Investigating electromagnetic effects on transport and turbulence in DIII-D QH-modes

POSTER

Abstract

Previous experiments and gyrokinetic simulations in the core ($\rho =$0.3) of QH-modes have found that the coupling of electrostatic turbulence to magnetic fluctuations ($\delta $B) at finite beta is very stabilizing to ITG/TEM turbulence [Guttenfelder, APS-DPP (2015); Ernst, Phys. Plasmas (2016)]. As expected from theory, the electromagnetic (EM) effects are significant as the profile is locally within \textasciitilde 90{\%} of the kinetic ballooning mode (KBM) threshold. Additional gyrokinetic and TGLF simulations have been run in advance of a planned QH-mode experiment aiming to directly measure core $\delta $B using cross polarization scattering (CPS). These ``predict first'' simulations will be shown to highlight the expected strength of EM effects, the scaling of the predicted amplitude of $\delta $B, and the proximity of profiles to the KBM threshold.

*This work supported in part by the U.S. Department of Energy under DE-AC02-09CH11466 and DE-FC02-04ER54698.

Authors

  • Walter Guttenfelder

    • Princeton Plasma Physics Lab
    • Princeton Plasma Physics Laboratory
    • PPPL
  • B.A. Grierson

    • PPPL
  • T.L. Rhodes

    • UCLA
  • K.H. Burrell

    • GA
  • G.M. Staebler

    • GA
  • D.R. Ernst

    • MIT