Excitation functions have been obtained for the ${\mathrm{F}}^{19}(p, \alpha \pi ){\mathrm{O}}^{16}$, ${\mathrm{F}}^{19}(p, {\alpha }_0){\mathrm{O}}^{16}$, ${\mathrm{F}}^{19}(p, \alpha \gamma ){\mathrm{O}}^{16}$, and ${\mathrm{F}}^{19}(p, p^{\prime }\gamma ){\mathrm{F}}^{19}$ reactions for proton energies of 1.2 to 5.4 Mev. The marked similarity of the pair and long-range alpha excitation functions is noted and in the proton energy interval 1.35 to 2.33 Mev the differences between the yields are explained by the penetration factors for alpha particles emitted from the excited states of ${\mathrm{Ne}}^{20}$. The average reaction cross section has been obtained for the ${\mathrm{F}}^{19}$+$p$ reactions by averaging the excitation functions over one-half Mev intervals. The result is compared to the cross section given by the continuum theory.

• Received 25 October 1957

DOI:https://doi.org/10.1103/PhysRev.109.1646