Details

Autor(en) / Beteiligte

• Tatsuno, T
• Dorland, W
• Schekochihin, A A
• Plunk, G G
• Barnes, M
• Cowley, S C
• Howes, G G

Titel

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

Ist Teil von

• Physical review letters, 2009-07, Vol.103 (1), p.015003-015003, Article 015003

Ort / Verlag

United States

Erscheinungsjahr

2009

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• 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.