Statistical description of coalescing magnetic islands via magnetic reconnection

Abstract

The physical picture of interacting magnetic islands provides a useful paradigm for certain plasma dynamics in a variety of physical environments, such as the solar corona, the heliosheath, and the Earth's magnetosphere. In this work, we derive an island kinetic equation to describe the evolution of the island distribution function (in area and in flux of islands) subject to a collisional integral designed to account for the role of magnetic reconnection during island mergers. This equation is used to study the inverse transfer of magnetic energy through the coalescence of magnetic islands in 2D. We solve our island kinetic equation numerically for three different types of initial distribution: delta-distribution, Gaussian and power-law distribution. The time evolution of several key quantities is found to agree well with our analytical predictions: magnetic energy decays as ${\tilde{t}}^{-1}$, the number of islands decreases as ${\tilde{t}}^{-1}$, and the averaged area of islands grows as $\tilde{t}$, where $\tilde{t}$ is the time normalized to the characteristic reconnection time scale of islands. General properties of the distribution function and the magnetic energy spectrum are also studied.

38 pages; 10 figures; Accepted by Journal of Plasma Physics

References in corpus (25)

• Instability of current sheets and formation of plasmoid chains
• On the structure of relativistic collisionless shocks in electron-ion plasmas
• Observation of An Evolving Magnetic Flux Rope Prior To and During A Solar Eruption
• Highly Efficient Modeling of Dynamic Coronal Loops
• The Mechanisms of Electron Heating and Acceleration during Magnetic Reconnection
• Self-Feeding Turbulent Magnetic Reconnection on Macroscopic Scales
• Blazar flares powered by plasmoids in relativistic reconnection
• Nonhelical inverse transfer of a decaying turbulent magnetic field
• The role of three-dimensional transport in driving enhanced electron acceleration during magnetic reconnection
• A Review of the 0.1 Reconnection Rate Problem
• Classes of hydrodynamic and magnetohydrodynamic turbulent decay
• A model of acceleration of Anomalous Cosmic Rays by Reconnection in the Heliosheath
• Saturation mechanism of the Weibel instability in weakly magnetized plasmas
• Collisionless Reconnection in Magnetohydrodynamic and Kinetic Turbulence
• On the Distribution of Plasmoids In High-Lundquist-Number Magnetic Reconnection
• Inverse cascade of non-helical magnetic turbulence in a relativistic fluid
• Magnetohydrodynamic turbulence mediated by reconnection
• Observations of Magnetic Reconnection in the Transition Region of Quasi-Parallel Shocks
• Determining the Dominant Acceleration Mechanism during Relativistic Magnetic Reconnection in Large-scale Systems
• Magnetic Energy Release, Plasma Dynamics, and Particle Acceleration during Relativistic Turbulent Magnetic Reconnection
• Secondary Energization in Compressing Plasmoids during Magnetic Reconnection
• Relativistic Nonthermal Particle Acceleration in Two-Dimensional Collisionless Magnetic Reconnection
• Inverse energy transfer in decaying, three dimensional, nonhelical magnetic turbulence due to magnetic reconnection
• On the ions acceleration via collisionless magnetic reconnection in laboratory plasmas
• Spontaneous magnetization of collisionless plasma through the action of a shear flow

Cited by in corpus (5)

• Reconnection-driven flares in 3D black hole magnetospheres -- A scenario for hot spots around Sagittarius A*
• Scaling of the Hosking integral in decaying magnetically-dominated turbulence
• Resistively controlled primordial magnetic turbulence decay
• Parameter study of decaying magnetohydrodynamic turbulence
• Spontaneous magnetization of collisionless plasma through the action of a shear flow