On the interplay between turbulence and poloidal flows in plasmas

The radial profile of Reynolds stress has been measured in the plasma boundary region of tokamaks and stellarator plasmas. The electrostatic Reynolds stress (proportional to < E-tilder E-tildeθ>) shows a radial gradient close to the velocity shear layer location, showing that this mechanism can drive significant poloidal flows in the plasma boundary region of fusion plasmas. The generation of poloidal flows by Ion Bernstein Wave (IBW) is under investigation in toroidal plasmas. The radial gradient in the Reynolds stress increases with RF power and radial electric fields are modified at the RF resonance layer. (author)