|
Detailed Reference Information |
Singh, N. and Chaganti, V.S. (1994). Electron collection by a highly positive satellite in the ionosphere: Test particle simulation. Journal of Geophysical Research 99: doi: 10.1029/93JA01642. issn: 0148-0227. |
|
Collection of electrons by a satellite at a relatively high potential in low Earth orbit, including the effects of the satellite's orbital motion, remains a poorly understood phenomenon. Using a test particle simulation in which charged particle motion is tracked in prescribed electric fields, we calculate here the current collection and the nature of the energy distribution function of the electrons collected by the satellite, including the effects of the satellite orbital motion. Calculations of the collected current without the orbital motion show an excellent agreement with the current from the Parker-Murphy model, but with the orbital motion of the satellite the current collection is enhanced, the degree of enhancement depending on the size of the satellite sheath extending along the magnetic field line. In the latter case, the flow of electrons around the satellite shows some interesting behaviors including azimuthal E¿B drift around the satellite, axial trapping along the magnetic field, and formation of field-aligned flow of electrons in the wake region. The total energy of the collected electrons is ≂eϕ0, where ϕ0 is the satellite potential, but the partition of the energy into components parallel (W∥) and perpendicular (W⊥) to the magnetic field shows interesting features. For the magnetic field along the polar axis Z, the energy distributions near the poles are perfectly field aligned, that is, the parallel energy W∥=eϕ0. The perpendicular component (W⊥) progressively increases toward the ''equator'' of the spherical satellite. For a sufficiently large bias potential ϕ0, the equatorial energy distributions f(W∥) and f(W⊥) show fine structures having multiple peaks. These features of the distribution functions result from the chaotic motion of electrons and the associated coupling between the electron motions parallel and perpendicular to the magnetic field in strongly nonuniform electric fields near the satellite. ¿ American Geophysical Union 1994 |
|
|
|
BACKGROUND DATA FILES |
|
|
Abstract |
|
|
|
|
|
Keywords
Ionosphere, Electric fields and currents, Space Plasma Physics, Charged particle motion and acceleration, Space Plasma Physics, Numerical simulation studies, Space Plasma Physics, Spacecraft sheaths, wakes, charging |
|
Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
|
|
|