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.

Automated summary

The striation pattern of heat loads on divertor targets depends on the plasma response to external resonant magnetic perturbations applied for ELM suppression. Analysis shows that the extent of this pattern is sensitive to the radial location of equilibrium truncation, and a smaller extent is found if the truncation is closer to the separatrix. Simulations demonstrate that by adjusting RMP coil parameters, the peak heat load can be reduced within the range of ELM suppression.