Dynamics of zonal shear collapse with hydrodynamic electrons
| Autor: | Patrick Diamond, R. J. Hajjar, Mikhail Malkov |
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| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Physics of Plasmas. 25:062306 |
| ISSN: | 1089-7674 1070-664X |
| DOI: | 10.1063/1.5030345 |
| Popis: | This paper presents a theory for the collapse of the edge zonal shear layer, as observed at the density limit at low β. This paper investigates the scaling of the transport and mean profiles with the adiabaticity parameter α, with special emphasizes on fluxes relevant to zonal flow (ZF) generation. We show that the adiabaticity parameter characterizes the strength of production of zonal flows and so determines the state of turbulence. A 1D reduced model that self-consistently describes the spatiotemporal evolution of the mean density n¯, the azimuthal flow v¯y, and the turbulent potential enstrophy e=⟨(n−∇2ϕ)2/2⟩—related to fluctuation intensity—is presented. Quasi-linear analysis determines how the particle flux Γn and vorticity flux Π=−χy∇2vy+Πres scale with α, in both hydrodynamic and adiabatic regimes. As the plasma response passes from adiabatic (α > 1) to hydrodynamic (α 1) to hydrodynamic (α |
| Databáze: | OpenAIRE |
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