Sawtooth effects in elongated, high-current tokamak reactors

Transport simulations of elongated, high-current tokamaks, such as the International Tokamak Reactor and the Tokamak Ignition Burn Experimental Reactor ignition devices, predict that broad sawtooth oscillations will appear in the experiments. As was noted previously in studies of the Compact Ignition Tokamak, the primary effect of broad sawtooth oscillations is to reduce fusion power production on the average through profile flattening. Due to the separate times scales for energy and current diffusion between sawtooth crashes, the simulations also produce peaked pressure profiles over a large low shear region. Pressure-driven modes are predicted to be unstable in this case