Investigation of the turbulence intermittency in the scrape-off layer during the static DED operation in TEXTOR Y. Xu 1 , R. R. Weynants 1 , M. Van Schoor 1 , M. Vergote 1 , S. Jachmich 1 , B. Unterberg 2 , M. Mitri 2 , M. W. Jakubowski 2 , O. Schmitz 2 , K. H. Finken 2 , M. Lehnen 2 and the TEXTOR team Partners in the Trilateral Euregio Cluster (TEC): 1 Laboratory for Plasma Physics, Ecole Royale Militaire/Koninklijke Militaire School, Euratom-Belgian State Association, Avenue de la Renaissance 30, B-1000 Brussels, Belgium 2 Institute fur plasmaphysik, Forschungszentrum Juelich, D-52425Juelich, Germany 1. Introduction It has long been observed that the plasma transport in the scrape-off layer (SOL) is characterized by turbulent intermittency [1-4], which unfavorably increases wall erosion and reduces the divertor efficiency. In recent years, experiments in several machines [5-7] have shown the importance of an ergodized magnetic boundary in optimizing the plasma-wall interaction. In the static DED (dynamic ergodic divertor) operation on TEXTOR, a reversal of turbulent flux from radially outwards to inwards has been observed in the ergodic zone along with other changes of turbulence properties [8]. In this paper, we report the results about the impact of the static DED on the intermittent transport in the SOL of TEXTOR. 2. Experimental setup The experiments were performed in TEXTOR tokamak under the static m/n=6/2 DED configuration [7] with following ohmic discharge conditions: R/a=1.73/0.46 [m/m], B T =1.9 T, I p =200-360 kA, <n e >=(1.6-3.5)·10 19 m -3 . The dc DED current (I DED =6kA) was applied during the stationary phase of the discharge, which induced a perturbation field B r /B T ~10 -4 in the edge and thus stochastization of magnetic field lines in the plasma boundary [9, 10]. The measurements were mainly made by a fast reciprocating Langmuir probe array installed at the outer midplane. Two pins of the array were DC-biased to record the ion saturation current, I s , while the other two were poloidally separated to detect the poloidal electric field E s from their floating potential difference. The radial speed of the blobs is hence estimated by V r = Fig. 1 Discharge waveforms in a static 6/2 DED experiment on TEXTOR. (a) plasma current (I p ), line-averaged density and H a emission; (b) dc DED current; (c) radial position of fast probes (dotted line denotes limiter location); (d) ion saturation current. 34th EPS Conference on Plasma Phys. Warsaw, 2 - 6 July 2007 ECA Vol.31F, P-1.097 (2007)