A Model for Neutron Scattering Off Heavy Isotopes That Accounts for Thermal Agitation Effects

Abstract

The exact form of the differential scattering cross section for elastic scattering in an isotropic media with a Maxwellian velocity distribution is derived. Numerical examples show substantial neutron upscattering off heavy isotopes. Scattering resonances strongly affect neutron scattering, and it is found that for the lowest energy resonances of 238U, the average energy of the scattered neutron can be higher than the initial neutron energy.