Classical Landauer coefficients for neutrons and photons in amorphous materials

Abstract

We use Boltzmann's transport equation to calculate the 3D version of the Landauer equation for incoherent neutrons and photons diffusing in a slab of amorphous material. We use the P-1 approximation to calculate the multiple-scattering transmission coefficient as a function of the diffusion coefficient. The 3D transmission coefficient is, apart from numerical coefficients, similar to the 1D case. The result is valid only for positions far away from the boundaries and for slabs having a thickness much greater than one mean free path.