# Two-scale structure of the electron dissipation region during collisionless magnetic reconnection

## TL;DR

This paper uses PIC simulations to reveal a two-scale structure in the electron dissipation region during collisionless magnetic reconnection, showing a decoupled high-velocity electron jet and consistent fast reconnection rates.

## Contribution

It uncovers a novel two-scale structure of the electron dissipation region and demonstrates that reconnection remains fast regardless of system size or boundary conditions.

## Key findings

- Electron dissipation region develops a two-scale structure.
- Electron outflow jet remains decoupled and extends far downstream.
- Reconnection rate remains fast independent of system size.

## Abstract

Particle in cell (PIC) simulations of collisionless magnetic reconnection are presented that demonstrate that the electron dissipation region develops a distinct two-scale structure along the outflow direction. The length of the electron current layer is found to decrease with decreasing electron mass, approaching the ion inertial length for a proton-electron plasma. A surprise, however, is that the electrons form a high-velocity outflow jet that remains decoupled from the magnetic field and extends large distances downstream from the x-line. The rate of reconnection remains fast in very large systems, independent of boundary conditions and the mass of electrons.