Current sheets and pressure anisotropy in the reconnection exhaust

Articles you may be interested in A review of pressure anisotropy caused by electron trapping in collisionless plasma, and its implications for magnetic reconnection The effects of strong temperature anisotropy on the kinetic structure of collisionless slow shocks and reconnection exhausts. A particle-in-cell simulation shows that the exhaust during anti-parallel reconnection in the collisionless regime contains a current sheet extending 100 inertial lengths from the X line. The current sheet is supported by electron pressure anisotropy near the X line and ion anisotropy farther downstream. Field-aligned electron currents flowing outside the magnetic separatrices feed the exhaust current sheet and generate the out-of-plane, or Hall, magnetic field. Existing models based on different mechanisms for each particle species provide good estimates for the levels of pressure anisotropy. The ion anisotropy, which is strong enough to reach the firehose instability threshold, is also important for overall force balance. It reduces the outflow speed of the plasma.