Abstract. The issues of linear stability of low frequency perturbative and nonperturbative modes in advanced tokamak regimes are addressed based on recent developments in theory, computational methods, and progress in experiments. Perturbative codes NOVA and ORBIT are used to calculate the effects of TAEs on fast particle population in spherical tokamak NSTX. Nonperturbative analysis of chirping frequency modes in experiments on TFTR and JT-60U is presented using the kinetic code HINST, which identified such modes as a separate branch of Alfvén modes - resonance TAE (R-TAE). Internal kink mode stability in the presence of fast particles is studied using the NOVA code and hybrid kinetic-MHD nonlinear code M3D.
IAEA 2001