Redistribution of three-dimensional divertor footprint induced by time-varying resonant magnetic perturbations on EAST

摘要

Introduction One of the main concerns for future ITER H-mode operation is the control of heat and particle fluxes to the plasma facing components (PFCs)[1, 2]. The transient heat and particle fluxes to the divertor plates, mainly induced by the type-I edge localized modes (ELMs) can be controlled by applying resonant magnetic perturbations (RMPs). The RMP ELM suppression was first achieved on DIII-D and then reproduced on KSTAR, EAST and recently on ASDEX-Upgrade. Other devices have reported ELM mitigation effects with RMPs. But there still problems from localized stationary heat and particle loads under fixed RMP application. Because stable and unstable separatrix manifolds will form homoclinic tangles and intersect with the divertor target plates. Nonaxisymmetric helical striations are created on the divertor plates and the so-called strike point splittings introduce additional paths for heat and particles striking on the divertor plates. The localized stationary heat and particle load on the divertor target may exceed thermal stress limits and leads to excessive localized erosion, especially in the long pulse operation case. To avoid it, the distribution of heat and particle fluxes needs a dynamic control, which can be achieved by time-varying RMP fields.