Structure of the diffusion region in three dimensional magnetic reconnection

Abstract

Although magnetic reconnection has been successfully used to explain many different astrophysical phenomena, it has yet to demonstrate some key properties observed in smaller bursty plasma flows within the magnetotail. In this thesis, we present 3D Hall simulations demonstrating that under wide equilibrium current sheet conditions, magnetic reconnection will become transient and localized. In doing so, we show that magnetic reconnection is capable of producing the bursty bulk flows observed in the magnetotail. Toward this goal, we first introduce a new framework for analyzing 3D magnetic reconnection. Using this framework, we deconstructthe significant physical structures and processes comprising x-lines derivedfrom a thin equilibrium current sheets. After establishing this mapping of the 3D diffusion region, we move on to probe the more marginal cases of reconnection whichresult from very wide equilibrium current sheets. Finally, we incorporate all of this into a simple analytical model for 3D reconnection--reproducing many of the observed properties of both transient magnetic reconnection and long-lasting magnetic reconnection. By doing so, not only do we expand upon the known behaviors of magnetic reconnection, but we also present novel insight into the mechanisms behind these behaviors.