JET: Progress in performance and understanding

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

    Research output: Contribution to journalJournal articleResearch

    Abstract

    In 1990 JET operated with a number of technical improvements which led to advances in performance and permitted the carrying out of experiments specifically aimed at improving physics understanding of selected topics relevant to the "NEXT STEP". The new facilities include beryllium antenna screens, a prototype lower hybrid current drive system, and modification of the NI system to enable the injection of He-3 and He-4. Continued investigation of the hot-ion H-mode produced a value of n(D)(0)tau-E(T)(i)(0) = 9 x 10(20)m-3s keV, which is near conditions required for Q(DT) = 1, while a new peaked density profile H-mode was developed with only slightly lower performance. Progress towards steady state operation has been made by achieving ELMy H-modes under certain operating conditions, while maintaining good tau-E values. Experimental simulation of He ash transport indicates effective removal of alpha-particles from the plasma core for both L and H mode plasmas. Detailed analyses of particle and energy transport have helped establish a firmer link between particle and energy transport, and have suggested a connection between reduced energy transport and reversed shear. Numerical and analytic studies of divertor physics carried out for the pumped divertor phase of JET have helped clarify the key parameters governing impurity retention, and an intensive model validation effort has begun. Experimental simulation of alpha-particle effects with beta-fast up to 8% have shown that the slowing down processes are classical, and have given no evidence of deleterious collective effects.
    Original languageEnglish
    JournalPlasma Physics and Controlled Fusion
    Volume33
    Issue number13
    Pages (from-to)1453-1477
    ISSN0741-3335
    DOIs
    Publication statusPublished - 1991
    Event18th European Conference on Controlled Fusion and Plasma Physics - Berlin, Germany
    Duration: 3 Jun 19917 Jun 1991

    Conference

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

    Keywords

    • TOKAMAK
    • JET
    • Fusion Reactor
    • Particle transport
    • Energy transport
    • H-ModePhysics
    • Divertor Physics

    Cite this

    Keilhacker, M., Adams, J. M., Altmann, H., Andersen, A., Andrew, P., Angelone, M., Arshad, S. A., Bailey, W., & Ballantyne, P. (1991). JET: Progress in performance and understanding. Plasma Physics and Controlled Fusion, 33(13), 1453-1477. https://doi.org/10.1088/0741-3335/33/13/002