Validation of plasma response and turbulence simulation across KSTAR core magnetic islands

One of the biggest challenges for long-pulse ELM suppression is the control of the heat and particle fluxes' interaction with plasma-facing surfaces while simultaneously minimizing the impurities influx into the core plasma. Achieving these goals relies on our understanding of the transport in the presence of the 3D perturbation fields changing the magnetic topology of the plasma in the edge and core regions. In this work, we present the results from the recent KSTAR L-mode experiments showing increased turbulence near the X-point of the 2/1 core magnetic island resulting from the locked mode. We performed linear MHD simulations of the 2/1 LM island and validated the plasma response models in M3D-C1 and NIMROD against the available KSTAR ECE-I measurements. The results of these MHD simulations were used to initiate the GTC simulations to validate the transport models. Both, the experimental and linear plasma response modeling results with M3D-C1 and NIMROD codes have shown that the physics mechanisms involved are complex and not well understood and require more detailed analysis in order to validate both the plasma response and transport modeling tools for use in ITER and future burning plasma devices.