An effective-mass treatment of neutron slowing down

Abstract

A new concept of an effective mass in the slowing down of fast neutrons is introduced. This concept, by accounting for absorption in an increased effective mass, places scattering in the presence of absorption on a formally equivalent basis with pure scattering. Thus absorption in slowing-down theory need not be considered as a separate phenomenon, but only as a generalized form of pure scattering. For a mixture, the effective mass includes the effect of absorption in an effective single element. A model of the moderation process is considered which allows a description of the mixture by the simpler single-element equations.

Equivalence of Taylor Series Approximation with Transcendental Equation of Neutron Slowing Down Theory under Constant Cross Sections

“…( 8) of Ref. (1). We have thus demonstrated that as the order of approximation of the Taylor expansion series is increased indefinitely, we get the exact transcendental equation.…”