Renormalization-group analysis on the stability of large-scale electrostatic fluctuations of two-dimensional plasmas

Abstract

Stability of large-scale electrostatic fluctuations of forced two-dimensional plasma is studied by the use of the renormalization-group method. Large-scale flows have been rendered important in regulating turbulent plasma states and many recent works focus on their generation out of turbulence. This work is motivated by the recent result that the long-wavelength fluctuations can either grow or decay as a result of the interactions between the short-scale fluctuations depending anisotropically on the spectra of the small-scale turbulence. The Hasegawa-Mima model that is forced by an anisotropic Gaussian power-law noise is used and the renormalized viscosity up to the lowest-order coupling is computed. The result shows that the anisotropic portion of the viscosity may have opposite sign compared to the isotropic part, depending on the strength of the anisotropy. (C) 2004 American Institute of Physics.