Long Pulse ITER Scenario and Control Development on KSTAR

ORAL

Abstract

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.

*This material is based upon work supported by the US Department of Energy, Office of Science, Office of Fusion Energy Sciences under Award DE-SC0023399. This work was supported by Korean Ministry of Science and ICT under KFE R&D Programs of “KSTAR Experimental Collaboration and Fusion Plasma Research (Grant no. KFE-EN2301-14)”. Disclaimer: This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

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Presenters

  • Nicholas W Eidietis

    • General Atomics

Authors

  • Nicholas W Eidietis

    • General Atomics

  • Jayson L Barr

    • General Atomics - San Diego

  • William Boyes

    • ORAU

  • Sanghee Hahn

    • Korea Institute of Fusion Energy

  • Shira Morosohk

    • Oak Ridge Associated Universities

  • Zichuan A Xing

    • General Atomics

  • Min-ho Woo

    • Korea Institute of Fusion Energy