[Table of Contents]

Plasma and Fusion Research

Volume 5, 019 (2010)

Rapid Communications

Global Profile Relaxation and Entropy Dynamics in Turbulent Transport
Kenji IMADERA, Yasuaki KISHIMOTO and Jiquan LI
Department of Fundamental Energy Science, Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan
(Received 3 March 2010 / Accepted 9 April 2010 / Published 14 June 2010)


A hierarchical entropy balance equation retaining the dynamics in the radial direction is introduced to study non-local turbulent transport and the associated global profile relaxation. It consists of first- and second-order equations that describe the entropy dynamics related to thermodynamics/fluid quantity and the corresponding micro-scale phase space fluctuations, respectively. Specifically, the second-order equation describes not only a local entropy production related to heat and density flux (i.e., zonal flow), but also the spatial convection of perturbed entropy. We investigated the entropy dynamics in ion-temperature-gradient driven turbulence based on a global gyrokinetic Vlasov simulation in slab geometry. Entropy convection plays an important role in the relaxation dynamics dominated by the avalanche process. A self-organized relaxed state is established, in which short-wavelength temperature corrugation, i.e., zonal pressure, is regulated by zonal flow shear.


phase space entropy, global relaxation, turbulent spreading, gyrokinetic simulation

DOI: 10.1585/pfr.5.019


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This paper may be cited as follows:

Kenji IMADERA, Yasuaki KISHIMOTO and Jiquan LI, Plasma Fusion Res. 5, 019 (2010).