\mathrm{C}}^{14}(\alpha , \alpha ){\mathrm{C}}^{14}$ and ${\mathrm{C}}^{14}(\alpha , n){\mathrm{O}}^{17}$ data yields the resonance energies, angular momenta, parities, and reduced widths of several ${\mathrm{O}}^{18}$ levels. The levels of ${\mathrm{O}}^{18}$ considered had the following resonant energies, parities, and $J$ values: 8.051 Mev ($0^{+}$ or $1^{-1\mathrm{}}$), 8.222 Mev ($2^{+}$), 8.293 Mev ($3^{-}$), 8.966 Mev (≥$2^{+}$), and 9.0 to 9.2 Mev two levels, either ($2^{+}$$3^{-}$) or ($4^{+}$$3^{-}$).

• Received 23 January 1958

DOI:https://doi.org/10.1103/PhysRev.111.277