Computational magnetohydrodynamics of time-dependent flows in toroidal systems

Two-dimensional calculations for initial-value problems in toroidal geometry are presented. The plasma is represented by a single fluid with finite electrical and thermal conductivities, but no viscosity and no particle-kinetic effects (no waves, turbulence, or trapping). The motion is studied in the poloidal plane, and there is no variation in the ignorable toroidal (phi) direction. A plasma initially at rest and at relatively low temperature is driven by two prescribed functions of time: the current in the toroidal windings I/sub c/ (t), and the total flux enclosed by the torus PSI (t). Currents and magnetic fields are then induced in the plasma, and the plasma moves. Naturally, all the currents, magnetic fields and velocities are three-dimensional vectors. This study gives the gross motion of the plasma in the poloidal plane, complete with pinching, bouncing, and toroidal column shift