The passage of fast neutrons through lead and iron

Abstract

Results are given of measurements of the spatial distribution in lead and iron of fast neutrons from sources of energies E₀ = 4 and 14·9 MeV and of reactor neutrons.

A method of solving the Boltzmann equation in media which slow down neutrons by inelastic collisions with nuclei has been developed† in order to calculate the space and energy distribution of fast neutrons at large distances from the source. The anisotropy of elastic scattering is taken into account, but the loss of neutron energy in elastic scattering is neglected.