Magnetic nulls in interacting dipolar fields

  title={Magnetic nulls in interacting dipolar fields},
  author={Todd Elder and Allen H. Boozer},
  journal={Journal of Plasma Physics},
The prominence of nulls in reconnection theory is due to the expected singular current density and the indeterminacy of field lines at a magnetic null. Electron inertia changes the implications of both features. Magnetic field lines are distinguishable only when their distance of closest approach exceeds a distance $\varDelta _d$. Electron inertia ensures $\varDelta _d\gtrsim c/\omega _{pe}$. The lines that lie within a magnetic flux tube of radius $\varDelta _d$ at the place where the field… 
1 Citations

Local analysis of fast magnetic reconnection

Fast magnetic reconnection is defined by the topology of the magnetic field lines changing on a timescale that is approximately an order of magnitude longer than the topology-conserving



MHD Structures in Three-Dimensional Reconnection

This review of three-dimensional reconnection focusses on the MHD aspects of the process. It describes the different structures where current tends to concentrate and so lead to reconnection, namely,

Forced magnetic reconnection

By studying a simple model problem, the time evolution of magnetic field islands which are induced by perturbing the boundary surrounding an incompressible plasma with a resonant surface inside is

The structure of the exosphere or adventures in velocity space, in Geophysics

  • 1963

and E

  • R. 11 Priest, The structure of three-dimensional magnetic neutral points, Phys. Plasmas 3, 759
  • 1996

Simple magnetic reconnection example

In laboratory and natural plasmas of practical interest, the smallest spatial scale $\Delta_d$ over which magnetic field lines are distinguishable on the time scale set by an ideal evolution differs

Magnetic reconnection and thermal equilibration

When a magnetic field is forced to evolve on a time scale $\tau_{ev}$, as by footpoint motions driving the solar corona or non-axisymmetric instabilities in tokamaks, the magnetic field lines undergo

Magnetic reconnection with null and X-points

Null and X-points of magnetic fields are places at which magnetic field lines with fundamentally different topologies approach each other arbitrary closely before separating by a distance set by the

Current density and plasma displacement near perturbed rational surfaces

The current density in the vicinity of a rational surface of a force-free magnetic field subjected to an ideal perturbation is shown to be the sum of both a smooth and a delta-function distribution,

The 3D topology and interaction of complex magnetic flux systems

Abstract In order to understand the topology of complex flux systems we analyse in detail the rich structural properties of the magnetic field created in turn by two or three balanced or unbalanced

Interplanetary Magnetic Field and the Auroral Zones

Abstract : It was found that a model with a southward interplanetary magnetic field leads to a natural explanation of the SD currents. Speculative aspects of the problem as they appear at this time