The elastic-scattering angular distribution for the reaction of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ has been measured at $E_{\mathrm{lab}}=1503\mathrm{}$ MeV. Optical-model analysis shows that the data determine the nuclear potential between 4 and 6 fm, i.e., well inside the strong-absorption radius. Above ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=3\mathrm{}°$, the main contribution to the cross section comes from negative-angle scattering; however, the measured angular distribution is not sensitive to the position of the nuclear rainbow.

• Received 18 February 1985

DOI:https://doi.org/10.1103/PhysRevLett.54.1779