The transmission/escape probability (TEP) method for neutralparticle transport has recently been introduced and implemented forthe calculation of 2-D neutral atom transport in the edge plasma anddivertor regions of tokamaks. The results of an evaluation of theaccuracy of the approximations made in the calculation of the basicTEP transport parameters are summarized. Comparisons of the TEP andMonte Carlo calculations for model problems using tokamak experimentalgeometries and for the analysis of measured neutral densities inDIII-D are presented. The TEP calculations are found to agree ratherwell with Monte Carlo results, for the most part, but the need for afew extensions of the basic TEP transport methodology and forinclusion of molecular effects and a better wall reflection model inthe existing code is suggested by the study.
Multi-group diffusion of energetic charged particles