Develop a W-compatible solution for accessing an ELM-suppressed steady-state hybrid scenario
2025 Research Campaign, Task Force: W Compatible Steady State Scenarios
Purpose of Experiment
This experiment aims to develop a tungsten (W)-compatible, ELM-suppressed steady-state hybrid scenario on DIII-D, targeting applicability to long-pulse operations in KSTAR and ITER/FPP. Based on prior success in reproducing a KSTAR-compatible hybrid scenario in DIII-D, the new experiment aims to address the remaining challenges posed by intrinsic W-impurity after diverting and to stabilize type-I ELM suppression using resonant magnetic perturbations (RMP).
Experimental Approach
The plan includes using W laser blow-off (LBO) to mimic intrinsic impurity source and optimizing early electron cyclotron heating (ECH) to prevent impurity accumulation, enabling access to high-confinement hybrid scenarios. In addition, dedicate scans of RMP amplitude, phasing, and q95 to identify robust ELM-suppressed windows in this hybrid scenario. Integration of RMP and W-LBO will also explore the impact of 3D fields on impurity behavior. The expected outcome is a validated, impurity-tolerant hybrid scenario that maintains high performance (βN ~ 3.2, H98 > 1.2), advancing the path toward steady-state fusion operation in ITER and future tokamak devices.
See more details, including project leads, at U.S. Department of Energy, Office of Scientific and Technical Information (OSTI).