Particle acceleration at a reconnecting magnetic separator

Abstract

While the exact acceleration mechanism of energetic particles during solar flares is (as yet) unknown, magnetic reconnection plays a key role both in the release of stored magnetic energy of the solar corona and the magnetic restructuring during a flare. Recent work has shown that special field lines, called separators, are common sites of reconnection in 3D numerical experiments. To date, 3D separator reconnection sites have received little attention as particle accelerators. We investigate the effectiveness of separator reconnection as a particle acceleration mechanism for electrons and protons. We study the particle acceleration using a relativistic guiding-centre particle code in a time-dependent kinematic model of magnetic reconnection at a separator. The effect upon particle behaviour of initial position, pitch angle and initial kinetic energy are examined in detail, both for specific (single) particle examples and for large distributions of initial conditions. The separator reconnection model contains several free parameters and we study the effect of changing these parameters upon particle acceleration, in particular in view of the final particle energy ranges which agree with observed energy spectra.

17 pages, 12 figures. Accepted for publication in A&A

References in corpus (17)

• An Observational Overview of Solar Flares
• Three-dimensional magnetic reconnection regimes: A review
• Microflares and the Statistics of X-ray Flares
• Local re-acceleration and a modified thick target model of solar flare electrons
• Satellite Observations of Separator Line Geometry of Three-Dimensional Magnetic Reconnection
• Particle Acceleration in an Evolving Network of Unstable Current Sheets
• Particle acceleration and transport in reconnecting twisted loops in a stratified atmosphere
• Particle Acceleration in Multiple Dissipation Regions
• Magnetohydrodynamic evolution of magnetic skeletons
• Particle trajectories and acceleration during 3D fan reconnection
• Effect of collisions and magnetic convergence on electron acceleration and transport in reconnecting twisted solar flare loops
• Kinetic modeling of particle acceleration in a solar null point reconnection region
• Solar Particle Acceleration at Reconnecting 3D Null Points
• A time-dependent model for magnetic reconnection in the presence of a separator
• Particle energisation in a collapsing magnetic trap model: the relativistic regime
• The nature of separator current layers in MHS equilibria I. Current parallel to the separator
• Gyrokinetic electron acceleration in the force-free corona with anomalous resistivity

Cited by in corpus (7)

• Combining MHD and kinetic modelling of solar flares
• Particle acceleration at reconnecting separator current layers
• Flare particle acceleration in the interaction of twisted coronal flux ropes
• Particle Acceleration in Collapsing Magnetic Traps with a Braking Plasma Jet
• Particle dynamics in a non-flaring solar active region model
• Particle acceleration with anomalous pitch angle scattering in 3D separator reconnection
• Relativistic Guiding-Center Motion: Action Principle, Kinetic Theory, and Hydrodynamics