Integrated Modelling of Sawtooth Oscillations in Tokamak Plasmas
The present understanding of sawtooth oscillations in tokamak plasmas is discussed. Predictive sawtooth modelling requires the integration of various aspects of tokamak physics, including transport, heating and current drive, MHD stability, kinetic effects and fast particle dynamics. In particular, fast particle distributions must be obtained self-consistently, taking into account auxiliary heating, fusion-produced alpha particles and the redistribution of fast ions due to sawtooth crashes and the relevant fast particle driven instabilities. The model proposed here is shown to be in fair quantitative agreement with experimental data and to provide a useful tool for the definition of a possible strategy for sawtooth control in fusion burning plasmas.