KSTAR Overview

W.H. Ko, (E. Schuster), et al. (Collaboration Paper)

Division of Plasma Physics (DPP) Annual Meeting of the American Physical Society (APS)

Spokane, WA, USA, October 17-21, 2022

Abstract

KSTAR focused on exploring the key physics and engineering issues of the high beta steady-state operation for ITER and future fusion reactors utilizing unique capabilities of KSTAR. Most of all, an advanced scenario was developed targeting steady-state operation and significant progress h as been made in shape and heating control to address the stationary high ion temperature, hybrid, double barrier and high beta scenario with beta_N~3 and newly observed I-mode-like regime. KSTAR advanced operation scenario have shown that the electron cyclotron current drive mitigated and suppressed the beam-ion driven toroidal Alfv´en eigenmodes (TAEs) for over several tens of global energy confinement time.

Symmetric multiple Shattered Pellet Injections (SPIs) for ITER disruption mitigation operation uniquely demonstrated for its performance in KSTAR. The real time DECAF (Disruption Event Characterization and Forecasting) validated the real time disruption event characterization and forecasting events on KSTAR.

In recent KSTAR 3D magnetic field experiments, ELM optimization and automatic control techniques such as adapted ELM controller and Machine Learning algorithm in order to suppress ELM successfully implemented in KSTAR PCS. Machine learning algorithm successfully suppressed nearly complete ELM-crash with the first ELM. Machine learning, adaptive ELM controller and ERMPs applied to RMP-driven ELM suppression experiments with long pulses for ITER operation.

To enhance understanding of the fundamental processes, the KSTAR research also focused on interaction of island and turbulence in pedestal with complexity-enthropy and the dynamics of turbulence based on broadband ECE diagnostics.

*This research was supported by R&D Program of "KSTAR Experimental Collaboration and Fusion Plasma Research (EN2201-12)" through the Korea Institute of Fusion Energy (KFE) funded by Korea Ministry of Science and ICT (MSIT).