On the Micro-Macro Coupling of Mass Loading Magnetic Reconnection with Cold Ions

Abstract:

It is well established that the process of magnetic reconnection is influenced by the constituent particles of the participating plasma. In this study we investigate how magnetic reconnection behaves when a dense population of cold ions is added to the inflow region. Using 2.5D Particle-In-Cell simulations, we compare two reconnection events, one containing the cold population and one without, in order to investigate how the process is influenced by the added population. We find that mass loading the inflow region with cold ions changes the reconnection process on both global and kinetic scales. We show that these changes on different scales are related through kinetic processes in the ion diffusion region, and we describe the micro-macro coupling of mass loading. On macro scales the reconnection rate is reduced through mass loading, which corresponds to a reduction in the aspect ratio of the ion diffusion region on micro scales. By investigating the micro physics of the ion diffusion region further, we identify the cold ion inertia to be the significant link that connects the changes on different scales.