Heating, current drive and confinement regimes with the JET ICRH and LHCD systems

J. Jacquinot, J.M. Adams, H. Altmann, A. Andersen, P. Andrew, M. Angelone, S.A. Arshad, W. Bailey, P. Ballantyne

    Research output: Contribution to journalConference articleResearchpeer-review

    Abstract

    During its 1990 operation, 2 large RF systems were available on JET. The Ion Cyclotron Resonance Heating (ICRH) system was equipped with new beryllium screens and with feedback matching systems. Specific impurities generated by ICRH were reduced to negligible levels even in the most stringent H-mode conditions. A maximum power of 22 MW was coupled to L-mode plasmas. High quality H-modes (tau-E greater-than-or-equal-to 2.5 tau-EG) were achieved using dipole phasing. A new high confinement mode was discovered. It combines the properties of the H-mode regime to the low central diffusivities obtained by pellet injection. A value of n(d) tau-E T(i) = 7.8 x 10(20) m-3 s keV was obtained in this mode with T(e) approximately T(i) approximately 11 keV. In the L-mode regime, a regime, a record (140 kW) D-He-3 fusion power was generated with 10 - 14 MW of ICRH at the He-3 cyclotron frequency.

    Experiments were performed with the prototype launcher of the Lower Hybrid Current Drive (LHCD) systems with coupled power up to 1.6 MW with current drive efficiencies up to < n(e) > R I(CD)/P = 0.4 x 10(20) m-2 A/W. Fast electrons are driven by LHCD to tail temperatures of 100 keV with a hollow radial profile. Paradoxically, LHCD induces central heating particularly in combination with ICRH. Finally we present the first observations of the synergistic acceleration of fast electrons by Transit Time Magnetic Pumping (TTMP) (from ICRH) and Electron Landau Damping (ELD) (from LHCD). The synergism generates TTMP current drive even without phasing the ICRH antennae.
    Original languageEnglish
    JournalPlasma Physics and Controlled Fusion
    Volume33
    Issue number13
    Pages (from-to)1657-1675
    ISSN0741-3335
    DOIs
    Publication statusPublished - 1991
    Event18th Eorupean Conference on Controlled Fusion and Plasma Physics - Berlin, Germany
    Duration: 3 Jun 19917 Jun 1991
    Conference number: 18

    Conference

    Conference18th Eorupean Conference on Controlled Fusion and Plasma Physics
    Number18
    CountryGermany
    CityBerlin
    Period03/06/199107/06/1991

    Keywords

    • ICRH
    • LHCD
    • H-MODE
    • L-MODE
    • HEATING
    • CONFINEMENT
    • FUSION YIELD
    • PEAKED DENSITY PROFILES
    • ANTENNA SCREEN
    • EDGE PHYSICS
    • SYNERGISTIC EFFECTS
    • CURRENT

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