Turbulent Equipartition Theory of Toroidal Momentum Pinch
Authors: T.S. Hahm, P.H. Diamond, O.D. Gurcan, and G. Rewaldt
The mode-independet part of magnetic curvature driven turbulent convective (TuroCo) pinch of the angular momentum density [Hahm et al., Phys. Plasmas 14,072302 (2007)] which was originally derived from the gyrokinetic equation, can be interpreted in terms of the turbulent equipartition (TEP) theory. It is shown that the previous results can be obtained from the local conservation of "magnetically weighted angular momentum density," nmi U|| R⁄B2, and its homogenization due to turbulent flows. It is also demonstrated that the magnetic curvature modification of the parallel acceleration in the nonlinear gyrokinetic equation in the laboratory frame, which was shown to be responsible for the TEP part of the TurCo pinch of angular momentum density in the previous work, is closely related to the Coriolis drift coupling to the perturbed electric field. In addition, the origin of the diffusive flux in the rotating frame is highlighted. Finally, it is illustratd that there should be a difference in scalings between the momentum pinch originated from inherently toroidal effects and that coming from other mechanisms which exist in a simpler geometry.
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Accepted for publication in Physics of Plasmas (May 2008)
Presented at: Forty-Ninth APS Division of Plasma Physics Meeting, 12–16 November 2007, Orlando, Florida USA
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Download PPPL-4285 (pdf 421 Kb)
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