The impact of radial electric fields on turbulence spreading in the plasma boundary of fusion devices

We report measurements of turbulence drive and spreading in the edge region and Scrape-Off Layer (SOL) of the TJ-II stellarator in plasmas heated by ECRH and NBI. In addition, we show how these and various other relevant quantities can be modulated actively via edge biasing. The resulting control of SOL spreading via the edge ExB shear is important for the understanding and control of the SOL width in fusion-relevant devices.