Comparison of current disruption and magnetic reconnection

A T Y Lui

doi:10.1186/s40562-015-0031-2

Abstract

We examine similarities and differences between the concepts of current disruption (CD) and magnetic reconnection (MR). Both concepts have been invoked to account for explosive phenomena that involve energy transformation from magnetic field to charged particles. Similarities of these two concepts include (1) the occurrence of breakdown in magnetic connectivity, (2) magnetic energy as the primary energy source, and (3) plasma energization as a product of the process. Differences include (1) plasma flow across separatrix surfaces in an X-type magnetic field geometry being essential for MR but not for CD, (2) plasma flow ordered by the magnetic field geometry for MR but not for CD, (3) field line topology change essential for MR but not necessary for CD, and (4) CD exhibiting multifractal and symmetry breaking behavior while no such behavior has been investigated for MR. Overall, CD can be viewed as a form of generalized MR (GMR) in which the requirement for a specific magnetic field geometry and its constraint on the plasma flow pattern are removed. Therefore, the CD concept has a broader scope in applications than the MR concept alone.

Highlights

Identifying physical processes responsible for impulsive release of energy in the magnetosphere, and more generally in space plasmas, is an outstanding unsolved problem
Summary and discussion Energy transformation from magnetic field to charged particles is a challenging topic in space and astrophysics communities. Both Magnetic reconnection (MR) and current disruption (CD) have been invoked to explain impulsive release of energy in explosive phenomena observed in nature
Differences include (1) plasma flow across separatrix surfaces in an X-type magnetic field geometry regarded as essential for MR but not necessarily for CD, (2) plasma flow ordered by the magnetic field geometry for MR but not for CD, (3) field line topology change essential for MR but not necessarily for CD, and (4) CD exhibiting a multifractal and symmetry breaking behavior while no such behavior has been revealed for MR

Summary

Introduction

Identifying physical processes responsible for impulsive release of energy in the magnetosphere, and more generally in space plasmas, is an outstanding unsolved problem. These energetic processes call for the breakdown of the frozen-in-field condition such that magnetic energy can be transformed to charged particle energy.

Results

Conclusion