An Approximate Method for Treating Neutron Slowing Down

The slowing down density, q, of neutrons in a reactor may be decomposed into a sum of parts due to various nuclear species having corresponding scattering cross sections µ_s1, µ_s2, ···. An approximate relation between q_i and isotropic flux φ(u) (where u is the lethargy) is proposed. . The values of γ_i and ξ_i are derived and interpreted.