Isospin-Forbidden and - AllowedO16(d,α)N14Reactions

Cross sections are reported for the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}(d,\alpha ){}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ transitions to the ground and first excited state for $2 \mathrm{MeV}\le E_d\le 14 \mathrm{MeV}$ and 8-18 angles. An $S$-matrix analysis of the isospin-forbidden reaction to the ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$(2.31-MeV) $T=1\mathrm{}$ state yields level parameters, spins, and parities for a large number of ${}_{}{}^{18}{}_{}{}^{}\mathrm{F}$ intermediate states. Several of these are analogs of $T=1\mathrm{}$ levels in ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$. The mechanisms for the isospin-forbidden reaction is entirely compound nuclear and for the isospin-allowed transition is predominantly so. The isospin impurity, averaged over 1-MeV intervals, is 3-10% for $10\le E_x\left({}_{}{}^{18}{}_{}{}^{}\mathrm{F}\right)\le 20$ MeV. Analysis by peak counting indicates that $\frac{{\Gamma }_J}{D_J}\sim 1$ at $E_x=14\mathrm{}$ MeV and that the average coherence width increases from ∼ 100 keV at $E_x=14\mathrm{}$ MeV to ∼ 500 keV at $E_x=20\mathrm{}$ MeV.