Effect of ELMs on rotation and momentum confinement in H-mode discharges in JET

JET-EFDA collaborators

    Research output: Contribution to journalArticleScientificpeer-review

    16 Citations (Scopus)

    Abstract

    The loss of plasma toroidal angular momentum and thermal energy by edge localized modes (ELMs) has been studied in JET. The analysis shows a consistently larger drop in momentum in comparison with the energy loss associated with the ELMs. This difference originates from the large reduction in angular frequency at the plasma edge, observed to penetrate into the plasma up to r/a ~ 0.65 during large type-I ELMs. As a result, the time averaged angular frequency is lowered near the top of the pedestal with increasing ELM frequency, resulting in a significant drop in thermal Mach number at the edge. An increase in profile peaking of ion temperature and angular frequency is observed. At the same time the plasma confinement is reduced while the ratio of confinement times (Rτ = τE) increases noticeably with ELM frequency. This change could be explained by the relatively larger ELM induced losses for momentum in combination with the observed longer build-up time for the momentum density at the plasma edge.
    Original languageEnglish
    Article number045014
    Number of pages12
    JournalPlasma Physics and Controlled Fusion
    Volume52
    Issue number4
    DOIs
    Publication statusPublished - 2010
    MoE publication typeA1 Journal article-refereed

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    Momentum
    momentum
    Plasmas
    Plasma confinement
    Angular momentum
    Thermal energy
    Mach number
    Energy dissipation
    Ions
    plasma control
    toroidal plasmas
    ion temperature
    thermal energy
    angular momentum
    energy dissipation
    kinetic energy
    Temperature
    profiles

    Cite this

    @article{34fc68993c974f52a9383905f50d81fe,
    title = "Effect of ELMs on rotation and momentum confinement in H-mode discharges in JET",
    abstract = "The loss of plasma toroidal angular momentum and thermal energy by edge localized modes (ELMs) has been studied in JET. The analysis shows a consistently larger drop in momentum in comparison with the energy loss associated with the ELMs. This difference originates from the large reduction in angular frequency at the plasma edge, observed to penetrate into the plasma up to r/a ~ 0.65 during large type-I ELMs. As a result, the time averaged angular frequency is lowered near the top of the pedestal with increasing ELM frequency, resulting in a significant drop in thermal Mach number at the edge. An increase in profile peaking of ion temperature and angular frequency is observed. At the same time the plasma confinement is reduced while the ratio of confinement times (Rτ = τE/τ) increases noticeably with ELM frequency. This change could be explained by the relatively larger ELM induced losses for momentum in combination with the observed longer build-up time for the momentum density at the plasma edge.",
    author = "Versloot, {T. W.} and {de Vries}, {P. C.} and C. Giroud and M.-D. Hua and Beurskens, {M. N. A.} and M. Brix and T. Eich and {De La Luna}, E. and Tuomas Tala and V. Naulin and Zastrow, {K. D.} and {JET-EFDA collaborators}",
    year = "2010",
    doi = "10.1088/0741-3335/52/4/045014",
    language = "English",
    volume = "52",
    journal = "Plasma Physics and Controlled Fusion",
    issn = "0741-3335",
    publisher = "Institute of Physics IOP",
    number = "4",

    }

    Effect of ELMs on rotation and momentum confinement in H-mode discharges in JET. / JET-EFDA collaborators.

    In: Plasma Physics and Controlled Fusion, Vol. 52, No. 4, 045014, 2010.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Effect of ELMs on rotation and momentum confinement in H-mode discharges in JET

    AU - Versloot, T. W.

    AU - de Vries, P. C.

    AU - Giroud, C.

    AU - Hua, M.-D.

    AU - Beurskens, M. N. A.

    AU - Brix, M.

    AU - Eich, T.

    AU - De La Luna, E.

    AU - Tala, Tuomas

    AU - Naulin, V.

    AU - Zastrow, K. D.

    AU - JET-EFDA collaborators

    PY - 2010

    Y1 - 2010

    N2 - The loss of plasma toroidal angular momentum and thermal energy by edge localized modes (ELMs) has been studied in JET. The analysis shows a consistently larger drop in momentum in comparison with the energy loss associated with the ELMs. This difference originates from the large reduction in angular frequency at the plasma edge, observed to penetrate into the plasma up to r/a ~ 0.65 during large type-I ELMs. As a result, the time averaged angular frequency is lowered near the top of the pedestal with increasing ELM frequency, resulting in a significant drop in thermal Mach number at the edge. An increase in profile peaking of ion temperature and angular frequency is observed. At the same time the plasma confinement is reduced while the ratio of confinement times (Rτ = τE/τ) increases noticeably with ELM frequency. This change could be explained by the relatively larger ELM induced losses for momentum in combination with the observed longer build-up time for the momentum density at the plasma edge.

    AB - The loss of plasma toroidal angular momentum and thermal energy by edge localized modes (ELMs) has been studied in JET. The analysis shows a consistently larger drop in momentum in comparison with the energy loss associated with the ELMs. This difference originates from the large reduction in angular frequency at the plasma edge, observed to penetrate into the plasma up to r/a ~ 0.65 during large type-I ELMs. As a result, the time averaged angular frequency is lowered near the top of the pedestal with increasing ELM frequency, resulting in a significant drop in thermal Mach number at the edge. An increase in profile peaking of ion temperature and angular frequency is observed. At the same time the plasma confinement is reduced while the ratio of confinement times (Rτ = τE/τ) increases noticeably with ELM frequency. This change could be explained by the relatively larger ELM induced losses for momentum in combination with the observed longer build-up time for the momentum density at the plasma edge.

    U2 - 10.1088/0741-3335/52/4/045014

    DO - 10.1088/0741-3335/52/4/045014

    M3 - Article

    VL - 52

    JO - Plasma Physics and Controlled Fusion

    JF - Plasma Physics and Controlled Fusion

    SN - 0741-3335

    IS - 4

    M1 - 045014

    ER -