Hybrid (Kinetic Ion/Fluid Electron) Simulations of Reconnection Including Electron Pressure Anisotropy

Abstract:

Fully kinetic simulations have shown that the structure of the thin current
sheets that form during collisionless reconnection can fall into a variety
of regimes depending on the electron pressure anisotropy [1]. Furthermore,
recent two-fluid simulations with anisotropic electron equations of state
appropriate for reconnection confirm that the electron pressure anisotropy
may drive highly elongated current sheets in the reconnection exhaust [2].
While fully kinetic simulations are useful to model small regions of the
Earth's magnetosphere, they are still far too expensive for global modeling.
Thus, we have implemented the electron equations of state in the hybrid
(kinetic ions and fluid electrons) code H3D [3], and initial 2D hybrid
simulations of reconnection agree well with fully kinetic simulations. The
updated hybrid code is a first step towards including electron anisotropy
and full ion kinetics in global simulations of Earth's magnetosphere and
laboratory experiments.

[1] Le et al., Phys. Rev. Lett. 110, 135004 (2013)

[2] Ohia et al., Phys. Rev. Lett. 109, 115004 (2012)

[3] Karimabadi et al., Phys. Plasmas 21, 062308 (2014)