PLASMA-FLOW IN THE OUTER REGION OF THE RFX REVERSED-FIELD PINCH EXPERIMENT

Langmuir probes and collector samples have been exposed to the edge pl asma in the RFX reversed field pinch experiment to investigate the pla sma flow. Parallel and perpendicular drifts have been observed for pri mary ions and carbon impurities. Two models valid for a magnetized and an unmagnetized plasma have been applied and compared in order to der ive the parallel and perpendicular drift velocities. The perpendicular flow is accounted for by the radial electric field and shows a veloci ty shear, consistent with the change in sign of the radial electric fi eld in the edge region. The parallel flow increases going into the pla sma.