Nuclear rainbow scattering with carbon isotopes

The phenomenon of nuclear rainbow scattering or far-side scattering observed in elastic scattering with projectiles of Z = 1 - 3 has provided valuable insights into interaction potentials and light ion reaction mechanisms. Until recently there had been no evidence that projectiles with Z > 3 could exhibit such nuclear-rainbow/farside scattering effects. However, within the past two years groups at CERN and at the Hahn-Meitner Institute have observed the clear signature of this phenomenon in 12C + 12C scattering at laboratory bombarding energies above about 20 MeV/nucleon. It is therefore of considerable interest to determine if heavier systems can also show nuclear rainbow scattering effects. Using the VICKSI accelerator system at the Hahn-Meitner Institute the authors have investigated this question for the systems 12C + 16O, 13C + 12C, and 13C + 14C with a 12C beam at 22 and 25 MeV/nucleon and 13C beam at 18 and 22 MeV/nucleon. Preliminary analysis indicates that the 13C + /sup 12-14/C systems show clear nuclear-rainbow/farside effects while the 12C + 16O system shows little evidence of this phenomenon