1. Gyrokinetic prediction of core tungsten peaking in a WEST plasma with nitrogen impurities
- Author
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Dominski, J., Maget, P., Manas, O., Morales, J., Ku, S., Scheinberg, A., Chang, C. S., Hager, R., O'Mullane, M., and team, the WEST
- Subjects
Physics - Plasma Physics - Abstract
Tungsten peaking is predicted in the core of a WEST plasma with total-f gyrokinetic simulations, including both collisional and turbulent transport. This prediction is validated with a synthetic diagnostic of the bolometry. Although nitrogen impurities are shown to reduce the neoclassical peaking of tungsten on-axis, the overall tungsten peaking increases when nitrogen impurities are present, as they reduce the turbulence screening off-axis. This finding is important for the plasma current ramp-up phase of ITER, where light impurities seeding will be desirable to achieve low temperatures at the plasma-facing components and reduce tungsten sputtering. It provides further argument for applying early ECRH heating to maintain margins on the core power balance. The neoclassical peaking factor is cross-verified between XGC and FACIT. The heat flux at separatrix and the heat load width are modeled by XGC and compared to WEST data., Comment: 15 pages, 17 figures
- Published
- 2024