STOCHASTIC INTERACTION BETWEEN TAE AND ALPHA-PARTICLES

Toroidicity-induced Alfven eigenmodes (TAE) interact with thermonuclea r alpha particles in the intrinsic stochasticity regime. In this contr ibution, the investigation of this interaction based on the numerical integration of the equation of motion of alpha particles in the tokama k is presented. From the first results for ITER parameters follows tha t the strongest stochasticity appears in the region of trapped/passing boundary. Here, alpha particles jump stochastically between these two regimes with quite impressive radial excursion (approximate to 0.5 m amplitudes). We have found a similar chaotic behaviour also for much l ower energies (about 350 keV).