Ellipticity criterion for flowing two-fluid high beta equilibria

摘要

An improved formalism for flowing two-fluid equilibria with nonuniform density is developed in the absence of dissipation. The system for axisymmetric equilibria can be expressed using second-order partial differential equations for the stream functions of the generalized vorticities of the electron and ion fluids. It is found that the equilibrium equations are elliptic when the poloidal ion flow speed is less than the sound speed. This property differs markedly from the single-fluid model. The two-fluid result is compared with that for the single-fluid model. It is important to determine if well-confined flowing plasmas satisfy this ellipiticity criterion throughout the plasma. Measurements of plasma poloidal flow velocities in high beta plasmas are therefore encouraged. (C) 2004 American Institute of Physics.