Shear flow generation due to electromagnetic instabilities

Abstract

Shear flow is the most important ingredient governing nonlinear behaviour of many types of plasma instability. Electromagnetic effects on shear flow generation have been studied for an electromagnetic drift wave called resistive drift-Alfvén mode (RDAM) and a global MHD mode called resistive wall mode (RWM). For RDAM it is found that the generated shear flow stabilizes the dominant modes; however, other modes are destabilized. For RWM Maxwell stress due to magnetic fluctuations has a tendency to suppress the poloidal flow near the plasma surface, which gives almost the same saturation level for different initial poloidal flows, since the shear flow stabilization disappears.