EX/8-4Ra Turbulent transport and plasma flow in the Reversed Field Pinch

Abstract. The results of an extensive investigation of electrostatic and magnetic turbulence in the edge region of two European Reversed Field Pinch (RFP) experiments EXTRAP-T2R and RFX are reported. In both experiments particle transport is driven by turbulence and almost 50 % of the particle losses is due to coherent structures emerging from the fluctuation background. It has been found that the collision of these structures results in a diffusion coefficient comparable to that due to the background turbulence. A spontaneous highly sheared E×B flow is observed in the edge region of both experiments. The flow shear is found to result mainly from the balance between the Reynolds Stress and the anomalous viscous losses. The results indicate that a turbulence self-regulation process is in action in the edge region