Open AccessProton acceleration in antiparallel collisionless magnetic reconnection: Kinetic mechanisms behind the fluid dynamics
Author(s) -
Aunai N.,
Belmont G.,
Smets R.
Publication year - 2011
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2011ja016688
Subject(s) - physics , proton , antiparallel (mathematics) , magnetic reconnection , kinetic energy , magnetic field , acceleration , electric field , anisotropy , classical mechanics , mechanics , atomic physics , quantum electrodynamics , nuclear physics , quantum mechanics
This paper investigates the proton kinetic mechanisms leading to the formation of plasma jets in antiparallel magnetic reconnection. In particular, the interaction of the protons with the Hall electric field in the proton non‐ideal region is discussed. The study, based on a two‐dimensional hybrid simulation, details the important role of the proton pressure force in the acceleration process and its role in maintaining open and steady the proton outflow channel. When no fluid closure is assumed, it is found that this force arises from a strong anisotropy in velocity space which comes from kinetic effect. By analyzing the distribution functions and the individual particle dynamics, it is shown that the mixing of protons bouncing in a divergent electrostatic potential well associated to the Hall effect statistically couples the two in‐plane velocity components of the particles. This coupling results, from the macroscopic point of view, in off‐diagonal components of the pressure tensor.