Core transport properties in JT-60U and JET identity plasmas

ITPA Transport & Confinement Topical Group, JT-60 Team, JET-EFDA collaborators

    Research output: Contribution to journalArticleScientificpeer-review

    9 Citations (Scopus)

    Abstract

    The paper compares the transport properties of a set of dimensionless identity experiments performed between JET and JT-60U in the advanced tokamak regime with internal transport barrier, ITB. These International Tokamak Physics Activity, ITPA, joint experiments were carried out with the same plasma shape, toroidal magnetic field ripple and dimensionless profiles as close as possible during the ITB triggering phase in terms of safety factor, normalized Larmor radius, normalized collision frequency, thermal beta, ratio of ion to electron temperatures. Similarities in the ITB triggering mechanisms and sustainment were observed when a good match was achieved of the most relevant normalized profiles except the toroidal Mach number. Similar thermal ion transport levels in the two devices have been measured in either monotonic or non-monotonic q-profiles. In contrast, differences between JET and JT-60U were observed on the electron thermal and particle confinement in reversed magnetic shear configurations. It was found that the larger shear reversal in the very centre (inside normalized radius of 0.2) of JT-60U plasmas allowed the sustainment of stronger electron density ITBs compared with JET. As a consequence of peaked density profile, the core bootstrap current density is more than five times higher in JT-60U compared with JET. Thanks to the bootstrap effect and the slightly broader neutral beam deposition, reversed magnetic shear configurations are self-sustained in JT-60U scenarios. Analyses of similarities and differences between the two devices address key questions on the validity of the usual assumptions made in ITER steady scenario modelling, e.g. a flat density profile in the core with thermal transport barrier? Such assumptions have consequences on the prediction of fusion performance, bootstrap current and on the sustainment of the scenario.

    Original languageEnglish
    Article number073020
    Number of pages13
    JournalNuclear Fusion
    Volume51
    Issue number7
    DOIs
    Publication statusPublished - 1 Jul 2011
    MoE publication typeNot Eligible

    Fingerprint

    transport properties
    profiles
    shear
    safety factors
    Larmor radius
    neutral beams
    configurations
    ripples
    Mach number
    ions
    fusion
    electron energy
    current density
    physics
    collisions
    radii
    predictions
    magnetic fields
    electrons

    Cite this

    ITPA Transport & Confinement Topical Group, JT-60 Team, & JET-EFDA collaborators (2011). Core transport properties in JT-60U and JET identity plasmas. Nuclear Fusion, 51(7), [073020]. https://doi.org/10.1088/0029-5515/51/7/073020
    ITPA Transport & Confinement Topical Group ; JT-60 Team ; JET-EFDA collaborators. / Core transport properties in JT-60U and JET identity plasmas. In: Nuclear Fusion. 2011 ; Vol. 51, No. 7.
    @article{161bbab7e2c741cd936a89f3b8c9e9fb,
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    abstract = "The paper compares the transport properties of a set of dimensionless identity experiments performed between JET and JT-60U in the advanced tokamak regime with internal transport barrier, ITB. These International Tokamak Physics Activity, ITPA, joint experiments were carried out with the same plasma shape, toroidal magnetic field ripple and dimensionless profiles as close as possible during the ITB triggering phase in terms of safety factor, normalized Larmor radius, normalized collision frequency, thermal beta, ratio of ion to electron temperatures. Similarities in the ITB triggering mechanisms and sustainment were observed when a good match was achieved of the most relevant normalized profiles except the toroidal Mach number. Similar thermal ion transport levels in the two devices have been measured in either monotonic or non-monotonic q-profiles. In contrast, differences between JET and JT-60U were observed on the electron thermal and particle confinement in reversed magnetic shear configurations. It was found that the larger shear reversal in the very centre (inside normalized radius of 0.2) of JT-60U plasmas allowed the sustainment of stronger electron density ITBs compared with JET. As a consequence of peaked density profile, the core bootstrap current density is more than five times higher in JT-60U compared with JET. Thanks to the bootstrap effect and the slightly broader neutral beam deposition, reversed magnetic shear configurations are self-sustained in JT-60U scenarios. Analyses of similarities and differences between the two devices address key questions on the validity of the usual assumptions made in ITER steady scenario modelling, e.g. a flat density profile in the core with thermal transport barrier? Such assumptions have consequences on the prediction of fusion performance, bootstrap current and on the sustainment of the scenario.",
    author = "X. Litaudon and Y. Sakamoto and {de Vries}, {P. C.} and Antti Salmi and Tuomas Tala and C. Angioni and S. Benkadda and M. Beurskens and C. Bourdelle and M. Brix and K. Cromb{\'e} and T. Fujita and S. Futatani and X Garbet and C. Giroud and Hawkes, {N. C.} and N. Hayashi and Hoang, {G. T.} and Hogeweij, {G. M.D.} and G. Matsunaga and T. Nakano and N. Oyama and V. Parail and K. Shinohara and T. Suzuki and M. Takechi and H. Takenaga and T. Takizuka and H. Urano and I. Voitsekhovitch and M. Yoshida and {ITPA Transport & Confinement Topical Group} and {JT-60 Team} and {JET-EFDA collaborators}",
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    ITPA Transport & Confinement Topical Group, JT-60 Team & JET-EFDA collaborators 2011, 'Core transport properties in JT-60U and JET identity plasmas', Nuclear Fusion, vol. 51, no. 7, 073020. https://doi.org/10.1088/0029-5515/51/7/073020

    Core transport properties in JT-60U and JET identity plasmas. / ITPA Transport & Confinement Topical Group; JT-60 Team; JET-EFDA collaborators.

