Anomalies in the Scattering of Alpha Particles by Carbon

Abstract

Angular distributions of elastic and inelastic scattering ( Q =-4.43 MeV) of alpha particles by the carbon nucleus have been measured at eight different alpha particle energies between 27.0 and 35.5 MeV. These data are discussed together with those reported previously in this journal and with those of other authors. Angular distributions for both elastic and inelastic alphas show remarkable variation with bombarding energy and cannot be explained with simple direct interaction theories. There appear anomalies in the angular distributions for E α in the neighbourhood of 30 MeV. Also in the excitation energy near 30 MeV in the compound system, some resonances were found in the elastic excitation function and in the integrated cross section for the inelastic scattering ( Q =-4.43 MeV). Even at such high excitation energies the effect of the compound system seems to be important.