New Measure of the Dissipation Region in Collisionless Magnetic Reconnection

TL;DR

This paper introduces a Lorentz-invariant measure to identify the small-scale dissipation region in collisionless magnetic reconnection, validated through simulations across various configurations.

Contribution

It proposes a novel, Lorentz-invariant scalar measure for dissipation regions in collisionless magnetic reconnection, applicable in diverse simulation setups.

Findings

Accurately locates the dissipation region in simulations.

Validates the measure in symmetric and asymmetric reconnection.

Discusses implications for nonideal MHD dissipation.

Abstract

A new measure to identify a small-scale dissipation region in collisionless magnetic reconnection is proposed. The energy transfer from the electromagnetic field to plasmas in the electron's rest frame is formulated as a Lorentz-invariant scalar quantity. The measure is tested by two-dimensional particle-in-cell simulations in typical configurations: symmetric and asymmetric reconnection, with and without the guide field. The innermost region surrounding the reconnection site is accurately located in all cases. We further discuss implications for nonideal MHD dissipation.