Emission of alpha particles in the fission process

Abstract

The angular distribution with respect to the incident neutrons of the long-range alpha particles emitted in the fission of U²³⁸ by 14-MeV neutrons is investigated using the emulsion technique. The shape of this distribution suggests that the alpha emission is a compound nucleus evaporation process. The energy spectrum of alphas emitted in the fission of U²³⁵ is also reasonably accounted for by a new mechanism proposed here which assumes that the emission of alphas takes place from the neck of the distorted compound nucleus with a charge polarization along the fragment axis.