Nonlinear Phase Mixing and Phase-Space Cascade of Entropy in Gyrokinetic Plasma Turbulence

Journal Article · Fri Jul 03 00:00:00 EDT 2009 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.103.015003· OSTI ID:21347025

Tatsuno, T; Dorland, W; Plunk, G G ^[1]; Schekochihin, A A ^[2]; Barnes, M ^[1]; Cowley, S C ^[3]; Howes, G G ^[4]

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1. Department of Physics, IREAP and CSCAMM, University of Maryland, College Park, Maryland 20742 (United States)
2. Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP (United Kingdom)
3. Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)
4. Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

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.

• OSTI ID: 21347025
• Journal Information: Physical Review Letters, Vol. 103, Issue 1; Other Information: DOI: 10.1103/PhysRevLett.103.015003; (c) 2009 The American Physical Society; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DISTRIBUTION FUNCTIONS
ENTROPY
FLUCTUATIONS
LARMOR RADIUS
NONLINEAR PROBLEMS
PHASE SPACE
PLASMA
TURBULENCE
TURBULENT HEATING
FUNCTIONS
HEATING
MATHEMATICAL SPACE
PHYSICAL PROPERTIES
PLASMA HEATING
SPACE
THERMODYNAMIC PROPERTIES
VARIATIONS