A radioactive nuclear beam of 10.2 MeV ${}_{}{}^6{}_{}{}^{}\mathrm{He}$, with typical intensity 5×${10}^4$ ${\mathrm{s}}^{\mathrm{-}1}$, was produced via the ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$${(}^7$Li${,}^6$He${)}^{10}$B reaction and elastically scattered from targets of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{\mathrm{nat}}{}_{}{}^{}\mathrm{Ni}$, and ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$. Scattering from C and Ni was observed through sufficiently large angles (up to 60° c.m. and 85° c.m., respectively) to show large deviations from Rutherford scattering. The Au target gave, as expected, pure Rutherford scattering. Optical potential previously used for low-energy ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ and ${}_{}{}^8{}_{}{}^{}\mathrm{Li}$ ions generally accounted for the shapes of the angular distributions but, for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, predict oscillations not present in the ${}_{}{}^6{}_{}{}^{}\mathrm{He}$ data. ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ optical potentials predict much smaller deviations from Rutherford scattering than those observed.

• Received 17 June 1994

DOI:https://doi.org/10.1103/PhysRevC.51.178