Stationary effect of energetic trapped particles on the resonant excitation of the ideal ballooning mode

The effect of the contribution of zero frequency (stationary) energetic trapped particles on magnetohydrodynamic modes and the resonant excitation of these particles is studied on the basis of the dispersion relation which is applicable to both the internal kink mode and the ballooning mode in tokamaks. The stability window is found to be significantly enlarged by the steady contribution of energetic trapped particles.