Fast Magnetic Reconnection Processes

Abstract

It is found through theory and magnetohydrodynamic particle simulation that fast magnetic-field-line reconnection may consist of more than one stage. After the Sweet-Parker phase is established for an Alvén time, a faster "second phase" of reconnection takes over if the plasma is compressible: The reconnected flux varies as $\psi ={\psi }_0{t}^{\frac{{\rho }_i}{{\rho }_e}}$, where ${\rho }_e$ and ${\rho }_i$ refer to the plasma densities outside and inside of the current channel.