Strategies for reaching high density and opacity conditions leveraging the Shape and Volume Rise divertor on DIII-D

POSTER

Abstract

A new divertor geometry enabling high shaping on DIII-D has been leveraged to achieve among the highest pedestal pressures observed to date on the device, yielding: 1) plasmas with Edge Localized Modes (ELMs) at high absolute parameters (βpedN > 1.3, Teped > 2keV, Tiped >3keV); 2) highly decoupled peeling and ballooning instabilities through high shaping at δ=0.96 and κ=2.04; 3) Quiescent H-mode plasmas with ne,0 = 1.2x1020m-3 and nesep six times greater than typical QH-modes, separately attaining Tiped >5.5keV; and 4) resonant magnetic perturbation studies indicating enhanced resonance with elevated βN values, particularly for high triangularity plasmas close to magnetic balance; and 5) ELM suppression at dRsep values as low as 0.3cm. A significant experimental thrust leverages this new divertor geometry to access reactor relevant conditions of simultaneous high pressure, density, and opacity with a pedestal limited by peeling instabilities. Pushing to this new regime is an important step towards closing the Integrated Tokamak Exhaust and Performance gap required to extrapolate present regimes to future devices. This poster overviews results of team experiments with an emphasis on the impact of shaping and profile structure on pedestal stability, specifically for the ELMy scenario.

*This work was supported in part by the US Department of Energy under DE-FC02-04ER54698, DE-SC0014264, DE-AC05-00OR22725, DE-AC02-09CH11466, DE-SC0019302, DE-AC52-07NA27344, DE-SC0022270, and DE-FG02-04ER54761.

Presenters

  • Theresa M Wilks

    • Massachusetts Institute of Technology

Authors

  • Theresa M Wilks

    • Massachusetts Institute of Technology

  • Thomas H Osborne

    • General Atomics

  • Matthias Knolker

    • General Atomics

  • Qiming Hu

    • Princeton University
    • Princeton Plasma Physics Laboratory (PPPL)

  • KyuBeen Kwon

    • Oak Ridge Associated Universities

  • Robert S Wilcox

    • Oak Ridge National Laboratory

  • Philip B Snyder

    • Oak Ridge National Laboratory
    • Commonwealth Fusion Systems

  • Darin R Ernst

    • Massachusetts Institute of Technology

  • Xinxing Ma

    • General Atomics

  • Alan Hyatt

    • General Atomics

  • Julio Jose Balbin Arias

    • William & Mary

  • Raul Gerru Miguelanez

    • Massachusetts Institute of Technology

  • Sophie Gorno

    • Oak Ridge National Laboratory

  • Christopher T Holcomb

    • Lawrence Livermore National Laboratory

  • Andreas Michael Holm

    • Lawrence Livermore National Laboratory

  • Jerry W Hughes

    • MIT Plasma Science and Fusion Center
    • Massachusetts Institute of Technology

  • Amanda E Hubbard

    • Massachusetts Institute of Technology
    • MIT Plasma Science and Fusion Center

  • Andrew O Nelson

    • Columbia University

  • Filippo Scotti

    • Lawrence Livermore National Laboratory

  • Morgan W Shafer

    • Oak Ridge National Laboratory

  • Daisuke Shiraki

    • Oak Ridge National Laboratory

  • Francesca Turco

    • Columbia University

  • James J Yang

    • Princeton Plasma Physics Laboratory (PPPL)

  • Huiqian Wang

    • General Atomics