Fluorine-plus-Proton Reactions

The properties of certain energy levels in ${\mathrm{O}}^{16}$, ${\mathrm{F}}^{19}$, and ${\mathrm{Ne}}^{20}$ have been studied by observations on the alpha particles and inelastic protons from the bombardment of fluorine by protons. A highresolution magnetic analysis of the alpha-particle groups to the $2^{+}$ and $1^{-}$ levels in ${\mathrm{O}}^{16}$ from the ${\mathrm{F}}^{19}(p, \alpha ){\mathrm{O}}^{16*}$ reaction failed to reveal any doublet structure in these known levels. The angular distributions of the alpha-particle groups to these levels did not indicate degeneracy with a $2^{-}$ level, nor did a search for new excited levels in ${\mathrm{O}}^{16}$ up to 8.7-Mev excitation reveal a $2^{-}$ level. These results are not in agreement with the alpha-particle model of the ${\mathrm{O}}^{16}$ nucleus which predicts a $2^{-}$ state close in energy to the $2^{+}$ state.