Rotation and ion temperature measurements in tokamaks and stellarators

Radial structures of plasma rotation and ion temperature are experimentally studied in JIPP T-IIU and JFT-2M tokamak, CHS and Heliotron-E heliotron/torsatron and Wendelstein 7AS stellartor devices. The profiles of the radial electric field are derived from the rotation profiles. The mechanism determining the rotation is studied and the relation between plasma rotation (radial electric field) shear and transport barrier is discussed. Plasma rotation profiles are determined from the balance of momentum deposition and the perpendicular and parallel viscosities. The parallel viscosity, which predominantly damps the toroidal velocity in heliotron/torsatron and stellarator devices, is found to be neoclassical. On the other hand, the perpendicular viscosity, which is dominant in dictating the toroidal rotation in tokamaks, is anomalous. The transport analysis based on density and electron and ion temperature profiles shows that the sheared plasma rotation (radial electric field) improves particle and electron and ion heat transport both in bulk and edge plasma regions of tokamaks. copyright 1995 American Institute of Physics