MONTE-CARLO APPROACH TO MODELING OF BOUNDARY-CONDITIONS FOR THE DIFFUSION EQUATION

A Monte Carlo scheme is proposed to obtain boundary conditions for the photon-diffusion equation. For a turbid medium with interfaces to non scattering media, we introduce an interpolated boundary, at a distance of a few transport-mean-free paths from the physical boundary, which acts as the secondary source emitting photons in various directions. T he ratio of the fluence rate to the flux is evaluated at both the inte rpolated and the physical boundaries. The derived boundary conditions are compared with other works and are supported by an independent simu lation of an effective source term.