The physics capabilities of an ignition-and-moderate-burn tokamak to explore the physics of burning plasmas and bum control on ash accumulation time scales are described. The machine provides physics capabilities comparable to those of the International Thermonuclear Experimental Reactor (ITER) for pulse lengths up to 120 s, but lacks the nuclear component testing, superconducting magnet technology, and long-pulse aspects of ITER's mission. Strong plasma shaping is adopted to reduce the 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 density limit), and safety-factor specified in the ITER physics guidelines. Acceptable peak heat fluxes to divertor target surfaces are maintained with an attached, high-recycling divertor operating scenario typical of present-day machines. A range of ignited and driven operating modes is available, including advanced modes prototypical of steady-state tokamak operation.