Numerical modelling of changes of edge plasma transport due to the presence of TEXTOR-DED

We use the 2D multifluid code TECXY to model possible changes of edge plasma transport in the vicinity of the dynamic ergodic divertor (DED) of TEXTOR tokamak. The increased effective radial transport coefficients in the stochastic magnetic field are calculated according to an analytical model of optimal paths. We also replaced our standard radial transport model (Alcator scaling) by a more sophisticated model accounting for drift turbulence. A parameter study is carried out in order to estimate possible changes of plasma profiles due to the different kinds of anomalous transport and the DED position. The influence on impurity radiation and screening is also investigated.