Magnetic Reconnection with Asymmetry in the Outflow Direction

TL;DR

This paper analyzes magnetic reconnection with asymmetry in the outflow direction, deriving scaling relations for outflow velocity and reconnection rate, and discusses the effects of asymmetry on these processes in various plasma environments.

Contribution

It introduces a control volume analysis for steady asymmetric magnetic reconnection, providing new scaling relations for outflow velocities and clarifying the impact of asymmetry on reconnection rates.

Findings

Asymmetry does not significantly alter the reconnection rate.

Derived simple relationships for outflow velocity in different conditions.

Flow stagnation point and magnetic null do not coincide unless pressure gradient is negligible.

Abstract

Magnetic reconnection with asymmetry in the outflow direction occurs in the Earth's magnetotail, coronal mass ejections, flux cancellation events, astrophysical disks, spheromak merging experiments, and elsewhere in nature and the laboratory. A control volume analysis is performed for the case of steady antiparallel magnetic reconnection with asymmetric downstream pressure, which is used to derive scaling relations for the outflow velocity from each side of the current sheet and the reconnection rate. Simple relationships for outflow velocity are presented for the incompressible case and the case of symmetric downstream pressure but asymmetric downstream density. Asymmetry alone is not found to greatly affect the reconnection rate. The flow stagnation point and magnetic field null do not coincide in a steady state unless the pressure gradient is negligible at the flow stagnation point.