Separation of magnetic field lines
The field lines of magnetic fields that depend on three spatial coordinates are shown to have a fundamentally different behavior from those that depend on two coordinates. Unlike twocoordinate cases, a flux tube in a magnetic field that depends on all three spatial coordinates that has a circular cross section at one location along the tube characteristically has a highly distorted cross section at other locations. In an ideal evolution of a magnetic field, the current densities typically increase. Crudely stated, if the current densities increase by a factor {sigma}, the ratio of the long to the short distance across a cross section of a flux tube characteristically increases by e{sup 2{sigma}}, and the ratio of the longer distance to the initial radius increases as e{sup {sigma}}. Electron inertia prevents a plasma from isolating two magnetic field structures on a distance scale shorter than c/{omega}{sub pe}, which is about 10 cm in the solar corona, and reconnection must be triggered if {sigma} becomes sufficiently large. The radius of the sun, R{sub CircledDotOperator }=7 MultiplicationSign 10{sup 10}cm is about e{sup 23} times larger, so when {sigma} GreaterThanOrEquivalentTo 23, two lines separated by c/{omega}{sub pe} at one location can be separated bymore »
 Authors:

^{[1]}
 Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)
 Publication Date:
 OSTI Identifier:
 22068901
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physics of Plasmas; Journal Volume: 19; Journal Issue: 11; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CURRENT DENSITY; DISTANCE; ELECTRONS; MAGNETIC FIELDS; MAGNETIC FLUX COORDINATES; PLASMA; SOLAR CORONA; SUN