Nonlinear phase mixing and phase-space cascade of entropy in gyrokinetic plasma turbulence.

Journal article

Electrostatic turbulence in weakly collisional, magnetized plasma can be interpreted as a cascade of entropy in phase space, which is proposed as a universal mechanism for dissipation of energy in magnetized plasma turbulence. When the nonlinear decorrelation time at the scale of the thermal Larmor radius is shorter than the collision time, a broad spectrum of fluctuations at sub-Larmor scales is numerically found in velocity and position space, with theoretically predicted scalings. The results are important because they identify what is probably a universal Kolmogorov-like regime for kinetic turbulence; and because any physical process that produces fluctuations of the gyrophase-independent part of the distribution function may, via the entropy cascade, result in turbulent heating at a rate that increases with the fluctuation amplitude, but is independent of the collision frequency.

Authors: Tatsuno, T; Dorland, W; Schekochihin, A; Plunk, G; Barnes, M

• Publication status: Published
• Journal: Physical Review Letters
• Volume: 103
• Issue: 1
• Pages: 015003
• Publication date: 2009-07-01
• DOI: 10.1103/physrevlett.103.015003
• EISSN: 1079-7114
• ISSN: 0031-9007
• Language: English
• Keywords: physics.comp-ph; physics.flu-dyn; physics.plasm-ph