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Detailed Reference Information |
Barbosa, D.D. (1993). Thermal structure of ions and electrons in Saturn's inner magnetosphere. Journal of Geophysical Research 98: doi: 10.1029/93JA00478. issn: 0148-0227. |
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A theoretical model of thermal ion and electron temperatures in Saturn's inner magnetospheres is presented. The model is based on a fast mode of radial diffusive plasma transport with a diffusion time scale which varies with distance as &tgr;D=2¿106 s (6/L)3. Such a model provides a conceptual organization to the energy balance problem in that the plasma residence time in the region L>4.5 is short compared to the time scale for Coulomb energy exchange and radiative losses, where as the opposite is true in the region L<4.5. This condition implies that in the Dione--Tethys plasma torus the ion and electron temperatures reflect their initial values upon creation out of the neutral H2O cloud distributed throughout the region. Oxygen ions thus have a temperature corresponding to local pickup by the magnetic field and a large perpendicular temperature anisotropy, while electrons have a temperature corresponding to that of ionization secondaries created by electron impact dissociation/ionization of H2O by the ambient hot electron population. In the collisional L<4.5 regime the ion temperature is controlled by local pickup from O+-O charge exchange, while the electron temperatures is controlled by heating from thermal O+ ions against radiative losses from electron-excited OII. A calculation of the off-equatorial behavior of density and temperature in the Dione--Tethys torus based on the assumption of a constant ion temperature anisotropy along field lines is also described. The model successfully reproduces the decrease with latitude in electron and O+ temperatures which occur as a result of the interaction of electrons with the ambipolar electric potential and O+ ions with the centrifugal potential. ¿ American Geophysical Union 1993 |
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BACKGROUND DATA FILES |
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Abstract |
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Keywords
Magnetospheric Physics, Planetary magnetospheres, Magnetospheric Physics, Magnetosphere interactions with satellites and rings, Magnetospheric Physics, Magnetospheric configuration and dynamics, Space Plasma Physics, Ionization processes |
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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 |
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