Magnetic reconnection in a charged, electron-dominant current sheet

Abstract

Magnetic reconnection occurs in current sheets in various plasma environments, and the reconnection process is controlled by the current sheet characteristics. Most theoretical and simulation studies of magnetic reconnection are based on the neutral current sheet model in which the current is primarily carried by ions. Current sheets in natural plasmas (e.g., in Earth's magnetotail), however, are usually charged with nonzero electric field, and usually the current therein is primarily carried by electrons. Here using particle-in-cell simulations, we study magnetic reconnection in a charged, electron-dominant current sheet and show that reconnection in this current sheet is weaker, has a larger diffusion region, and occurs more easily than reconnection in the neutral, ion-dominant current sheet. Two other current sheet characteristics, the background density and background temperature, also affect the reconnection process significantly.