Simulation Study on the Influence of High Toroidal Mode Number n=4 RMP Phases on Plasma Response

Based on the equilibrium constructed from the EAST device discharge 115766, this study employed a linear plasma response model computed with the MARS-F program to investigate the influence of different RMP coil phase angles, under conditions of equal RMP coil current and zero phase difference. Simulation results indicate that the deformation of the plasma, under the influence of RMP fields, occurs only within a thin layer at the plasma boundary, manifesting a typical edge-peeling-like response. Notably, the plasma response at an RMP phase angle of 180° was more pronounced than at 0°, demonstrating that even with the same phase difference, different RMP phase angles can lead to significant variations in plasma response. This study provides crucial theoretical guidance for the design of RMP coil currents and their application in controlling Edge Localized Modes (ELMs) experiments.