Fluid and gyrokinetic simulations of impurity transport at JET

JET-EFDA collaborators

    Research output: Contribution to journalArticleScientificpeer-review

    28 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 -