Statistical properties of energy dissipation in magnetic structures during turbulent reconnection in the Earth's magnetotail and 3D Particle-In-Cell simulations

Magnetic reconnection is a ubiquitous plasma phenomenon that plays an important role in particle energization. The conversion process of magnetic energy into particle energies has been studied extensively in recent years, albeit mostly on a theoretical or case-by-case basis observationally. In this work, we conduct a statistical study using data from the Magnetospheric Multiscale (MMS) mission, and detail the particle energization mechanisms in electron-scale magnetic structures found near reconnecting regions in turbulent Earth's magnetotail using a unique detection algorithm [1]. In contrast to the conventional picture of unidirectional energy transfer to particles by laminar 2D reconnection, we find that energy exchange within magnetic structures tends to be bidirectional with only a small positive bias from magnetic field to particles [2]. Specific electron energization mechanisms are quantified including those due to parallel electric field, Fermi energization due to curvature drift, betatron heating from magnetic field inhomogeneity, and polarization drift. These statistical properties are largely reproduced [3] by 3D Particle-In-Cell simulations of kinetic reconnection with a varying strength of guide field [4]. We will discuss which specific aspects of 2D laminar physics carry over to 3D and which do not. [1] K. Bergstedt et al. GRL 47, e2020GL088540 (2020). [2] R. Wang et al. to be submitted (2025). [3] G. Li et al. this conference. [4] X. Li et al. ApJ 884, 118 (2019).