Numerical analysis of the influence of different kinds of transport on the edge plasma profiles in TEXTOR tokamak

The 2D multifluid code TECXY is a useful tool for investigating specific physical questions in the plasma edge of limiter tokamaks. The physical model is based on Braginskij-like equations. An analytical description of neutrals allows to take into account plasma recycling as well as sputtering processes. The code incorporates drift motions and currents in a fully self-consistent way, and the radial electric field in the transition layer inside the separatrix is derived from global ambipolarity. Our standard radial transport model (with prescribed anomalous radial transport coefficients) has been replaced by a more sophisticated model accounting for different kinds of turbulent transport. In particular, we assume that on closed magnetic surfaces the transport is driven by drift resistive ballooning instability (DRB) and by drift Alfven instability (DA). In the present paper we apply the extended TECXY code to analyze the changes of edge plasma transport due to the presence of DRB and DA. We use simplified analytical formulae from mixing length approximation and compare the results with those from the hitherto applied Alcator-like scaling. (author)