Anomalous Resistivity and Particle Kinetic Effects in Collisionless Driven 
Reconnection in Open Systems

R. Horiuchi (National Institute for Fusion Science)

Roles of plasma instabilities and particle kinetic effects in collisionless reconnection are 
investigated by means of two-dimensional and three-dimensional full particle simulations based 
on an open boundary model. Simulation runs with mass ratios from 25 to 800 has revealed that 
two-scale structure is formed in the current density profile and electron meandering effect in the 
central electron current sheet plays an important role in the generation of reconnection electric 
field in two-dimensional steady reconnection, although the evolution of whole reconnection 
system is controlled mainly by an external condition. Explosive energy release is observed in an 
intermittent reconnection, in which magnetic islands generated in the current sheet evolve 
propagating in the downstream. In three-dimensional case plasma instabilities are excited and 
affect the dynamical behavior of collisionless reconnection. In the presence of an external driving 
source the lower hybrid drift (LHD) waves excited in the periphery propagate toward the neutral 
sheet and lead to the generation of anomalous resistivity in the current sheet. Consequently, the 
external driving electric field penetrates into the current sheet and triggers magnetic reconnection 
at the neutral sheet.