Inelastic Scattering of 40.2-Mev Alpha Particles

Abstract

The differential cross section $\frac{{d}^{2}\ensuremath{\sigma}}{\mathrm{dEd}\ensuremath{\Omega}}$ has been measured at 25, 45, 90, 135, and 150 degrees in the laboratory system for the inelastic scattering of 40.2-Mev alpha particles from Al, V, Cu, Nb, Ag, Ta, and Th. Spectra obtained at 135 and 150 degrees have been analyzed in terms of the statistical theory of nuclear reactions. The differential cross section measured at smaller angles is incompatible with the statistical theory of nuclear reactions. A group of alpha particles with energy well below the Coulomb barrier is observed in the spectra of Ta and Th at large angles.