Fluid and gyrokinetic simulations of impurity transport at JET
Journal article, 2011

Impurity transport coefficients due to Ion-Temperature-Gradient (ITG) mode and Trapped-Electron (TE) mode turbulence are calculated using profile data from dedicated impurity injection experiments at JET. Results obtained with a multi-fluid model are compared with quasi-linear and nonlinear gyrokinetic simulation results obtained with the code GENE. The sign of the impurity convective velocity (pinch) and its various contributions are discussed. The dependence of the impurity transport coefficients and impurity peaking factor -∇nZ/nZ on plasma parameters like impurity charge number Z, ion logarithmic temperature gradient, collisionality, ExB shearing, and charge fraction are investigated. It is found that for the studied ITG dominated JET discharges, both the fluid and gyrokinetic results show an increase of the impurity peaking factor for low Z-values followed by a saturation at moderate values of impurity peaking, much below the neoclassical predictions, for large values of Z. The results are in qualitative agreement with the experimental trends observed for the injected impurities (Ne, Ar, Ni) whereas for the background carbon species the observed flat or weakly hollow C profiles are not well reproduced by the simulations.






Hans Nordman

Chalmers, Earth and Space Sciences, Transport Theory

Andreas Skyman

Chalmers, Earth and Space Sciences, Transport Theory

Pär Strand

Chalmers, Earth and Space Sciences, Transport Theory

Carine Giroud

Culham Science Centre

Frank Jenko

Max Planck Society

Culham Science Centre

Florian Merz

Culham Science Centre

Volker Naulin

Culham Science Centre

Tuomas Tala

Culham Science Centre

Plasma Physics and Controlled Fusion

0741-3335 (ISSN) 1361-6587 (eISSN)

Vol. 53 10 105005- 105005

Driving Forces

Sustainable development

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Basic sciences

Subject Categories

Fusion, Plasma and Space Physics



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