Self-consistent ▽ P and E × B drifts in a two-dimensional one-fluid edge plasma model

Abstract

Self-consistent poloidal diamagnetic and E × B drifts (presently without non-ambipolar effects) have been included in a two-dimensional single-fluid tokamak edge plasma transport model. Drift flows are seen to dominate the poloidal flow near the seperatrix where large pressure and potential gradients exist. A poloidal current of 65 A/cm 2 is estimated to arise from the diamagnetic drift that leads to a radial drift of approximately 10 m/s. The poloidal drifts add substantial mass and energy flow across the symmetry plane that makes the use of such boundary conditions questionable. It is recommended that the computational domain include both divertors when drifts are dominant.