Transport reduction by rotation shear in tokamak-edge turbulence.
Effects of externally imposed and self-generated poloidal flows on turbulent transport in the edge region of a tokamak are investigated using 3D nonlinear global simulations of resistive pressure-gradient-driven turbulence. Transport reduction is found to be due to synergetic changes in the fluctuation amplitude and in the dephasing of the fluctuations. A scaling of the fluctuation level and turbulent diffusivity with E x B flow shear strength is deduced from these simulations. These scalings agree with recent experimental observations on edge biasing as well as with analytical models.
Figarella
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CF
Equipe Dynamique des Systèmes Complexes, LPIIM, UMR 6633 CNRS-Université de Provence, Centre St. Jérôme, Case 321, 13397 Marseille Cedex 20, France.
Benkadda
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S
Beyer
P
P
Garbet
X
X
Voitsekhovitch
I
I