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arXiv · 2609.30452

Demonstration of H-mode Error Field Identification in a Single Discharge via Island Healing

E. M. Bursch·A. Xie·J. L. Barr·S. K. Kim·N. C. Logan·S. M. Yang·J. G. Bak·W. Choi·Q. Hu·J. W. Juhn·J. Kim·J. Lee·N. Leuthold·J. K. Park·C. Paz-Soldan·L. Piron·G. Seo·J. Seo
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Abstract

Non-disruptive compass scan error field identification via island healing is demonstrated on KSTAR in a single H-mode discharge. This method can allow for up to a 75% reduction in the operational time necessary for a complete compass scan by reducing the required discharges from four to one. Previous experiments on DIII-D, JET, and MAST-U have demonstrated the technique in Ohmic and L-mode but required multiple discharges and strong real-time n=1 magnetics diagnostics close to the plasma that are unlikely to be viable for future devices. The results presented here were made possible by implementing a new set of triggering algorithms relevant to fusion pilot plant operation into the KSTAR plasma control system, along with KSTAR's strong RMPs and long pulse lengths. This represents a significant step towards the disruption-free error field identification method being demonstrated for deployment on future disruption-averse tokamaks, including ITER and fusion pilot plants. Steps needed to close remaining gaps to viability are addressed.

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E. M. Bursch, A. Xie, J. L. Barr, S. K. Kim, N. C. Logan, S. M. Yang, J. G. Bak, W. Choi, Q. Hu, J. W. Juhn, J. Kim, J. Lee, N. Leuthold, J. K. Park, C. Paz-Soldan, L. Piron, G. Seo, J. Seo. 2026-09-24. Demonstration of H-mode Error Field Identification in a Single Discharge via Island Healing. https://arxiv.org/abs/2609.30452

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