Beta limits for the N=1 mode in rotating-toroidal-resistive plasmas surrounded by a resistive wall

摘要

The stability analysis of a high-beta toroidal tokamak plasma is carried out in the presence of toroidal flow, finite plasma resistivity, and a surrounding shell of finite electrical resistivity. The beta limits for the n=1 mode are set by the resistive-wall-tearing mode (RWTM), the ideal-wall-tearing mode (IWTM), and the ideal-plasma-resistive-wall mode (IPRWM). Slow plasma rotation suppresses the RWTM while the IPRWM is not directly affected by slow plasma flow. For small plasma resistivity, the IPRWM is stabilized by fast flow only. For large plasma resistivity, the IPRWM only exists in a plasma rotating faster than the typical tearing mode growth rate, and its instability threshold is a complicated function of the wall position and rotation frequency. Very fast rotation can destabilize the ideal kink through centrifugal effects. Furthermore, for b/a (wall radius/plasma radius) below a critical value, a stationary plasma is stable to the n=1 ideal kink and tearing mode for large values of beta. (C) 1998 American Institute of Physics. [S1070-664X(98)00210-9]. [References: 22]