Overview of KSTAR Experimental Research towards Future Fusion Reactors*

KSTAR has been focused on exploring the key physics and engineering issues towards future fusion reactors by demonstrating the long pulse operation of high beta steady-state discharge[1]. Advanced scenarios are developed targeting steady-state operation and significant progress has been made in high beta scenarios with β_N of 3. Abundant fast ions exist in the new operation scenario called FIRE and they play an important role in confinement enhancement FIRE mode may not mean that fast ions fully determine all properties of confinement in the complex fusion plasma system [2]. The optimization of 3D magnetic field techniques including adaptive control and machine learning made long-pulse operation and high performance discharge of ELM suppressed discharge possible [3]. Symmetric multiple shattered pellet injections and real-time DECAF[4] are being conducted in order to mitigate and avoid disruption accompanying high performance for long-pulse ITER-like scenarios in KSTAR.  Lastly, the research plan in near term will be addressed with divertor tungsten upgrades with active cooling and KSTAR is steadily progressing the upgrade of extensive NBI and helicon current drive heating and transition to full metallic wall.