Experimental studies of the interaction between fast ions, Alfvén eigenmodes and fishbones, microturbulence, and zonal flows in the DIII-D tokamak

POSTER

Abstract

Cross-scale couplings between fast ions, Alfvén eigenmodes (AE), and microturbulence are theoretically predicted to impact both saturated AE and drift-wave amplitudes and the fast- and thermal-ion transport they cause. An experimental “thrust” to study these interactions in the DIII-D tokamak is underway. Three dedicated experiments are scheduled for Summer 2024. The first focuses on the effect of fast-ion dilution on microturbulence in plasmas without AE activity. The second seeks detection of AE-induced zonal flows using beam-emission spectroscopy (BES) and Doppler backscattering (DBS) diagnostics. In the third experiment, BES and DBS diagnostics will search for the theoretically predicted fishbone-induced zonal flow that was correlated with triggering of an internal transport barrier [1]. Analysis of existing data hints at the existence of zonal flows that are driven by either AEs or fast ions. Preliminary thrust highlights will be presented.



[1] G. Brochard et al., PRL 132 (2024) 075101.

Presenters

  • William Walter Heidbrink

    University of California, Irvine

Authors

  • William Walter Heidbrink

    University of California, Irvine

  • Xiaodi Du

    General Atomics

  • Deyong Liu

    General Atomics

  • Michael A Van Zeeland

    General Atomics, General Atomics - San Diego

  • Rongjie Hong

    UCLA

  • Lothar W Schmitz

    University of California Los Angeles, TAE Technologies, University of California, Los Angeles, University of California Los Angeles

  • George R McKee

    University of Wisconsin-Madison, University of Wisconsin, Madison

  • Guillaume Richard Brochard

    ITER organization