Plasma dynamics on current-carrying magnetic flux tubes

Journal Article · Sun Mar 01 00:00:00 EST 1992 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JA02700· OSTI ID:5556827

Swift, D W ^[1]

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1. Univ. of Alaska, Fairbanks (United States)

The evolution of plasma in a current-carrying magnetic flux tube of variable cross section is investigated using a one-dimensional numerical simulation. The flux tube is narrow at the two ends and broad in the middle. The middle region of the flux tube is loaded with a hot plasma population, and the two ends have a much more dense gravitationally bound plasma. The result is that the number of particles per unit of flux tube length has a minimum near each end and a maximum in the middle where the flux tube has the largest cross section. A large potential difference, parallel to the magnetic field, is applied across the domain. The general result is that density minimum tends to deepen, primarily in the cathode end, and the entire potential drop becomes concentrated across the region of density minimum. The potential drop is maintained primarily by electron inertia. The evolution of the simulation shows some sensitivity to particle boundary conditions, but the simulations inevitably evolve into a final state with a nearly stationary double layer near the cathode end. The simulation results are at sufficient variance with observations that it appears unlikely that auroral electrons can be explained by a simple process of acceleration through a field-aligned potential drop.

• OSTI ID: 5556827
• Journal Information: Journal of Geophysical Research; (United States), Vol. 97:A3; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EARTH MAGNETOSPHERE
MAGNETOHYDRODYNAMICS
AURORAE
COMPUTERIZED SIMULATION
ELECTRIC CURRENTS
ELECTRONS
IONOSPHERE
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FLUX
PLASMA
PLASMA DENSITY
SOLAR ATMOSPHERE
ATMOSPHERES
CURRENTS
EARTH ATMOSPHERE
ELEMENTARY PARTICLES
FERMIONS
FLUID MECHANICS
HYDRODYNAMICS
LEPTONS
MECHANICS
PLANETARY IONOSPHERES
SIMULATION
661320* - Auroral
Ionospheric
& Magnetospheric Phenomena- (1992-)