Space and Cosmic Ray Physics Seminar

Calendar
Department of Physics Calendar
Date
Sep 21, 2026 4:30pm - 5:30pm

Description

Title: Simulations and Observations of Non-Thermal Energization of Protons in the Near-Sun Heliospheric Current Sheet

Speaker: Marc Swisdak, University of Maryland

Abstract: 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.

Notes: Join the meeting at 4:15 for meet and greet.
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