TOKAMAK EQUILIBRIA AND STABILITY WITH ARBITRARY FLOWS

The topic of plasma flows and their influence on the equilibrium and s tability properties of tokamak discharges is briefly reviewed. The sta bility of high-n ballooning modes in the presence of sheared toroidal rotation is discussed to highlight recent advances in our understandin g of the spatial structure and temporal evolution of these modes. The eikonal solution, which is mathematically equivalent to the normal mod e solutions at the lowest order in 1/n, may not be physically relevant for a variety of reasons. An analytic formulation of the normal mode problem for high-n ballooning modes in the presence of sheared toroida l flow in the high-beta large-aspect-ratio limit is presented. in cont rast to earlier studies, the present formulation allows for large plas ma shifts as well as accounting for changes in the shape of flux surfa ces due to rotation effects.