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

Fuente: arXiv
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Main Authors: Dominski, J., Maget, P., Manas, O., Morales, J., Ku, S., Scheinberg, A., Chang, C. S., Hager, R., O'Mullane, M., team, the WEST
Format: Preprint
Published: 2024
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author Dominski, J.
Maget, P.
Manas, O.
Morales, J.
Ku, S.
Scheinberg, A.
Chang, C. S.
Hager, R.
O'Mullane, M.
team, the WEST
author_facet Dominski, J.
Maget, P.
Manas, O.
Morales, J.
Ku, S.
Scheinberg, A.
Chang, C. S.
Hager, R.
O'Mullane, M.
team, the WEST
contents 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.
format Preprint
id arxiv_https___arxiv_org_abs_2410_14432
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Gyrokinetic prediction of core tungsten peaking in a WEST plasma with nitrogen impurities
Dominski, J.
Maget, P.
Manas, O.
Morales, J.
Ku, S.
Scheinberg, A.
Chang, C. S.
Hager, R.
O'Mullane, M.
team, the WEST
Plasma Physics
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.
title Gyrokinetic prediction of core tungsten peaking in a WEST plasma with nitrogen impurities
topic Plasma Physics
url https://arxiv.org/abs/2410.14432