Non-Ballooning Electron Temperature Gradient Turbulence in the Tokamak Pedestal

ORAL

Abstract

Tokamak pedestal electron temperature gradient (ETG) turbulence has a complex three-dimensional structure that is highly inhomogeneous in the poloidal direction, particularly at ion scales. Nonlinear multiscale gyrokinetic simulations of Joint European Torus pedestals reveal that ETG pedestal turbulence has maximum fluctuation amplitudes and transport near the top and bottom of a flux surface, rather than the outboard midplane. Its parallel distribution is determined by the magnetic field geometry and steep equilibrium gradients, with magnetic drift and finite Larmor radius effects being particularly important. Nonlinear simulations must run sufficiently long for the slower ion-scale ETG turbulence to saturate and interact with electron-scale ETG turbulence.

*FIP and MB are supported in part by the RCUK Energy-Programme (grant number EP/EPI501045). FIP, MRH, MB, DS, and DD are supported in part by the TDoTP project funded by EPSRC (grant number EP/R034737/1). This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 and 2019-2020 under Grant Agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. This work has been carried out within the framework of the Contract for the Operation of the JET Facilities and has received funding from the European Union's Horizon 2020 research and innovation programme. This work was performed using the Cambridge Service for Data Driven Discovery (CSD3), operated by the University of Cambridge Research Computing on behalf of the STFC DiRAC HPC Facility. The DiRAC component of CSD3 was funded by BEIS capital funding via STFC capital grants S

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Publication: Planned: Three-Dimensional Electron Temperature Gradient Turbulence in the Tokamak Pedestal

Presenters

  • Jason F Parisi

    • EURATOM/CCFE

Authors

  • Jason F Parisi

    • EURATOM/CCFE

  • Felix I Parra

    • University of Oxford
    • Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford, OX1 3PU, UK
    • Oxford University

  • Colin M Roach

    • CCFE

  • Michael R Hardman

    • University of Oxford

  • Michael Barnes

    • University of Oxford
    • Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford, OX1 3PU, UK
    • Oxford University

  • William D Dorland

    • University of Maryland, College Park
    • Princeton Plasma Physics Laboratory
    • University of Maryland Department of Physics
    • UMD

  • Denis A St-Onge

    • University of Oxford

  • Justin Ball

    • EPFL

  • David R Hatch

    • University of Texas at Austin
    • Institute for Fusion Studies, University of Texas at Austin

  • David Dickinson

    • York Plasma Institute, Department of Physics, University of York, Heslington, York, YO10 5DD, UK
    • University of York
    • York Plasma Institute

  • Samuli Saarelma

    • General Atomics
    • CCFE

  • Benjamin Chapman

    • CCFE

  • Carine Giroud

    • CCFE

  • Jon C Hillesheim

    • CCFE
    • Culham Science Centre

  • Noboyuki Aiba

    • National Institutes for Quantum and Radiological Science and Technology