The impact of static magnetic perturbations on edge localized modes

The physics of edge localized modes (ELMs) mitigated by static magnetic perturbations (SMPs) with a toroidal mode number n=0 is studied. Three-field reduced magnetohydrodynamics (MHD) equations are solved by BOUT++ code. In the simulation, an effective mitigation of ELM has been observed when SMPs are added. A new mechanism of ELM mitigation is proposed that n=0 SMPs can excite a wide toroidal mode spectrum through E×B shearing rate which diminishes turbulent transport in the nonlinear phase. The mechanism is confirmed by the simulation results and relevant physical analysis in this paper.