Numerical study on influences of parallel sonic wave damping, precession, and bounce resonances on resistive wall modes in CFETR

Adopting an 11 MA steady-state reversed magnetic shear equilibrium of the China Fusion Engineering Test Reactor, the influence of parallel sonic wave damping, precession, and bounce resonances on the resistive wall mode (RWM) at different plasma pressures and plasma toroidal rotations is numerically investigated using the MARS-K code. We find that the parallel sonic wave damping, precession, and bounce resonances have damping effects on the RWM. The RWM is stabilized by the parallel sonic wave damping at low plasma pressure. At the two q = 3 rational surfaces, the RWM is the most unstable, but the precession resonance mainly occurs at one of the q = 3 rational surfaces, so the RWM cannot be stabilized. In addition, the precession resonance and bounce resonance occur simultaneously, and there are two roots. One is the precession resonance root, and another is the bounce resonance root. The bounce resonance has a stabilizing effect on the RWM.