Particle Energization During Magnetic Reconnection With a Novel Computational Model

Abstract:

A new computational model, kglobal, describes the energization of non-thermal electrons during magnetic reconnection. Previous work has shown that kinetic scales are unimportant for this process since Fermi reflection within magnetic islands, which occurs on large scales, dominates the effects of small-scale parallel electric field. The computational system includes fluid ions, fluid electrons, and electron macroparticles that follow the guiding center equations. We will discuss the derivation of the underlying equations and show that they correctly describe the firehose instability, whose dynamics plays
a key role in throttling reconnection. Simulations using the model have accurately simulated Alfven waves, magnetohydrodynamic waves, the firehose instability, and the Landau damping of electron acoustic modes. Simulations of reconnection in 2d3v (i.e., with an invariant direction) produce multiple magnetic islands in which energetic electrons acquire heated anisotropic temperatures (parallel greater than perpendicular) as well as power law spectra. Comparisons with kinetic reconnection simulations will be discussed as well as possible extensions to 3D.