Some Results of Transfer Matrix Calculations for Thermal Neutrons

Abstract

The transfer matrix method is used to solve the Milne problem for a half-space for neutrons interacting with a moderator at temperature T. Two different scattering models are considered. They are the free monatomic gas of arbitrary molecular mass with constant cross sections in the center-of-mass system, and the Nelkin kernel for water. Both models permit an additional 1/v absorption cross section. The authors have obtained accurate numerical values for the diffusion length, the extrapolated end point, the critical absorption strength, and the boundary heating for a variety of values of the parameters. Comparison is made both with other calculations and with experiments.