Fast Neutron Penetration in Paraffin and Lithium Hydride

Time-of-flight measurements of the fast-neutron angular flux spectrum in CH₂ and LiH spheres have been made to test shielding calculations. The spheres were excited with an isotropic photofission neutron source. Measurements were compared with discrete ordinates and Monte Carlo calculations. The major calculational difficulty was found to be the representation of the zero-degree flux in the discrete ordinates program.