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Paper: |
Three-dimensional Hall Magnetohydrodynamics Turbulence |
Volume: |
459, 6th International Conference of Numerical Modeling of Space Plasma Flows (ASTRONUM 2011) |
Page: |
28 |
Authors: |
Meyrand, R.; Galtier, S. |
Abstract: |
Direct numerical simulations of three-dimensional incompressible Hall magnetohydrodynamics are performed in a
triple periodic box at moderate resolution. To investigate the transition from a large scale MHD turbulence regime
to a small scale dispersive one we introduce a variable ion inertial length scale dI(t) which characterizes the
strength of the Hall effect. By slowly increasing dI we are able to move our window of resolution from the pure
MHD scales to the full Hall MHD one. We estimate the value of dI from which the Hall MHD regime appears.
The present analysis is relevant in the context of solar wind turbulence where the power law spectrum for the
magnetic field fluctuations steepens significantly at frequencies higher than a fraction of Hertz. This change of
turbulence regime raises fundamental questions in plasma physics about the transition from a fluid model to a
pure kinetic one. |
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