Transport modelling and gyrokinetic analysis of advanced high performance discharges

J.E. Kinsey, F. Imbeaux, G.M. Staebler, R. Budny, C. Bourdelle, A. Fukuyama, X. Garbet, Tuomas Tala, V. Parail

    Research output: Contribution to journalArticleScientificpeer-review

    15 Citations (Scopus)

    Abstract

    Predictive transport modelling and gyrokinetic stability analyses of demonstration hybrid (HYBRID) and advanced tokamak (AT) discharges from the International Tokamak Physics Activity (ITPA) profile database are presented. Both regimes have exhibited enhanced core confinement (above the conventional ITER reference H-mode scenario) but differ in their current density profiles. Recent contributions to the ITPA database have facilitated an effort to study the underlying physics governing confinement in these advanced scenarios. In this paper, we assess the level of commonality of the turbulent transport physics and the relative roles of the transport suppression mechanisms (i.e. E × B shear and Shafranov shift (α) stabilization) using data for select HYBRID and AT discharges from the DIII-D, JET and AUG tokamaks. GLF23 transport modelling and gyrokinetic stability analysis indicate that E × B shear and Shafranov shift stabilization play essential roles in producing the improved core confinement in both HYBRID and AT discharges. Shafranov shift stabilization is found to be more important in AT discharges than in HYBRID discharges. We have also examined the competition between the stabilizing effects of E × B shear and Shafranov shift stabilization and the destabilizing effects of higher safety factors and parallel velocity shear. Linear and nonlinear gyrokinetic simulations of idealized low and high safety factor cases reveal some interesting consequences. A low safety factor (i.e. HYBRID relevant) is directly beneficial in reducing the transport, and E × B shear stabilization can dominate parallel velocity shear destabilization allowing the turbulence to be quenched. However, at low-q/high current, Shafranov shift stabilization plays less of a role. Higher safety factors (as found in AT discharges), on the other hand, have larger amounts of Shafranov shift stabilization, but parallel velocity shear destabilization can prevent E × B shear quenching of the turbulent transport, and only E × B suppression is achieved.
    Original languageEnglish
    Pages (from-to)450 - 458
    Number of pages9
    JournalNuclear Fusion
    Volume45
    Issue number6
    DOIs
    Publication statusPublished - 2005
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    shear
    stabilization
    safety factors
    shift
    physics
    destabilization
    retarding
    commonality
    profiles
    high current
    turbulence
    quenching
    current density
    simulation

    Keywords

    • JET
    • plasma
    • fusion energy
    • fusion reactors
    • ITER
    • Tokamak

    Cite this

    Kinsey, J. E., Imbeaux, F., Staebler, G. M., Budny, R., Bourdelle, C., Fukuyama, A., ... Parail, V. (2005). Transport modelling and gyrokinetic analysis of advanced high performance discharges. Nuclear Fusion, 45(6), 450 - 458. https://doi.org/10.1088/0029-5515/45/6/006
    Kinsey, J.E. ; Imbeaux, F. ; Staebler, G.M. ; Budny, R. ; Bourdelle, C. ; Fukuyama, A. ; Garbet, X. ; Tala, Tuomas ; Parail, V. / Transport modelling and gyrokinetic analysis of advanced high performance discharges. In: Nuclear Fusion. 2005 ; Vol. 45, No. 6. pp. 450 - 458.
    @article{5de8a398c0d74438867700f8e97efb28,
    title = "Transport modelling and gyrokinetic analysis of advanced high performance discharges",
    abstract = "Predictive transport modelling and gyrokinetic stability analyses of demonstration hybrid (HYBRID) and advanced tokamak (AT) discharges from the International Tokamak Physics Activity (ITPA) profile database are presented. Both regimes have exhibited enhanced core confinement (above the conventional ITER reference H-mode scenario) but differ in their current density profiles. Recent contributions to the ITPA database have facilitated an effort to study the underlying physics governing confinement in these advanced scenarios. In this paper, we assess the level of commonality of the turbulent transport physics and the relative roles of the transport suppression mechanisms (i.e. E × B shear and Shafranov shift (α) stabilization) using data for select HYBRID and AT discharges from the DIII-D, JET and AUG tokamaks. GLF23 transport modelling and gyrokinetic stability analysis indicate that E × B shear and Shafranov shift stabilization play essential roles in producing the improved core confinement in both HYBRID and AT discharges. Shafranov shift stabilization is found to be more important in AT discharges than in HYBRID discharges. We have also examined the competition between the stabilizing effects of E × B shear and Shafranov shift stabilization and the destabilizing effects of higher safety factors and parallel velocity shear. Linear and nonlinear gyrokinetic simulations of idealized low and high safety factor cases reveal some interesting consequences. A low safety factor (i.e. HYBRID relevant) is directly beneficial in reducing the transport, and E × B shear stabilization can dominate parallel velocity shear destabilization allowing the turbulence to be quenched. However, at low-q/high current, Shafranov shift stabilization plays less of a role. Higher safety factors (as found in AT discharges), on the other hand, have larger amounts of Shafranov shift stabilization, but parallel velocity shear destabilization can prevent E × B shear quenching of the turbulent transport, and only E × B suppression is achieved.",
    keywords = "JET, plasma, fusion energy, fusion reactors, ITER, Tokamak",
    author = "J.E. Kinsey and F. Imbeaux and G.M. Staebler and R. Budny and C. Bourdelle and A. Fukuyama and X. Garbet and Tuomas Tala and V. Parail",
    year = "2005",
    doi = "10.1088/0029-5515/45/6/006",
    language = "English",
    volume = "45",
    pages = "450 -- 458",
    journal = "Nuclear Fusion",
    issn = "0029-5515",
    publisher = "Institute of Physics IOP",
    number = "6",

