Radial electric field in JET advanced tokamak scenarios with toroidal field ripple

K. Crombé, Y. Andrew, T.M. Biewer, E. Blanco, P.C. De Vries, C. Giroud, N.C. Hawkes, A. Meigs, Tuomas Tala, M. Von Hellermann, K.-D. Zastrow, J. Efda

    Research output: Contribution to journalArticleScientificpeer-review

    12 Citations (Scopus)

    Abstract

    A dedicated campaign has been run on JET to study the effect of toroidal field (TF) ripple on plasma performance. Radial electric field measurements from experiments on a series of plasmas with internal transport barriers (ITBs) and different levels of ripple amplitude are presented. They have been calculated from charge exchange measurements of impurity ion temperature, density and rotation velocity profiles, using the force balance equation. The ion temperature and the toroidal and poloidal rotation velocities are compared in plasmas with both reversed and optimized magnetic shear profiles. Poloidal rotation velocity (vθ) in the ITB region is measured to be of the order of a few tens of km s−1, significantly larger than the neoclassical predictions. Increasing levels of the TF ripple are found to decrease the ion temperature gradient in the ITB region, a measure for the quality of the ITB, and the maximum value of vθ is reduced. The poloidal rotation term dominates in the calculations of the total radial electric field (Er), with the largest gradient in Er measured in the radial region coinciding with the ITB.
    Original languageEnglish
    JournalPlasma Physics and Controlled Fusion
    Volume51
    Issue number5
    DOIs
    Publication statusPublished - 2009
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    ripples
    Electric fields
    ion temperature
    electric fields
    Plasmas
    Ions
    Electric field measurement
    Thermal gradients
    Ion exchange
    charge exchange
    Impurities
    temperature gradients
    Temperature
    velocity distribution
    shear
    impurities
    gradients
    profiles
    predictions
    Experiments

    Keywords

    • plasma toroidal confinement
    • toroidal field ripple
    • plasma
    • plasma transport processes
    • plasma turbulence
    • Tokamak
    • JET

    Cite this

    Crombé, K., Andrew, Y., Biewer, T. M., Blanco, E., De Vries, P. C., Giroud, C., ... Efda, J. (2009). Radial electric field in JET advanced tokamak scenarios with toroidal field ripple. Plasma Physics and Controlled Fusion, 51(5). https://doi.org/10.1088/0741-3335/51/5/055005
    Crombé, K. ; Andrew, Y. ; Biewer, T.M. ; Blanco, E. ; De Vries, P.C. ; Giroud, C. ; Hawkes, N.C. ; Meigs, A. ; Tala, Tuomas ; Von Hellermann, M. ; Zastrow, K.-D. ; Efda, J. / Radial electric field in JET advanced tokamak scenarios with toroidal field ripple. In: Plasma Physics and Controlled Fusion. 2009 ; Vol. 51, No. 5.
    @article{b34563e814074fb7bf7db0210479c8f2,
    title = "Radial electric field in JET advanced tokamak scenarios with toroidal field ripple",
    abstract = "A dedicated campaign has been run on JET to study the effect of toroidal field (TF) ripple on plasma performance. Radial electric field measurements from experiments on a series of plasmas with internal transport barriers (ITBs) and different levels of ripple amplitude are presented. They have been calculated from charge exchange measurements of impurity ion temperature, density and rotation velocity profiles, using the force balance equation. The ion temperature and the toroidal and poloidal rotation velocities are compared in plasmas with both reversed and optimized magnetic shear profiles. Poloidal rotation velocity (vθ) in the ITB region is measured to be of the order of a few tens of km s−1, significantly larger than the neoclassical predictions. Increasing levels of the TF ripple are found to decrease the ion temperature gradient in the ITB region, a measure for the quality of the ITB, and the maximum value of vθ is reduced. The poloidal rotation term dominates in the calculations of the total radial electric field (Er), with the largest gradient in Er measured in the radial region coinciding with the ITB.",
    keywords = "plasma toroidal confinement, toroidal field ripple, plasma, plasma transport processes, plasma turbulence, Tokamak, JET",
    author = "K. Cromb{\'e} and Y. Andrew and T.M. Biewer and E. Blanco and {De Vries}, P.C. and C. Giroud and N.C. Hawkes and A. Meigs and Tuomas Tala and {Von Hellermann}, M. and K.-D. Zastrow and J. Efda",
    year = "2009",
    doi = "10.1088/0741-3335/51/5/055005",
    language = "English",
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    journal = "Plasma Physics and Controlled Fusion",
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    Crombé, K, Andrew, Y, Biewer, TM, Blanco, E, De Vries, PC, Giroud, C, Hawkes, NC, Meigs, A, Tala, T, Von Hellermann, M, Zastrow, K-D & Efda, J 2009, 'Radial electric field in JET advanced tokamak scenarios with toroidal field ripple', Plasma Physics and Controlled Fusion, vol. 51, no. 5. https://doi.org/10.1088/0741-3335/51/5/055005

