HYBRID SIMULATIONS OF MAGNETOTAIL RECONNECTION: TURBULENCE IN THE POST PLASMOID PLAMA SHEET

摘要

Large-scale hybrid simulations of magnetotail recon-nection have been performed. The in-plane Hall currents during reconnection lead to large cross-tail magnetic fields with a quadrupolar structure. For a considerable distance from the neutral line the reconnection layer is characterized by highly anisotropic ion distribution functions. At larger distances the current layer becomes unstable, and the ion distribution is hot and isotropic. The instability is explained in terms of the combined action of velocity shear and anisotropic ion distribution functions. The turbulence spectrum in the post plamoid plasma sheet is surprisingly close to what has been observed in the distant tail.