Magnetic reconnection during collisionless, stressed, X-point collapse using Particle-in-Cell simulation

Abstract

Two cases of weakly and strongly stressed X-point collapse were considered. Here descriptors weakly and strongly refer to 20 % and 124 % unidirectional spatial compression of the X-point, respectively. In the weakly stressed case, the reconnection rate, defined as the out-of-plane electric field in the X-point (the magnetic null) normalised by the product of external magnetic field and Alfvén speeds, peaks at 0.11, with its average over 1.25 Alfvén times being 0.04. Electron energy distribution in the current sheet, at the high energy end of the spectrum, shows a power law distribution with the index varying in time, attaining a maximal value of -4.1 at the final simulation time step (1.25 Alfvén times). In the strongly stressed case, magnetic reconnection peak occurs 3.4 times faster and is more efficient. The peak reconnection rate now attains value 2.5, with the average reconnection rate over 1.25 Alfvén times being 0.5. The power law energy spectrum for the electrons in the current sheet attains now a steeper index of -5.5, a value close to the ones observed in the vicinity of X-type region in the Earth's magneto-tail. Within about one Alfvén time, 2% and 20% of the initial magnteic energy is converted into heat and accelerated particle energy in the case of weak and strong stress, respectively. In the both cases, during the peak of the reconnection, the quadruple out-of-plane magnetic field is generated, hinting possibly to the Hall regime of the reconnection. These results strongly suggest the importance of the collionless, stressed X-point collapse as a possible contributing factor to the solution of the solar coronal heating problem or more generally, as an efficient mechanism of converting magnetic energy into heat and super-thermal particle energy.

Final Accepted Version (Physics of Plasmas in Press 2007)

References in corpus (4)

• Physical Origin of the Quadrupole Out-of-Plane Magnetic Field in Hall-MHD Reconnection
• Formation of Power-law Energy Spectra in Space Plasmas by Stochastic Acceleration due to Whistler-Mode Waves
• Particle-In-Cell simulations of circularly polarised Alfvén wave phase mixing: a new mechanism for electron acceleration in collisionless plasmas
• Phase mixing of shear Alfven waves as a new mechanism for electron acceleration in collisionless, kinetic plasmas

Cited by in corpus (19)

• Recent Advances in Understanding Particle Acceleration Processes in Solar Flares
• Three-dimensional oscillatory magnetic reconnection
• 3D magnetic reconnection and its application to solar flares
• Particle acceleration in a reconnecting current sheet: PIC simulation
• Electron heating and acceleration by magnetic reconnection in hot accretion flows
• Explosive X-point collapse in relativistic magnetically-dominated plasma
• Accelerated particle beams in a 3D simulation of the quiet Sun
• Physics of collisionless reconnection in a stressed X-point collapse
• Implosive collapse about magnetic null points: A quantitative comparison between 2D and 3D nulls
• Physics of collisionless phase mixing
• The effect of guide-field and boundary conditions on collisionless magnetic reconnection in a stressed X-point collapse
• A new fast reconnection model in a collisionless regime
• Octupolar out-of-plane magnetic field structure generation during collisionless magnetic reconnection in a stressed X-point collapse
• Resistively-limited current sheet implosions in planar anti-parallel (1D) and null-point containing (2D) magnetic field geometries
• Missing bits of the solar jigsaw puzzle: small-scale, kinetic effects in coronal studies
• The effects of ion mass variation and domain size on octupolar out-of-plane magnetic field generation in collisionless magnetic reconnection
• Role of Electron Inertia and Reconnection Dynamics in a Stressed X-point Collapse with a Guide-Field
• Hamiltonian formulation of X-point collapse in an extended magnetohydrodynamics framework
• Turbulent Plasmoid Reconnection