Fully Kinetic Simulation of 3D Kinetic Alfven Turbulence [CL]


We present results from a fully kinetic, three-dimensional plasma turbulence simulation, resembling the typical plasma conditions found at kinetic scales of the solar wind. The spectral properties of the turbulence in the sub-ion range are consistent with theoretical expectations for kinetic Alfv\’ en waves. Furthermore, we calculate the scale-dependent anisotropy, defined by the relation $k_{\parallel}(k_{\perp})$, where $k_{\parallel}$ is a characteristic wavenumber along the local mean magnetic field at perpendicular scale $l_{\perp}\sim 1/k_{\perp}$. Over a limited range of sub-ion scales, the obtained scaling is close to $k_{\parallel}\propto k_{\perp}^{1/3}$, consistent with the standard analytical prediction for a critically balanced kinetic Alfv\’ en cascade. Our results compare favourably against a number of in-situ solar wind observations and demonstrate—from first principles—the feasibility of plasma turbulence models based on a critically balanced cascade of kinetic Alfv\’ en waves.

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D. Groselj, A. Mallet, N. Loureiro, et. al.
Wed, 11 Oct 17

Comments: submitted for publication