Threshold Heat-Flux Reduction by Near-Resonant Energy Transfer

P. W. Terry, P.-Y. Li, M. J. Pueschel, and G. G. Whelan

Phys. Rev. Lett. 126, 025004 – Published 15 January 2021

Abstract

Near-resonant energy transfer to large-scale stable modes is shown to reduce transport above the linear critical gradient, contributing to the onset of transport at higher gradients. This is demonstrated for a threshold fluid theory of ion temperature gradient turbulence based on zonal-flow-catalyzed transfer. The heat flux is suppressed above the critical gradient by resonance in the triplet correlation time, a condition enforced by the wave numbers of the interaction of the unstable mode, zonal flow, and stable mode.

Received 6 October 2020
Revised 22 December 2020
Accepted 4 January 2021

DOI:https://doi.org/10.1103/PhysRevLett.126.025004

Physics Subject Headings (PhySH)

Drift waves Magnetic confinement fusion Nonlinear phenomena in plasmas Plasma turbulence

Plasma Physics

Authors & Affiliations

P. W. Terry¹, P.-Y. Li¹, M. J. Pueschel^2,3,4, and G. G. Whelan¹

¹University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
²Dutch Institute for Fundamental Energy Research, 5612 AJ Eindhoven, Netherlands
³Eindhoven University of Technology, 5600 MB Eindhoven, Netherlands
⁴Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712, USA