PROSPECTS OF A STATIONARY TOKAMAK REACTOR

Based on recent progress in world tokamak research, the prospects of continuous operation of a tokamak fusion power reactor are discussed. Efficient steady state operation (Q>30) becomes feasible when a large fraction of the plasma current (>70%) is driven by the bootstrap current. Moderate current (I(p) approximately 10-20MA) and an enhanced confinement mode of operation are the key for efficient steady state operation. High magnetic fields (B(t) = 8-11T) and high Troyon factors (beta(N)>3.5) are required to attain high beta(p) operation and a reasonably high fusion power density. Control of the current and edge pressure profiles is necessary for high beta(N) operation with a high bootstrap fraction. It is proposed that the Next Step Tokamak should be optimized for continuous operation as well as high current pulsed operation.