Clumps in the Resistive-Drift-Wave turbulence

TL;DR

This paper uses numerical simulations of the Hasegawa-Wakatani equation to show that resistive-drift-wave turbulence is vortex-dominated, with vortices forming dipoles that propagate ballistically, influencing plasma transport and stability.

Contribution

It reveals the vortex-dominated nature of RDW turbulence and the ballistic propagation of vortex dipoles, highlighting non-local plasma transport mechanisms.

Findings

Vortices dominate RDW turbulence at low adiabaticity.

Vortex dipoles propagate ballistically over large distances.

Clumps can trigger other plasma instabilities.

Abstract

The results of numerical simulations of the Hasegawa-Wakatani equation demonstrate that, similarly to decaying turbulence in 2D fluids, at a small electron adiabaticity parameter, the resistive-drift-wave (RDW) turbulence is dominated by the vortices. Occasionally, vortices with different signs become coupled and propagate ballistically as a dipole over a large distance, entraining plasma density. Such ballistic motion of the vortex-density clumps in radial direction provides a non-local feature of plasma transport associated with the RDW turbulence. Large magnitude of plasma parameters perturbations associated with clumps can initiate other plasma instabilities and nonlinear phenomena.