PHYSICS CAPABILITIES OF AN IGNITION AND MODERATE-BURN EXPERIMENT BASED ON ITER PHYSICS GUIDELINES

The physics capabilities of an ignition-and-moderate-bum tokamak to ex plore the physics of burning plasmas and burn control on ash accumulat ion time scales are described. The machine provides physics capabiliti es comparable to those of the International Thermonuclear Experimental Reactor (ITER) for pulse lengths up to 120 s, but lacks the nuclear c omponent testing, superconducting magnet technology, and long-pulse as pects of ITER's mission. Strong plasma shaping is adopted to reduce th e cost relative to ITER. Using ITER guidelines to evaluate the physics performance, this machine has the same ignition margin as ITER's, and operates within the limits on beta, density (i.e., the Greenwald dens ity limit), and safety-factor specified in the ITER physics guidelines . Acceptable peak beat fluxes to divertor target surfaces are maintain ed with an attached, high-recycling divertor operating scenario typica l of present-day machines. A range of ignited and driven operating mod es is available, including advanced modes prototypical of steady-state tokamak operation.