PARTICLE SIMULATION STUDY OF DRIVEN MAGNETIC RECONNECTION IN A COLLISIONLESS PLASMA

Driven magnetic reconnection in a collisionless plasma, ''collisionles s driven reconnection,'' is investigated by means of two-and-one-half- dimensional particle simulation. Magnetic reconnection develops in two steps, i.e., slow reconnection, which takes place in the early stage of the compression when the current layer is compressed as thin as the orbit amplitude of an ion meandering motion (ion current layer), and subsequent fast reconnection, which takes place in the late stage when the electron current is concentrated into the narrow region with a sp atial scale comparable to the orbit amplitude of an electron meanderin g motion (electron current layer). The global dynamic evolution of mag netic reconnection is controlled by the physics of the ion current lay er. The maximum reconnection rate is roughly in proportion to the driv ing electric field. It is also found that both ion heating and electro n heating take place in accordance with the formation of two current l ayers and the ion temperature becomes two or more times as high as the electron temperature.