Density profile peaking on DIII-D and JET – fuelling versus transport

Antti Salmi, Tuomas Tala, S. Mordijck, Hans Nordman, Jerry W. Hughes

    Research output: Contribution to conferenceConference AbstractScientific

    Abstract

    Dimensionless collisionality (ν*) scans with fixed density in H-mode plasmas on DIII-D and JET together with modelling have shown that the NBI fuelling plays a more important role in density peaking than found in earlier multi-machine datasets where the increased peaking at low collisionality has been primarily ascribed to turbulent effects. Perturbative gas puff modulations are performed to disentangle the fuelling and the transport effects. On DIII-D, we find that, at the lowest ν*, the pinch is directed outward and the diffusion coefficients are larger compared to higher ν* cases. With increasing ν*, the pinch becomes inward outside the mid-radius, while remaining outward inside the mid-radius. At the same time, a strong increase in ion-scale density fluctuations with reduced ν* is observed with BES and predicted with TGLF. On JET, perturbative transport analysis, predictive integrated modelling with JINTRAC+TGLF and non-linear and linear GENE runs all show that NBI fuelling provides an important contribution to density peaking. These results indicate that the density profiles on ITER, where NBI fuelling is very small, may be less peaked than previously thought.
    Original languageEnglish
    Publication statusPublished - 2018
    MoE publication typeNot Eligible
    Event60th Annual Meeting of the APS Division of Plasma Physics - Portland, Portland, United States
    Duration: 5 Nov 20189 Nov 2018
    Conference number: 60
    https://www.aps.org/units/dpp/meetings/annual/

    Conference

    Conference60th Annual Meeting of the APS Division of Plasma Physics
    CountryUnited States
    CityPortland
    Period5/11/189/11/18
    Internet address

    Fingerprint Dive into the research topics of 'Density profile peaking on DIII-D and JET – fuelling versus transport'. Together they form a unique fingerprint.

    Cite this