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Title: General characteristics of hot plasma and energetic particles in the Saturnian magnetosphere: Results from the Voyager spacecraft

Journal Article · · J. Geophys. Res.; (United States)

The low energy charged particle (LECP) experiment on the Voyager 1 and 2 spacecraft made measurements of the intensity, energy spectra, and spatial distributions of ions (30 keV< or approx. =E< or approx. =150 MeV) and electrons (22 keV< or approx. =E< or approx. =20 MeV) during encounters with the Saturnian magnetosphere in November 1980 and August 1981, respectively. Detailed analysis of the data has revealed the following: (1) Energetic ions are present in the interplanetary medium both upstream (to approx. 200 R/sub S/) and off the dawn bow shock (to approx.400 R/sub S/) of the magnetosphere, with maximum energies approx.100 keV. (2) Low-energy (> or approx. =22 keV) electrons are generally depleted inward of Lapprox.R/sub S/, while low-energy (> or approx. =30 keV) ions are greatly enhanced in the same region. (3) The composition of low-energy ions is most likely domeinated by protons in the outer magnetosphere but is consistent with oxygen in the inner (L< or approx. =9) magnetosphere. (4) The ion spectrum is described well by the kappa distribution with characteristic temperatures kT/sub H/ ranging from approx.15 to approx.55 keV; the hot plasma region is generally confined between the L shells of Tethys and Rhea but exhibits substantial variability. (5) The electron energy spectrum at L< or approx. =10 develops a secondary peak at E> or approx. =200 keV that shifts to higher (approx.1 MeV) energies inside the orbits of Enceladus and Mimas, indicative of electron resonance interactions with the planetary satellites.

Research Organization:
Applied Physics Laboratory, Johns Hopkins University
OSTI ID:
5123741
Journal Information:
J. Geophys. Res.; (United States), Vol. 88:A11
Country of Publication:
United States
Language:
English