MHD Simulation of Resonant Magnetic Perturbations

Resonant magnetic perturbations (RMP) have been found effective in suppressing ELMs in the DIII-D experiment [1, 2] Simulations with the M3D code indicate that plasma rotation has an essential effect on the RMP. When rotation is below a threshold, the RMP magnetic field is amplified above the vacuum field, and acquires a helical structure. The magnetic field is stochastic in the outer part of the plasma, causing temperature and density loss. At higher rotation speed, the stochastic layer is thinner. The temperature is similar to the initial non rotating unperturbed state. Rotation and the screened RMP cause a density loss which extends into the plasma core.