Stationary transport with partially reflecting boundary conditions. II

Abstract

We consider the stationary monoenergetic transport equation (the Lorentz model) in a semiinfinite geometry with most general nonmultiplying boundary conditions at the wall x=0, accounting for absorption, specular, diffuse, and ‘‘selective’’ reflection, or combinations thereof. Performing the numerical study of a (partially) ‘‘thermalizing’’ wall, we investigate the density profile n(x), the Milne extrapolation length xM, and the space dependent diffusion coefficient D(x) as functions of the accomodation and ‘‘selection’’ coefficients. The inversed density profile (equivalent to a negative diffusion coefficient) is numerically computed. As a simple analytically solvable example, a discrete velocity model is discussed in the Appendix.