Occurrence of Sawteeth in ITER and Their Effects on Alpha Particles and Stability
Authors: R.V. Budny, G.-Y. Fu, N.N. Gorelenkov, et al
Introduction Sawteeth alter the plasma, current, and fast ion profiles in present tokamak experiments. The central electron temperature, density, and neutron emission profiles are observed to flatten within the radius where the safety factor, qy = 1; so sawteeth reduce the central reactivity and fusion power. The plasma current also mixes to some degree since the safety factor in the center, qy(0), is observed to increase after sawtooth crashes [1]. Sawteeth may have beneficial effects as well. In TFTR, discharges with sawteeth do not have major high-b disruptions, suggesting that sawteeth and/or fishbones may inhibit these disruptions.