Self-focusing of local plasma currents

Abstract

For a Boltzmann distribution function, neglecting collisions and in the presence of a longitudinal external magnetic field, the self-consistent equilibrium configuration is found for a plasma with components s; this configuration represents an infinitely extended plane layer consisting of periodically recurring quasi-filaments of current for each of which the Bennett self-focusing condition I = 2 θs/qsβs is fulfilled. The filaments may be considered the result of the continuous topological transformation of a homogeneous plane layer having the characteristic dimension kg02 = 2 π n0 Σ (qs2 βs2/θs2) since the condition indicated is fulfilled for an element of the homogeneous layer in the range —∞≤ x ≤∞, —π/kg0 ≤ y ≤ π/kg0. During this transformation the characteristic dimensions, the total current and the energy of the y component of the magnetic field of the filaments remain constant. With increasing depth of the modulation, characterized by the parameter only the energy of the x component of the magnetic field grows (proportionally to y in the linear case).The authors examined the stability of a homogeneous plane layer with respect to perturbations of the type jz=jz(x) exp (ωt+i ky), as well as the factors giving rise to filaments and their in high current discharge processes.

Towards a scalable fully-implicit fully-coupled resistive MHD formulation with stabilized FE methods

“…The corresponding linear stability problem is the classical hyrdromagnetic Rayleigh-Bernard problem. The final example is a driven magnetic reconnection problem where a Fadeev magnetic field equilibrium [113], which features islands embedded in a Harris current sheet, that undergoes a transient reconfiguration of the magnetic field. The computational timing results presented in this section were obtained on the Red Storm Cray XT3/4 computer at Sandia National Laboratories.…”

Kinetic simulations of plasmoid chain dynamics

“…This approach is different from the initial condition used in previous two-dimensional Particle-in-Cell simulations [6,35]. These studies used the island-chain equilibrium, or Fadeev equilibrium [36], that imposes the initial presence of spatially larger scale magnetic islands where the coalescence process involves larger scale plasmoids and proceeds at a slower pace with respect to our simulations. …”

Role of Ion Kinetic Physics in the Interaction of Magnetic Flux Ropes

“…These results have conceivable implications for real reconnecting systems in which coupling of micro to macro-scale physics is important, such as the Earth's magnetosphere. All of the simulations described are initialised with a magnetic island equilibrium [28], with similar parameters to a recent study [16]. The initial magnetic potential is…”