Elastic Scattering ofC12from Gold

Abstract

The angular distribution of ${\mathrm{C}}^{12}$ ions elastically scattered by gold has been measured at the following laboratory energies: 118\ifmmode\pm\else\textpm\fi{}2, 101\ifmmode\pm\else\textpm\fi{}2, 79.4\ifmmode\pm\else\textpm\fi{}3, and 73.6\ifmmode\pm\else\textpm\fi{}3 Mev. Heavy ions from the Berkeley heavy-ion linear accelerator (HILAC) were recorded in two Ilford E-1 plates from a scattering angle of 19\ifmmode^\circ\else\textdegree\fi{} to 159\ifmmode^\circ\else\textdegree\fi{}. In all cases the differential cross sections exhibited a Coulomb-like behavior at small angles, a rise above Coulomb of about twenty percent as the scattering angle increased, and then a rapid drop below Coulomb in much the same manner as alpha particles scattered from heavy elements in the 20-40 Mev range. The Blair "sharp cutoff" model reproduces closely the character of the data; however, small oscillations predicted from the model are not experimentally observed. Interaction distances of (11.8\ifmmode\pm\else\textpm\fi{}0.3, 12.1\ifmmode\pm\else\textpm\fi{}0.3, 11.85\ifmmode\pm\else\textpm\fi{}0.4, and 11.85\ifmmode\pm\else\textpm\fi{}0.45)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}13}$ cm, respectively, for the foregoing energies are inferred from application of the Blair model.