Modelling of sawtooth induced redistribution of ICRF-heated minority ions

Experimental evidence indicates that sawtooth crashes tend to redistribute ICRF-heated particles. In particular, the redistribution may be inferred from the rapid reduction in the total fast ion energy following a sawtooth crash and the reheating rate of the central electron temperature. In the present work a qualitative model is given to describe the redistribution of ICRF-heated minority ions at sawtooth crashes in Tokamak plasmas. A crucial feature of the model is that it takes into account the finite width of the ICRF-heated particle orbits. Predictions of the model are compared, and found to be in agreement with, numerical simulations as well as experimental results from JET. (author) 3 refs., 3 figs., 1 tab