Turbulent energization of electron power law tails during magnetic reconnection

TL;DR

This study uses 3D particle-in-cell simulations to explore how turbulence during magnetic reconnection in Earth's magnetotail leads to the formation of electron power law tails, highlighting the role of turbulent energy exchange rather than direct electric field acceleration.

Contribution

It provides a comprehensive explanation of how turbulent outflows during reconnection create conditions for electron power law tail formation, using high-resolution 3D simulations.

Findings

Electron energization is diffuse and enhanced near magnetic structures.

Power law tails form through turbulent energy exchange, not direct acceleration.

Turbulence-driven processes dominate electron energization during reconnection.

Abstract

Earth's magnetotail is an excellent laboratory to study the interplay of reconnection and turbulence in determining electron energization. The process of formation of a power law tail during turbulent reconnection is a documented fact still in need of a comprehensive explanation. We conduct a massively parallel particle in cell 3D simulation and use enhanced statistical resolution of the high energy range of the particle velocities to study how reconnection creates the conditions for the tail to be formed. The process is not direct acceleration by the coherent, laminar, reconnection-generated electric field. Rather, reconnection causes turbulent outflows where energy exchange is dominated by a highly non-gaussian distribution of fluctuations. Electron energization is diffuse throughout the entire reconnection outflow but it is heightened by regions of intensified magnetic field such as dipolarization fronts traveling towards Earth.