Simulation of dense recombining divertor plasmas with a Navier–Stokes neutral transport model

Abstract

A two-dimensional combined edge plasma Navier–Stokes neutral transport model is presented for the simulation of dense recombining divertor plasmas. This model includes ions, electrons, and neutral atoms which undergo Coulomb collisions, electron impact ionization, ion–neutral elastic collisions, three-body and radiative recombination, and neutral–neutral collisions. The advanced fully implicit solution algorithm is briefly described and a variety of results on a model geometry are presented. It is shown that interesting neutral flow patterns can exist and that these flows can convect significant energy. A solution that ignores neutral–neutral collisions is shown to be quantitatively different from one that includes neutral–neutral collisions. Solutions are also shown to be sensitive to the plasma opacity for Lyman α radiation.