Marc Swisdak
University of Maryland
Simulations and Observations of Non-Thermal Energization of Protons in the Near-Sun Heliospheric Current Sheet
Numerical simulations of magnetic reconnection in macroscale systems with the kglobal model produce extended power-law distributions of both electrons and protons. We will discuss the model, the mechanisms controlling the relative heating and non-thermal energization of electrons and protons, and the maximum energies that can be obtained. Then we will discuss observations of energetic protons being accelerated above∼400 keV within the reconnection exhaust of a heliospheric current sheet crossing by NASA’s Parker Solar Probe at a distance of∼16.25 solar radii from the Sun. The differential energy spectrum of the protons contained a power law at high energies with a spectral index of ∼-5, which is matched by supporting simulations with kglobal. The trapping and acceleration of protons in the reconnection exhaust are likely facilitated by merging magnetic islands with a guide field to reconnecting field ratio of between 0.2 and 0.3.