The yield and angular distributions of $\alpha$ particles from the ${\mathrm{O}}^{16}({\mathrm{Li}}^6, {\alpha }_0){\mathrm{F}}^{18}$ reaction were measured for the bombarding range 4.8 to 13.8 MeV. Nine distinct peaks were observed in the yield curve measured at 0° and had peak-to-valley ratios varying from 1.3 to 6.0. A fluctuation analysis of the yield curve gives a corrected coherence width $\Gamma =0.49\mathrm{}\pm 0.40$ MeV (c.m. system) in the excitation energy range of ${\mathrm{Na}}^{22}$ of 18.0 to 24.6 MeV for the sample size $n=5.3\mathrm{}$. This analysis predicts a direct reaction contribution to the differential cross section of 0 to 60%. Angular distributions were measured at seven energies: 5.50, 5.70, 6.22, 11.60, 12.20, 12.80, and 13.30 MeV, which correspond to peak and valley energies observed in the yield curve. At the three lowest bombarding energies, the angular distributions have little structure, while at the four higher energies they oscillate rapidly.

• Received 31 January 1968

DOI:https://doi.org/10.1103/PhysRev.176.1204