Phase space structure of the electron diffusion region in reconnection with weak guide fields

Kinetic simulations of magnetic reconnection provide detailed information about the electric and magnetic structure throughout the simulation domain, as well as high resolution profiles of the essential fluid parameters including the electron and ion densities, flows, and pressure tensors. However, the electron distribution function, f(v), within the electron diffusion region becomes highly structured in the three dimensional velocity space and is not well resolved by the data available from the particle-in-cell (PIC) simulations. Here, we reconstruct the electron distribution function within the diffusion region at enhanced resolution. This is achieved by tracing electron orbits in the fields taken from PIC simulations back to the inflow region where an analytic form of the magnetized electron distribution is known. For antiparallel reconnection, the analysis reveals the highly structured nature of f(v), with striations corresponding to the number of times electrons have been reflected within the reconne...

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