Plasma response impact on RMP divertor footprint modeling for KSTAR

The striation pattern of heat loads on the divertor targets is determined by the plasma response to external resonant magnetic perturbations (RMPs) applied for suppression of edge localized modes (ELMs). Ideal and kinetic plasma response analysis with the general perturbed equilibrium code (GPEC) has shown that the extent of this striation pattern is very sensitive to the radial location of equilibrium truncation in GPEC, and that a significantly smaller extent is found if the equilibrium is truncated closer to the separatrix. Depending on the choice of truncation, it is shown in EMC3-EIRENE simulations that the peak heat load can be reduced by adjusting RMP coil parameters (phase, amplitude) within a window that is consistent with ELM suppression.