Towards steady state tokamak operation with double transport barriers

Tuomas Tala, JET Contributors, F. Söldner (Corresponding Author)

    Research output: Contribution to journalArticle in a proceedings journalScientificpeer-review

    14 Citations (Scopus)


    Core confinement and the overall performance of the tokamak have been considerably enhanced with the combination of two improved confinement regimes. Internal transport barriers characteristic of the optimized shear regime and an edge transport barrier of the high confinement H mode regime have been superposed in the double barrier (DB) mode. In DT discharges the DB mode has resulted in a fusion gain Q a factor of 2 higher than in conventional sawtoothing steady state ELMy H mode plasmas. The DB mode has been routinely established in the new Gas Box divertor configuration on JET. Off-axis lower hybrid current drive and edge radiation cooling through impurity seeding have been used for current and pressure profile control. This has made it possible to increase the performance up to βN = 2.4 and H89 = 2.7 and to extend flat-top phases up to a duration of three energy confinement times, approaching steady state conditions. Modelling studies of DB mode DT operation on JET predict a fusion power in the range 20-30 MW. In ITER transport code modelling, steady state operation with a fusion power output of 1.3 GW is obtained for advanced tokamak scenarios in the DB mode.
    Original languageEnglish
    JournalNuclear Fusion
    Issue number11Y
    Publication statusPublished - 1999
    MoE publication typeA4 Article in a conference publication
    Event17th IAEA Fusion Energy Conference - Yokohama, Japan
    Duration: 19 Oct 199824 Oct 1998


    Dive into the research topics of 'Towards steady state tokamak operation with double transport barriers'. Together they form a unique fingerprint.

    Cite this