Plasmoid-associated energetic ion burst in the deep magnetotail: Numerical modeling of the boundary layer
- Max-Planck-Institut fuer Physik und Astrophysik, Garching (West Germany)
Single particle orbits are numerically followed in a time dependent two-dimensional resistive (MHD) model of tail reconnection. In this model, near-Earth reconnection disconnects the plasma sheet and the tailward departing closed field line region is surrounded by a thickening layer of disconnected lobe field lines. Orbits starting in this layer are traced backward in time, and their interaction with the current sheet close to the X line is studied. The model predicts the spatial distribution of energetic protons in the boundary layer surrounding plasmoids. It is argue that lower energy protons are injected after their acceleration onto lobe field lines closer to the neutral line than higher energy ions. Thus the low-energy proton boundary layer will be found closer to the separatrix than the higher energy proton layer. This is confirmed by the numerical calculations. Further downtail from the neutral line the energy dispersion due to the dawn-dusk electric field becomes larger and leads to the usual inward dispersion. Applying Liouville's theorem, the authors calculate the distribution function of accelerated ions in the boundary layer. Comparison with measurements obtained in the deep tail indicates that proton intensities observed in the layer around plasmoids at energies above {approximately} 30 keV can be obtained by the neutral line acceleration of a suitable lobe ion distribution.
- OSTI ID:
- 5916272
- Journal Information:
- Journal of Geophysical Research; (USA), Journal Name: Journal of Geophysical Research; (USA) Vol. 94:A3; ISSN 0148-0227; ISSN JGREA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
BARYONS
BOUNDARY LAYERS
CHARGED PARTICLES
COMPARATIVE EVALUATIONS
DISTRIBUTION
DISTRIBUTION FUNCTIONS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELEMENTARY PARTICLES
FERMIONS
FUNCTIONS
HADRONS
IONS
LAYERS
MAGNETIC BAYS
MAGNETIC RECONNECTION
MAGNETOTAIL
MATHEMATICAL MODELS
NUCLEONS
NUMERICAL SOLUTION
PLASMA SHEET
PLASMOIDS
PROTONS
SPATIAL DISTRIBUTION
TIME DEPENDENCE
TWO-DIMENSIONAL CALCULATIONS