Driven Reconnection Controlled By Particle Dynamics In A Collisionless Open System

Long time scale evolution of collisionless driven reconnection in an open system is investigated by using newly developed electromagnetic particle simulation codes. It is found that there are two evolving regimes in the temporal behavior of collisionless reconnection, dependently on the spatial size of plasma inflow through the upstream boundary (window size), i.e., a steady regime and an intermittent regime. The system evolves toward a steady regime for a narrow input window, in which collisionless reconnection is controlled by ion dynamics. On the other hand, an intermittent behavior appears due to the frequent formation of magnetic islands for a wide input window, in which an electron dynamics plays an important role