Operation of the IGNITEX tokamak

Summary Form only given, as follows. The operation of the IGNITEX ignition tokamak from breakdown to shutdown is discussed. The pulse length of the discharge is extended by precooling the magnet structure to liquid nitrogen temperature between pulses. RF cavity resonance is used to break down the neutral gas and initiate the plasma discharge in a controllable and reproducible way. The structure of the vacuum toroidal cavity modes has been investigated analytically. A numerical study of the field mode structure and the mode evolution during the plasma buildup has been carried out. Plasma current, equilibrium, shaping, and control are provided by an internal inductor with five pairs of single-turn coils which are independently powered by homopolar generators. Plasma coupling is maximized by the proximity of the poloidal field system to the plasma column. The conducting massive structure surrounding the plasma should damp plasma displacements. The MHD plasma equilibrium throughout a typical IGNITEX discharge has been analyzed. The IGNITEX experiment will operate basically in the L-mode without limiter. However, separatrix configurations of equilibrium are easily obtained by minor changes in the pulse shape of the elongation coils.<>