Externally driven magnetic reconnection and a powerful magnetic energy converter

Abstract

Numerical simulation of two-dimensional compressible magnetic reconnection is carried out for more than a dozen cases with different anomalous resistivities and boundary conditions. After a quiescent stage of magnetic energy buildup, anomalous resistivity leads to an abrupt conversion of the stored magnetic energy into the plasma bulk motion and heat. Consequently, plasma jets as high as the local Alfvén speed are generated downstream of the magnetic separatrix. Slow shocks formed just downstream of the separatrix and fast mode expansion in the upstream region play a leading role in the formation of strong plasma jets. Anomalous resistivity is the primary cause of the abrupt onset of reconnection. Once reconnection preceeds, however, its ultimate fate no longer seems to be dependent on the resistivity, but is largely controlled by the boundary conditions.