Angular Dependence of the Neutron-Induced Fission Process. II

Abstract

The angular anisotropy of neutron-induced fission has been studied with a double fission chamber. For ${\mathrm{U}}^{235}$ at 7.4 Mev and ${\mathrm{Np}}^{237}$ at 14.3 Mev, the variation of the differential fission cross section was found to depend strongly on the fourth power of the cosine of the angle between the fission fragment and the neutron beam. For ${\mathrm{U}}^{235}$ a resonance-type dependence of the anisotropy on neutron energy has been observed. Qualitative indication that the light and heavy fission fragment groups have slightly different anisotropies has been obtained in the case of ${\mathrm{Np}}^{237}$ at 14.3 Mev.