Long Pulse ITER Scenario and Control Development on KSTAR*

Development of the long-pulse ITER baseline scenario (IBS) and advanced inductive (or "hybrid") scenarios and supporting control is reported. The 2023 installation of an ITER-like lower tungsten divertor in KSTAR requires re-assessment of existing ITER scenarios. IBS development focuses upon defining and executing KSTAR-scaled ITER-like ramp-up and ramp-down. Hybrid development focuses upon developing access to and verifying the existence of the scenario with the tungsten divertor. The first application of new control developments, including a Proximity Controller (PC) to aid in continuous disruption prevention and upgrades to the existing Real-Time Feed-Forward (RTFF) algorithm for robust and reliable shape control during long-pulse sustainment and ramp-down, are reported. The PC calculates proximity to known stability limits and guides the plasma state away from those limits. First application of the PC is to density limit event avoidance. The RTFF algorithm regularly updates the feed-forward coil current targets based on changing plasma conditions, including resistivity and target shape changes. This aids flattop maintenance, as well as both scheduled and un-scheduled ramp-downs.