The influence of resonant magnetic perturbations on edge transport in limiter H-mode plasmas in TEXTOR

In this contribution, we report on experimental results on edge transport in limiter H-mode plasmas in TEXTOR under the influence of the Dynamic Ergodic Divertor (DED). These plasmas are characterized by a pedestal structure mainly visible in the electron density, resulting in increased electron pressure gradients of up to 30 kPa/m over a pedestal width of 25 mm at high pedestal collisionalities (nu(e.) = 1 - 10), and with high frequency ELMs in the range of 300-1500 Hz. Under the influence of DED the pedestal pressure is gradually reduced and completely collapses to L-mode when the laminar zone extends all the way across the pedestal width. Toroidal plasma rotation is maintained at H-mode levels by the torque introduced by DED in the stochastic region. The perturbed magnetic topology has been optimized to access conditions with a density pump-out which are strongly governed by wall pumping capabilities in TEXTOR. (C) 2009 Elsevier B.V. All rights reserved.