The scaling of forced collisionless reconnection in two and three dimensions

TL;DR

This study investigates how forced magnetic reconnection behaves in collisionless plasmas using 2D and 3D simulations, revealing that strong forcing leads to Alfvenic reconnection with stable dissipation region geometry.

Contribution

It provides the first comparison of forced reconnection dynamics in 2D and 3D collisionless plasmas with finite electron inertia.

Findings

Reconnection becomes Alfvenic at strong forcing in both 2D and 3D.

The dissipation region maintains an aspect ratio around 0.15.

Reconnection inflow velocities scale with the Alfven speed.

Abstract

This paper presents two-fluid simulations of forced magnetic reconnection with finite electron inertia in a collisionless three-dimensional (3D) cube with periodic boundaries in all three directions. Comparisons are made to analogous two-dimensional (2D) simulations. Reconnection in this system is driven by a spatially localized forcing function that is added to the ion momentum equation inside the computational domain. Consistent with previous results in similar, but larger forced 2D simulations [B. Sullivan, B. N. Rogers, and M. A. Shay, Phys. Plasmas 12, 122312 (2005)], for sufficiently strong forcing the reconnection process is found to become Alfvenic in both 2D and 3D, i.e., the inflow velocity scales roughly like some fraction of the Alfven speed based on the upstream reconnecting magnetic field, and the system takes on a stable configuration with a dissipation region aspect ratio on the order of 0.15.