Angular distributions have been measured for transitions to ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ states up to 7.43 MeV in excitation populated in the ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$(${}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^6{}_{}{}^{}\mathrm{He}$)${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ reaction at $E_{{}_{}{}^7{}_{}{}^{}\mathrm{Li}}=34\mathrm{}$ MeV. Elastic scattering of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ and ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ at 34 MeV from ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$ was also performed and optical model parameters were determined from fits to the measured angular distributions. These optical model parameters were used in finite-range distorted-width Born-approximation analyses of the single nucleon transfer data to extract spectroscopic factors for states at 0.0, 1.634, 4.247, 5.785, 6.722, and 7.424 MeV excitation in ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$. Spectroscopic factors obtained from this reaction agree well with those from light-ion transfer reactions. However, the $2s_{\frac{1}{2}}$ calculation for the ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ ground state is out of phase with the data by 7°. The "$j$-forbidden" $4^{+}$ state at 4.247 MeV excitation is found to be weakly excited in the ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$(${}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^6{}_{}{}^{}\mathrm{He}$)${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ reaction.

NUCLEAR REACTIONS ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$(${}_{}{}^6{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$), (${}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$), (${}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^6{}_{}{}^{}\mathrm{He}$), $E=34\mathrm{} \mathrm{and} 37$ MeV; measured $\sigma \left(\theta \right)$; deduced optical model parameters, deduced $S$ for ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$. Natural targets, finite range DWBA analysis, resolution 150 keV, $\theta =1-50\mathrm{}°$, $\Delta \theta =2-2.5\mathrm{}°$.

• Received 4 August 1975

DOI:https://doi.org/10.1103/PhysRevC.12.1899