FINITE-ELEMENT MODELING OF THE PLASMA EDGE

Analysis of particle- and energy-transport in tokamak plasmas shows th e importance of the scrape-off layer (SOL) to achieve satisfying condi tions for a burning plasma in a fusion reactor. To take into account t he influence of complex geometrical features on transport, we develope d a 2D-fluid-code based on a Finite Element Method (FEM). Because this numerical scheme needs no regular grid structure, one can deal much m ore accurately with the plasma flow in non simply connected domains an d near limiter- or divertor-plates, where the magnetic field is inclin ed to the target. This permits a geometrically and physically more rea listic description of the interaction of plasma- and neutral-particles . Results from a coupled calculation between the FEM-code and a neutra l-gas Monte-Carlo-code (EIRENE) are discussed for the SOL of TEXTOR.