Effect of sheared toroidal flow on the equilibrium of an axisymmetric plasma torus

Abstract

Several present day Tokamak experiments have reported large plasma rotations (of the order of sound speed) induced by neutral beam injection during auxiliary heating. The measured rotation profiles indicate that velocity shear can be significant. The authors examine the effect of such sheared flows on the equilibrium of Tokamak plasmas. Using the generalized MHD equilibrium equations for axisymmetric rotation and adopting a variational formulation, the authors carry out a detailed numerical investigation of the form of the magnetic surfaces and other equilibrium quantities as a function of the flow function profile. In certain limits they also obtain analytic expressions for the ellipticity and finite shift of the magnetic axis.