Continuum Modes of Arbitrary Rotating Tokamak Plasma

Full text: A theory for localized low-frequency ideal MHD modes in axisymmetric toroidal systems is discussed for tokamak plasma equilibria with both toroidal and poloidal equilibrium plasma flows. The general set of equations describing the coupling of shear Alfven and slow (sound) modes and defining the continuous spectrum of rotating plasmas in axisymmetric toroidal systems is derived in the form suitable for a standard stability analysis. The equations are applied to study the continuous spectra in large aspect ratio tokamaks. The unstable continuous modes in the case of predominantly poloidal plasma rotation with the angular velocity exceeding the sound frequency are found. Their stabilization by the shear Alfven coupling effect is studied. (author)