Role of Zonal Flow Predator-Prey Oscillations in Triggering the Transition to H-Mode Confinement

2012287 citationsJournal Articlegreen Open Access

Authors

L. Schmitz · University of California, Los Angeles

L. Zeng · University of California, Los Angeles

T. L. Rhodes · University of California, Los Angeles

J.C. Hillesheim · University of California, Los Angeles

E. J. Doyle · University of California, Los Angeles

R. J. Groebner · General Atomics (United States)

W. A. Peebles

Abstract

Direct evidence of zonal flow (ZF) predator-prey oscillations and the synergistic roles of ZF- and equilibrium E×B flow shear in triggering the low- to high-confinement (L- to H-mode) transition in the DIII-D tokamak is presented. Periodic turbulence suppression is first observed in a narrow layer at and just inside the separatrix when the shearing rate transiently exceeds the turbulence decorrelation rate. The final transition to H mode with sustained turbulence and transport reduction is controlled by equilibrium E×B shear due to the increasing ion pressure gradient.

Topics & Keywords

Magnetic confinement fusion research Fusion materials and technologies Laser-Plasma Interactions and Diagnostics

UN Sustainable Development Goals

Life below water

Publication Details

Published in: Physical Review Letters

Volume 108, Issue 15, pp. 155002-155002

DOI: 10.1103/physrevlett.108.155002

Field-Weighted Citation Impact: 45.92