EFFECTS OF TRAPPED THERMAL PARTICLES ON THE N=1 INTERNAL KINK MODE INTOKAMAKS

The effects of thermal trapped particles on the internal kink mode are studied using drift kinetic theory. For equal electron and ion temper atures, the trapped particles increase the marginal poloidal beta at q =1 substantially. For unequal temperatures, drift resonance with the h otter species is destabilizing and can lead to instability below the i deal magnetohyrodynamics threshold. An electrostatic potential is weak ly stabilizing for the internal kink. At high beta, fluctuations of tr apped particle modes couple to the internal kink mode and can lead to large displacements of the central region.