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Energetic oxygen and sulfur ions in the Jovian magnetosphereObservations of 1 to 20 MeV/nuc oxygen, sodium, and sulfur ions in the Jovian magnetosphere are reported. Measurements made by the cosmic ray subsystem on Voyager 1 and 2 were used to calculate abundances and energy spectra in the region from 5 to 20 Jovian radii. The phase space density of the oxygen ions calculated from the spectra has a positive radial gradient between 6 and 17 Jovian radii, indicating an inward diffusive flow. The diffusion coefficient upper limit at 9 Jovian radii is approximately 10 to the -5 power/s. This limit, combined with the analysis of Voyager plasma observations by Siscoe et al.1981, implies an upper limit to the mass loading rate near Io of approximately 10 to the 28th power ions/s. The energetic oxygen lifetime is within an order of magnitude of the strong pitch-angle diffusion lifetime in this region, with the largest total number of particles lost between 7.5 and 12.5 Jovian radii. It is shown that the losses are not due to geometric absorption by Io, absorption by dust grains, or energy loss in the plasma of the inner magnetosphere, and it is therefore postulated that the primary loss mechanism is pitch-angle scattering into the loss cone.
Document ID
19810025589
Acquisition Source
Legacy CDMS
Document Type
Thesis/Dissertation
Authors
Gehrels, N. (California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
September 4, 2013
Publication Date
January 1, 1981
Subject Category
Lunar And Planetary Exploration
Report/Patent Number
SRL-81-26
NASA-CR-164860
Accession Number
81N34132
Funding Number(s)
CONTRACT_GRANT: NAGW-200
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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