Gyrokinetic prediction of core tungsten peaking in a WEST plasma with nitrogen impurities

Autor: J. Dominski, P. Maget, P. Manas, J. Morales, S. Ku, A. Scheinberg, C.S. Chang, R. Hager, M. O’Mullane, the WEST team
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Nuclear Fusion, Vol 65, Iss 1, p 016003 (2024)
Druh dokumentu: article
ISSN: 1741-4326
0029-5515
37175963
DOI: 10.1088/1741-4326/ad8c63
Popis: 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.
Databáze: Directory of Open Access Journals