Plasma Physics

We study magnetic reconnection X-line spreading in a Harris current sheet using three-dimensional particle-in-cell (PIC) simulations. We found that without drift-kink instability, the X-line spreads in ambient ion-drifting speed in the ion-drifting direction while the X-line barely spreads in the electron-drifting direction. With drift-kink instability, the X-line stops spreading after the instability grows to large amplitudes. The interaction between X-line spreading and drift-kink instability could be important in the context of Earth’s magnetotail.

We study magnetic reconnection using 2D resistivity magnetohydrodynamics simulations and found that fast reconnection can be achieved by a resistivity gradient in the outflow direction. We also tested how the reconnection rate increases with increasing resistivity and found that current density decreases significantly at the X-line.