Fluid and gyrokinetic simulations of impurity transport at JET

JET-EFDA collaborators

Research output: Contribution to journalArticleScientificpeer-review

27 Citations (Scopus)

Abstract

Impurity transport coefficients due to ion-temperature-gradient (ITG) mode and trapped-electron 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 such as impurity charge number Z, ion logarithmic temperature gradient, collisionality, E × B 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 in 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.
Original languageEnglish
Article number105005
Number of pages13
JournalPlasma Physics and Controlled Fusion
Volume53
Issue number10
DOIs
Publication statusPublished - 2011
MoE publication typeA1 Journal article-refereed

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Impurities
impurities
Fluids
fluids
simulation
Thermal gradients
temperature gradients
ion temperature
Ions
transport properties
profiles
shearing
Shearing
Discharge (fluid mechanics)
hollow
Turbulence
turbulence
injection
saturation
Plasmas

Cite this

@article{a3ab4490394342a78917cc5242b8356a,
title = "Fluid and gyrokinetic simulations of impurity transport at JET",
abstract = "Impurity transport coefficients due to ion-temperature-gradient (ITG) mode and trapped-electron 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 such as impurity charge number Z, ion logarithmic temperature gradient, collisionality, E × B 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 in 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.",
author = "H. Nordman and A. Skyman and P. Strand and C. Giroud and F. Jenko and F. Merz and V. Naulin and Tuomas Tala and {JET-EFDA collaborators}",
year = "2011",
doi = "10.1088/0741-3335/53/10/105005",
language = "English",
volume = "53",
journal = "Plasma Physics and Controlled Fusion",
issn = "0741-3335",
publisher = "Institute of Physics IOP",
number = "10",

}

Fluid and gyrokinetic simulations of impurity transport at JET. / JET-EFDA collaborators.

In: Plasma Physics and Controlled Fusion, Vol. 53, No. 10, 105005, 2011.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Fluid and gyrokinetic simulations of impurity transport at JET

AU - Nordman, H.

AU - Skyman, A.

AU - Strand, P.

AU - Giroud, C.

AU - Jenko, F.

AU - Merz, F.

AU - Naulin, V.

AU - Tala, Tuomas

AU - JET-EFDA collaborators

PY - 2011

Y1 - 2011

N2 - Impurity transport coefficients due to ion-temperature-gradient (ITG) mode and trapped-electron 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 such as impurity charge number Z, ion logarithmic temperature gradient, collisionality, E × B 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 in 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.

AB - Impurity transport coefficients due to ion-temperature-gradient (ITG) mode and trapped-electron 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 such as impurity charge number Z, ion logarithmic temperature gradient, collisionality, E × B 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 in 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.

U2 - 10.1088/0741-3335/53/10/105005

DO - 10.1088/0741-3335/53/10/105005

M3 - Article

VL - 53

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

SN - 0741-3335

IS - 10

M1 - 105005

ER -