Collisionless reconnection: Mechanism of self-ignition in thin current sheets

TL;DR

This paper explains how magnetic reconnection in thin collisionless current sheets spontaneously begins due to a thermal-anisotropy driven Weibel instability, which creates seed magnetic X-points.

Contribution

It identifies a novel mechanism involving thermal anisotropy and Weibel instability as the cause of self-ignition in collisionless reconnection.

Findings

Weibel mode generates seed magnetic X-points in current sheets.

Thermal anisotropy drives the onset of reconnection.

Mechanism explains spontaneous reconnection in collisionless plasmas.

Abstract

The spontaneous onset of magnetic reconnection in thin collisionless current sheets is shown to result from a thermal-anisotropy driven magnetic Weibel-mode, generating seed-magnetic field {\sf X}-points in the centre of the current layer.