Effect of resonance magnetic perturbation on edge-core turbulence spreading in a tokamak plasma

TL;DR

This study investigates how resonance magnetic perturbations influence turbulence spreading in tokamak plasmas, revealing that RMP-induced shear flows can suppress core turbulence by disrupting vortex structures.

Contribution

It introduces an electromagnetic Landau-fluid model to simulate RMP effects on turbulence spreading, highlighting the role of shear flows in turbulence suppression.

Findings

RMP excites long wavelength fluctuations at the resonance surface.

Shear flows at magnetic islands break vortex structures.

Inward turbulence flux is reduced, lowering core turbulence saturation.

Abstract

Turbulence spreading from edge to core region with resonance magnetic perturbation (RMP) is investigated using an electromagnetic Landau-fluid model in toroidal geometry. When RMP field with appropriate amplitude are employed in the simulation, long wavelength fluctuations around the resonance surface are excited due to the forced magnetic reconnection. Strong shear flow at the magnetic island separatrix are observed, and break the radial elongated vortex structures of the turbulent fluctuation. The inward flux could be blocked by this shear flow and the saturation level in the core region declines.