The differential cross section angular distribution for ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ elastic scattering from ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ was measured at 154 MeV lab energy for center-of-mass angles up to 66°. The data exhibit forward-angle diffractive structure and a large-angle falloff similar to that of refractive nuclear scattering. An optical-model analysis with Woods-Saxon form factors and standard fitting criterion yields a broad continuum of admissible real central potential depths $\mathrm{}\left|V\right|\mathrm{}\sim 120-200$ MeV rather than the multitude of discrete parameter families encountered at lower bombarding energies. The best fit to the data selects a $\mathrm{}\left|V\right|\mathrm{}$ near 160 MeV. A Woods-Saxon squared form factor as well as a microscopic folding-model potential have also been investigated in fitting the data.

NUCLEAR REACTIONS ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$(${}_{}{}^6{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$), $E_L=154\mathrm{}$ MeV: measured $\frac{d\sigma }{d\Omega }$; optical-model analysis.

• Received 31 December 1979

DOI:https://doi.org/10.1103/PhysRevC.21.1656