Turbulent Transport Reduction by Zonal Flows: Massively Parallel Simulations
Z. Lin,
T. S. Hahm,
W. W. Lee,
W. M. Tang,
R. B. White
Three-dimensional gyrokinetic simulations of microturbulence in
magnetically confined toroidal plasmas with massively parallel computers showed that, with linear flow damping, an asymptotic residual
flow develops in agreement with analytic calculations. Nonlinear global
simulations of instabilities driven by temperature gradients in the ion
component of the plasma support the view that turbulence-driven
fluctuating zonal flows can substantially reduce turbulent transport.
Finally, the outstanding differences in the flow dynamics observed in
global and local simulations are found to be due to profile variations.
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