Critically balanced ion temperature gradient turbulence in fusion plasmas

TL;DR

This paper derives scaling laws for ion temperature gradient turbulence in magnetized plasmas, confirming their accuracy through simulations and supporting the critical balance conjecture that turbulence is inherently three-dimensional.

Contribution

It introduces new scaling laws for ion temperature gradient turbulence and provides evidence supporting the critical balance conjecture in magnetized plasmas.

Findings

Scaling laws agree with numerical simulations.

Turbulence exhibits critical balance between parallel and perpendicular scales.

Plasma turbulence is inherently three-dimensional.

Abstract

Scaling laws for ion temperature gradient driven turbulence in magnetized toroidal plasmas are derived and compared with direct numerical simulations. Predicted dependences of turbulence fluctuation amplitudes, spatial scales, and resulting heat fluxes on temperature gradient and magnetic field line pitch are found to agree with numerical results in both the driving and inertial ranges. Evidence is provided to support the critical balance conjecture that parallel streaming and nonlinear perpendicular decorrelation times are comparable at all spatial scales, leading to a scaling relationship between parallel and perpendicular spatial scales. This indicates that even strongly magnetized plasma turbulence is intrinsically three-dimensional.