Electrostatic Turbulence and Transport in the Velocity Shear Layer of a Reversed Field Pinch Plasma

The electrostatic turbulence in the edge plasma of the RFX reversed field pinch experiment has been studied using Langmuir probes and a homodyne reflectometer. The radial particle flux driven by electrostatic fluctuations has been measured in the region where a double $\mathbf{E}\times \mathbf{B}$ velocity shear layer occurs. It is found that almost 100% of the particle flux at the edge is driven by electrostatic fluctuations. The naturally occurring $\mathbf{E}\times \mathbf{B}$ velocity shear has been shown to be close to that required by the Biglari-Diamond-Terry criterion for turbulence radial decorrelation.