    Radial electric field in JET advanced tokamak scenarios with toroidal field ripple. / Crombé, K.; Andrew, Y.; Biewer, T.M.; Blanco, E.; De Vries, P.C.; Giroud, C.; Hawkes, N.C.; Meigs, A.; Tala, Tuomas; Von Hellermann, M.; Zastrow, K.-D.; Efda, J.

    In: Plasma Physics and Controlled Fusion, Vol. 51, No. 5, 2009.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Radial electric field in JET advanced tokamak scenarios with toroidal field ripple

    AU - Crombé, K.

    AU - Andrew, Y.

    AU - Biewer, T.M.

    AU - Blanco, E.

    AU - De Vries, P.C.

    AU - Giroud, C.

    AU - Hawkes, N.C.

    AU - Meigs, A.

    AU - Tala, Tuomas

    AU - Von Hellermann, M.

    AU - Zastrow, K.-D.

    AU - Efda, J.

    PY - 2009

    Y1 - 2009

    N2 - A dedicated campaign has been run on JET to study the effect of toroidal field (TF) ripple on plasma performance. Radial electric field measurements from experiments on a series of plasmas with internal transport barriers (ITBs) and different levels of ripple amplitude are presented. They have been calculated from charge exchange measurements of impurity ion temperature, density and rotation velocity profiles, using the force balance equation. The ion temperature and the toroidal and poloidal rotation velocities are compared in plasmas with both reversed and optimized magnetic shear profiles. Poloidal rotation velocity (vθ) in the ITB region is measured to be of the order of a few tens of km s−1, significantly larger than the neoclassical predictions. Increasing levels of the TF ripple are found to decrease the ion temperature gradient in the ITB region, a measure for the quality of the ITB, and the maximum value of vθ is reduced. The poloidal rotation term dominates in the calculations of the total radial electric field (Er), with the largest gradient in Er measured in the radial region coinciding with the ITB.

    AB - A dedicated campaign has been run on JET to study the effect of toroidal field (TF) ripple on plasma performance. Radial electric field measurements from experiments on a series of plasmas with internal transport barriers (ITBs) and different levels of ripple amplitude are presented. They have been calculated from charge exchange measurements of impurity ion temperature, density and rotation velocity profiles, using the force balance equation. The ion temperature and the toroidal and poloidal rotation velocities are compared in plasmas with both reversed and optimized magnetic shear profiles. Poloidal rotation velocity (vθ) in the ITB region is measured to be of the order of a few tens of km s−1, significantly larger than the neoclassical predictions. Increasing levels of the TF ripple are found to decrease the ion temperature gradient in the ITB region, a measure for the quality of the ITB, and the maximum value of vθ is reduced. The poloidal rotation term dominates in the calculations of the total radial electric field (Er), with the largest gradient in Er measured in the radial region coinciding with the ITB.

    KW - plasma toroidal confinement

    KW - toroidal field ripple

    KW - plasma

    KW - plasma transport processes

    KW - plasma turbulence

    KW - Tokamak

    KW - JET

    U2 - 10.1088/0741-3335/51/5/055005

    DO - 10.1088/0741-3335/51/5/055005

    M3 - Article

    VL - 51

    JO - Plasma Physics and Controlled Fusion

    JF - Plasma Physics and Controlled Fusion

    SN - 0741-3335

    IS - 5

    ER -