Three Dimensional Electron-Only Reconnection

Recent MMS observations in the downstream of the quasi-parallel shock have shed some light into small scale ''electron-only'' magnetic reconnection embedded inside turbulence. In such magnetic reconnection events, large guide field and beta ~ 1, the parallel electric field close to the x-line is measured to be about ~8mV/ m , much larger than measured in previously observed magnetic reconnection events. In 2.5D simulations, it has been shown that the reconnection rate for fully ion-coupled magnetic reconnection is of the order 0.1c_A , far below recent spacecraft observations of the electron-only reconnection. We perform force-free three dimensional particle-in-cell simulation of high beta plasma to find that magnetic reconnection in 3D is inherently faster than in traditional 2.5D PIC simulation with enhanced parallel electric field, thereby giving us some context and understanding of magnetic reconnection found in the turbulent magnetosheath.