[Table of Contents]

Plasma and Fusion Research

Volume 5, S2051 (2010)

Regular Articles

Collisionless Dynamical Friction and Relaxation in a Simple Drift Wave-Zonal Flow Turbulence
Yusuke KOSUGA and Patrick H. DIAMOND
Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla 92093, USA
(Received 20 December 2009 / Accepted 10 February 2010 / Published 10 December 2010)


We present a study of the role of zonal flows in relaxation and transport in a reduced model of collisionless ITG turbulence. A fundamentally new constituent in the relaxation dynamics is revealed, namely that ion and electron guiding center motion togather necessitate a radial flux of polarization charge, which in turn exerts a dynamical friction on phase space density evolution. This effect then enters the evolution of δf2 and the transport dynamics, as described by a Lenard-Balescu type equation. The underlying physics is similar to that which follows from conservation of potential vorticity, albeit now for a phase space fluid, and is not simple shearing or wave packet modulation. Consequences for zonal flow momentum balance are discussed.


drift wave, zonal flow, granulation, polarization charge, collisionless dynamical friction, momentum theorem

DOI: 10.1585/pfr.5.S2051


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This paper may be cited as follows:

Yusuke KOSUGA and Patrick H. DIAMOND, Plasma Fusion Res. 5, S2051 (2010).