Speakers
Description
The KSTAR Neutral Beam Injection (NBI) system plays a crucial role in achieving high-performance, long-pulse plasma operation by providing substantial plasma heating and current drive. It consists of two beamlines, NBI-1 and NBI-2, each equipped with three positive-ion-based ion sources, designed to deliver 2.0 MW of deuterium beam power at an energy of 100 keV. In the 2024 KSTAR campaign, research efforts focused on enhancing the stability and performance of the NBI system while improving real-time control capabilities. Maintenance and optimization of the power and control systems enabled the reliable operation of all six beam sources, ensuring stable plasma experiments. Compared to the previous campaign, an additional 1.5 MW of beam power was simultaneously utilized, significantly contributing to high-performance plasma generation. Furthermore, modifications to the ion source magnetic field configuration increased the fraction of the first energy component, which is expected to enhance plasma heating efficiency. To further advance plasma control in KSTAR, improvements in NBI real-time control performance were implemented. With enhanced operational stability, NBI control operation played a key role in bifurcation studies and MHD avoidance experiments during the 2024 campaign. Additionally, improvements in the PCS-NBI control system enabled the successful commissioning of an NBI feedback control system for normalized beta. This feedback control system is expected to serve as a foundation for future expansions, leading to the development of surrogate model-based NBI heating and current drive control system. In this presentation, the experimental result of the NBI feedback control system conducted during the 2024 KSTAR campaign will be summarized.
