Radiation Pressure on Plasma Turbulence by Radio Frequency Waves

The use of radio frequency (RF) waves in fusion devices – primarily, to modify and control the heating and current profiles, and to subdue deleterious instabilities – has been gaining traction over the last few decades. The antennas or waveg- uide structures used for launching electromagnetic waves are usually located in the vicinity of the outer wall of a device. Consequently, for coupling RF power to core plasma, the waves have to propagate through a turbulent scrape-off layer plasma in the edge region. The RF waves can scatter off the turbulence, thereby altering the power profile coupled to the core. Simultaneously, the radiation pressure of the RF waves can affect the turbulence. Theoretically, it is convenient to analyze the two effects separately and explore the underlying physics. There have been a number of analytical and computational studies on the scattering of RF waves by different forms of plasma turbulence. This paper explores the impact of radiation pressure on turbulence.