Particle simulation study of driven magnetic reconnection in a collisionless plasma

TLDR

Magnetic reconnection proceeds in two stages: an early slow phase when the ion current layer thins to the ion meandering orbit scale, followed by a late fast phase when the electron current concentrates to the electron meandering orbit scale. The study investigates collisionless driven reconnection in a collisionless plasma using two‑and‑one‑half‑dimensional particle simulations. The simulations model the evolution of the ion and electron current layers to capture the physics of collisionless driven reconnection. The results show that the global dynamics are governed by the ion current layer, the peak reconnection rate scales with the driving electric field, and both ion and electron heating occur with ion temperatures reaching at least twice the electron temperature.

Abstract

Driven magnetic reconnection in a collisionless plasma, ‘‘collisionless 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 spatial scale comparable to the orbit amplitude of an electron meandering motion (electron current layer). The global dynamic evolution of magnetic reconnection is controlled by the physics of the ion current layer. The maximum reconnection rate is roughly in proportion to the driving electric field. It is also found that both ion heating and electron heating take place in accordance with the formation of two current layers and the ion temperature becomes two or more times as high as the electron temperature.