    In: Nuclear Fusion, Vol. 51, No. 7, 073020, 01.07.2011.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Core transport properties in JT-60U and JET identity plasmas

    AU - Litaudon, X.

    AU - Sakamoto, Y.

    AU - de Vries, P. C.

    AU - Salmi, Antti

    AU - Tala, Tuomas

    AU - Angioni, C.

    AU - Benkadda, S.

    AU - Beurskens, M.

    AU - Bourdelle, C.

    AU - Brix, M.

    AU - Crombé, K.

    AU - Fujita, T.

    AU - Futatani, S.

    AU - Garbet, X

    AU - Giroud, C.

    AU - Hawkes, N. C.

    AU - Hayashi, N.

    AU - Hoang, G. T.

    AU - Hogeweij, G. M.D.

    AU - Matsunaga, G.

    AU - Nakano, T.

    AU - Oyama, N.

    AU - Parail, V.

    AU - Shinohara, K.

    AU - Suzuki, T.

    AU - Takechi, M.

    AU - Takenaga, H.

    AU - Takizuka, T.

    AU - Urano, H.

    AU - Voitsekhovitch, I.

    AU - Yoshida, M.

    AU - ITPA Transport & Confinement Topical Group

    AU - JT-60 Team

    AU - JET-EFDA collaborators

    PY - 2011/7/1

    Y1 - 2011/7/1

    N2 - The paper compares the transport properties of a set of dimensionless identity experiments performed between JET and JT-60U in the advanced tokamak regime with internal transport barrier, ITB. These International Tokamak Physics Activity, ITPA, joint experiments were carried out with the same plasma shape, toroidal magnetic field ripple and dimensionless profiles as close as possible during the ITB triggering phase in terms of safety factor, normalized Larmor radius, normalized collision frequency, thermal beta, ratio of ion to electron temperatures. Similarities in the ITB triggering mechanisms and sustainment were observed when a good match was achieved of the most relevant normalized profiles except the toroidal Mach number. Similar thermal ion transport levels in the two devices have been measured in either monotonic or non-monotonic q-profiles. In contrast, differences between JET and JT-60U were observed on the electron thermal and particle confinement in reversed magnetic shear configurations. It was found that the larger shear reversal in the very centre (inside normalized radius of 0.2) of JT-60U plasmas allowed the sustainment of stronger electron density ITBs compared with JET. As a consequence of peaked density profile, the core bootstrap current density is more than five times higher in JT-60U compared with JET. Thanks to the bootstrap effect and the slightly broader neutral beam deposition, reversed magnetic shear configurations are self-sustained in JT-60U scenarios. Analyses of similarities and differences between the two devices address key questions on the validity of the usual assumptions made in ITER steady scenario modelling, e.g. a flat density profile in the core with thermal transport barrier? Such assumptions have consequences on the prediction of fusion performance, bootstrap current and on the sustainment of the scenario.

    AB - The paper compares the transport properties of a set of dimensionless identity experiments performed between JET and JT-60U in the advanced tokamak regime with internal transport barrier, ITB. These International Tokamak Physics Activity, ITPA, joint experiments were carried out with the same plasma shape, toroidal magnetic field ripple and dimensionless profiles as close as possible during the ITB triggering phase in terms of safety factor, normalized Larmor radius, normalized collision frequency, thermal beta, ratio of ion to electron temperatures. Similarities in the ITB triggering mechanisms and sustainment were observed when a good match was achieved of the most relevant normalized profiles except the toroidal Mach number. Similar thermal ion transport levels in the two devices have been measured in either monotonic or non-monotonic q-profiles. In contrast, differences between JET and JT-60U were observed on the electron thermal and particle confinement in reversed magnetic shear configurations. It was found that the larger shear reversal in the very centre (inside normalized radius of 0.2) of JT-60U plasmas allowed the sustainment of stronger electron density ITBs compared with JET. As a consequence of peaked density profile, the core bootstrap current density is more than five times higher in JT-60U compared with JET. Thanks to the bootstrap effect and the slightly broader neutral beam deposition, reversed magnetic shear configurations are self-sustained in JT-60U scenarios. Analyses of similarities and differences between the two devices address key questions on the validity of the usual assumptions made in ITER steady scenario modelling, e.g. a flat density profile in the core with thermal transport barrier? Such assumptions have consequences on the prediction of fusion performance, bootstrap current and on the sustainment of the scenario.

    U2 - 10.1088/0029-5515/51/7/073020

    DO - 10.1088/0029-5515/51/7/073020

    M3 - Article

    AN - SCOPUS:79960379497

    VL - 51

    JO - Nuclear Fusion

    JF - Nuclear Fusion

    SN - 0029-5515

    IS - 7

    M1 - 073020

    ER -

    ITPA Transport & Confinement Topical Group, JT-60 Team, JET-EFDA collaborators. Core transport properties in JT-60U and JET identity plasmas. Nuclear Fusion. 2011 Jul 1;51(7). 073020. https://doi.org/10.1088/0029-5515/51/7/073020