The reaction ${}_{}{}^{50}{}_{}{}^{}\mathrm{Cr}$(${}_{}{}^7{}_{}{}^{}\mathrm{Li}$,${}_{}{}^6{}_{}{}^{}\mathrm{He}$)${}_{}{}^{51}{}_{}{}^{}\mathrm{Mn}$ was investigated at extreme forward angles, $1.6°\le \theta \le 12°$, in order to study the $j$ dependence for the (${}_{}{}^7{}_{}{}^{}\mathrm{Li}$,${}_{}{}^6{}_{}{}^{}\mathrm{He}$) reaction at 28 MeV. The ${}_{}{}^6{}_{}{}^{}\mathrm{He}$ ejectiles were detected with a position-sensitive (helix) counter in the focal plane of an Enge-split-pole spectrograph. A total energy resolution of about 30 keV was obtained. The angular distributions for seven low-lying states in ${}_{}{}^{51}{}_{}{}^{}\mathrm{Mn}$ show a pronounced $j$ dependence for angles below 7° and the expected $l$ dependence at angles $\theta \ge 9°$. Finite-range distorted-wave Born approximation calculations which include recoil effects reproduce the $j$-dependent angular distributions very well and permit a clear distinction between $p_{\frac{3}{2}}$, $p_{\frac{1}{2}}$, $f_{\frac{7}{2}}$, and $f_{\frac{5}{2}}$ final state angular momenta. The relative spectroscopic factors deduced were in reasonable agreement with those obtained in a recent ${}_{}{}^{50}{}_{}{}^{}\mathrm{Cr}({}_{}{}^3{}_{}{}^{}\mathrm{He},d){}_{}{}^{51}{}_{}{}^{}\mathrm{Mn}$ reaction study.

NUCLEAR REACTIONS ${}_{}{}^{50}{}_{}{}^{}\mathrm{Cr}$(${}_{}{}^7{}_{}{}^{}\mathrm{Li}$,${}_{}{}^6{}_{}{}^{}\mathrm{He}$)${}_{}{}^{51}{}_{}{}^{}\mathrm{Mn}$, $E_{\mathrm{Li}}$ MeV; measured $E_{{}_{}{}^6{}_{}{}^{}\mathrm{He}}$ and $\sigma (\theta ,E_{{}_{}{}^6{}_{}{}^{}\mathrm{He}})$ in split pole spectrograph with 30 keV resolution. Finite-range-DWBA analysis, deduced $j_{\mathrm{transfer}}$, spectroscopic factors.

• Received 10 October 1980

DOI:https://doi.org/10.1103/PhysRevC.23.742