An intuitive two-fluid picture of spontaneous 2D collisionless magnetic reconnection and whistler wave generation
An intuitive and physical two-fluid picture of spontaneous 2D collisionless magnetic reconnection and whistler wave generation is presented in the framework of 3D electron-magnetohydrodynamics. In this regime, canonical circulation (Q = m_e ∇ × u + q_e B) flux tubes can be defined in analogy to magnetic flux tubes in ideal magnetohydrodynamics. Following the 3D behavior of these Q flux tubes provides a new perspective on collisionless reconnection—a perspective that has been hard to perceive via examinations of 2D projections. This shows that even in a 2D geometry with an ignorable coordinate, a 3D examination is essential for a full comprehension of the process. Intuitive answers are given to three main questions in collisionless reconnection: why is reconnection spontaneous, why do particles accelerate extremely fast, and why are whistler waves generated? Possible extensions to other regimes are discussed.
© 2018 American Institute of Physics. Received 17 November 2017; accepted 21 January 2018; published online 9 March 2018. This material is based upon work supported by the National Science Foundation under Award No. 1059519, by the Air Force Office of Scientific Research under Award No. FA9550-11-1-0184, and by the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences under Award No. DE-FG02-04ER54755.
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