Gyrokinetic turbulence: A nonlinear route to dissipation through phase space

A. A. Schekochihin, S. C. Cowley, W. Dorland, G. W. Hammett, G. G. Howes, G. G. Plunk, E. Quataert, T. Tatsuno

Research output: Contribution to journalArticlepeer-review

97 Scopus citations

Abstract

This paper describes a conceptual framework for understanding kinetic plasma turbulence as a generalized form of energy cascade in phase space. It is emphasized that conversion of turbulent energy into thermodynamic heat is only achievable in the presence of some (however small) degree of collisionality. The smallness of the collision rate is compensated for by the emergence of a small-scale structure in the velocity space. For gyrokinetic turbulence, a nonlinear perpendicular phase-mixing mechanism is identified and described as a turbulent cascade of entropy fluctuations simultaneously occurring at spatial scales smaller than the ion gyroscale and in velocity space. Scaling relations for the resulting fluctuation spectra are derived. An estimate for the collisional cutoff is provided. The importance of adequately modelling and resolving collisions in gyrokinetic simulations is briefly discussed, as well as the relevance of these results to understanding the dissipation-range turbulence in the solar wind and the electrostatic microturbulence in fusion plasmas.

Original languageEnglish (US)
Article number124024
JournalPlasma Physics and Controlled Fusion
Volume50
Issue number12
DOIs
StatePublished - 2008
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Nuclear Energy and Engineering
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Gyrokinetic turbulence: A nonlinear route to dissipation through phase space'. Together they form a unique fingerprint.

Cite this