ITER plasma modelling and MHD stability limits

Contributions of 1.5-D transport modelling to assess ITER performance, operation and MHD stability limits are reviewed. Energy and particle transport models include a prescription for sawtooth oscillation, edge recycling and the edge transport barrier for the H mode. Comparisons with experiments show that these modelling assumptions can explain many experimental features. However, recent ρ* experiments suggested that ions and electrons would scale differently with this parameter. Consequently, a modified ion transport expression is proposed and shown to allow better simulation of experiments. These models are then to predict ITER L and H mode reference profiles and the dynamic behaviour of an ignited plasma. The PRETOR transport profiles have been analyzed for MHD stability. It is found that the limits are gT = 3.4 for ballooning and gT = 4.5 for global modes for both L mode and H mode cases. Internal kinks and resistive modes have also been studied in less detail. A brief discussion is given of physical issues which remain to be resolved. (author). 9 refs, 5 figs