    }

    Kinsey, JE, Imbeaux, F, Staebler, GM, Budny, R, Bourdelle, C, Fukuyama, A, Garbet, X, Tala, T & Parail, V 2005, 'Transport modelling and gyrokinetic analysis of advanced high performance discharges', Nuclear Fusion, vol. 45, no. 6, pp. 450 - 458. https://doi.org/10.1088/0029-5515/45/6/006

    Transport modelling and gyrokinetic analysis of advanced high performance discharges. / Kinsey, J.E.; Imbeaux, F.; Staebler, G.M.; Budny, R.; Bourdelle, C.; Fukuyama, A.; Garbet, X.; Tala, Tuomas; Parail, V.

    In: Nuclear Fusion, Vol. 45, No. 6, 2005, p. 450 - 458.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Transport modelling and gyrokinetic analysis of advanced high performance discharges

    AU - Kinsey, J.E.

    AU - Imbeaux, F.

    AU - Staebler, G.M.

    AU - Budny, R.

    AU - Bourdelle, C.

    AU - Fukuyama, A.

    AU - Garbet, X.

    AU - Tala, Tuomas

    AU - Parail, V.

    PY - 2005

    Y1 - 2005

    N2 - Predictive transport modelling and gyrokinetic stability analyses of demonstration hybrid (HYBRID) and advanced tokamak (AT) discharges from the International Tokamak Physics Activity (ITPA) profile database are presented. Both regimes have exhibited enhanced core confinement (above the conventional ITER reference H-mode scenario) but differ in their current density profiles. Recent contributions to the ITPA database have facilitated an effort to study the underlying physics governing confinement in these advanced scenarios. In this paper, we assess the level of commonality of the turbulent transport physics and the relative roles of the transport suppression mechanisms (i.e. E × B shear and Shafranov shift (α) stabilization) using data for select HYBRID and AT discharges from the DIII-D, JET and AUG tokamaks. GLF23 transport modelling and gyrokinetic stability analysis indicate that E × B shear and Shafranov shift stabilization play essential roles in producing the improved core confinement in both HYBRID and AT discharges. Shafranov shift stabilization is found to be more important in AT discharges than in HYBRID discharges. We have also examined the competition between the stabilizing effects of E × B shear and Shafranov shift stabilization and the destabilizing effects of higher safety factors and parallel velocity shear. Linear and nonlinear gyrokinetic simulations of idealized low and high safety factor cases reveal some interesting consequences. A low safety factor (i.e. HYBRID relevant) is directly beneficial in reducing the transport, and E × B shear stabilization can dominate parallel velocity shear destabilization allowing the turbulence to be quenched. However, at low-q/high current, Shafranov shift stabilization plays less of a role. Higher safety factors (as found in AT discharges), on the other hand, have larger amounts of Shafranov shift stabilization, but parallel velocity shear destabilization can prevent E × B shear quenching of the turbulent transport, and only E × B suppression is achieved.

    AB - Predictive transport modelling and gyrokinetic stability analyses of demonstration hybrid (HYBRID) and advanced tokamak (AT) discharges from the International Tokamak Physics Activity (ITPA) profile database are presented. Both regimes have exhibited enhanced core confinement (above the conventional ITER reference H-mode scenario) but differ in their current density profiles. Recent contributions to the ITPA database have facilitated an effort to study the underlying physics governing confinement in these advanced scenarios. In this paper, we assess the level of commonality of the turbulent transport physics and the relative roles of the transport suppression mechanisms (i.e. E × B shear and Shafranov shift (α) stabilization) using data for select HYBRID and AT discharges from the DIII-D, JET and AUG tokamaks. GLF23 transport modelling and gyrokinetic stability analysis indicate that E × B shear and Shafranov shift stabilization play essential roles in producing the improved core confinement in both HYBRID and AT discharges. Shafranov shift stabilization is found to be more important in AT discharges than in HYBRID discharges. We have also examined the competition between the stabilizing effects of E × B shear and Shafranov shift stabilization and the destabilizing effects of higher safety factors and parallel velocity shear. Linear and nonlinear gyrokinetic simulations of idealized low and high safety factor cases reveal some interesting consequences. A low safety factor (i.e. HYBRID relevant) is directly beneficial in reducing the transport, and E × B shear stabilization can dominate parallel velocity shear destabilization allowing the turbulence to be quenched. However, at low-q/high current, Shafranov shift stabilization plays less of a role. Higher safety factors (as found in AT discharges), on the other hand, have larger amounts of Shafranov shift stabilization, but parallel velocity shear destabilization can prevent E × B shear quenching of the turbulent transport, and only E × B suppression is achieved.

    KW - JET

    KW - plasma

    KW - fusion energy

    KW - fusion reactors

    KW - ITER

    KW - Tokamak

    U2 - 10.1088/0029-5515/45/6/006

    DO - 10.1088/0029-5515/45/6/006

    M3 - Article

    VL - 45

    SP - 450

    EP - 458

    JO - Nuclear Fusion

    JF - Nuclear Fusion

    SN - 0029-5515

    IS - 6

    ER -

    Kinsey JE, Imbeaux F, Staebler GM, Budny R, Bourdelle C, Fukuyama A et al. Transport modelling and gyrokinetic analysis of advanced high performance discharges. Nuclear Fusion. 2005;45(6):450 - 458. https://doi.org/10.1088/0029-5515/45/6/006