Measures Of Diffusion Regions Applied To PIC Reconnection Simulations

Abstract:

The primary goal of the current NASA-MMS mission is to "identify and study diffusion regions during magnetic reconnection in Earth's magnetopause and magnetotail. Yet the term diffusion region is often misunderstood and can be ambiguous. Different conditions for a region to be a "diffusion region" are interpreted theoretically, related to each other and applied to PIC simulations of tail reconnection^(a) (and to MMS measurements, if possible, at time of AGU). None of the conditions is both necessary and sufficient for topological reconnection to occur.  During magnetic reconnection in a kinetic plasma key differences exist between the locations of diffusion regions in the electron fluid, the ion fluid and a single (MHD) fluid.

^(a)M.V. Goldman, D.L. Newman and G. Lapenta, Space Science Reviews, 2015