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Transport, charge exchange and loss of energetic heavy ions in the earth's radiation belts - Applicability and limitations of theoryComputer simulations of processes which control the relative abundances of ions in the trapping regions of geospace are compared with observations from discriminating ion detectors. Energy losses due to Coulomb collisions between ions and exospheric neutrals are considered, along with charge exchange losses and internal charge exchanges. The time evolution of energetic ion fluxes of equatorially mirroring ions under radial diffusion is modelled to include geomagnetic and geoelectric fluctutations. Limits to the validity of diffusion transport theory are discussed, and the simulation is noted to contain provisions for six ionic charge states and the source effect on the radiation belt oxygen ion distributions. Comparisons are made with ion flux data gathered on Explorer 45 and ISEE-1 spacecraft and results indicate that internal charge exchanges cause the radiation belt ion charge state to be independent of source charge rate characteristics, and relative charge state distribution is independent of the radially diffusive transport rate below the charge state redistribution zone.
Document ID
19820032928
Document Type
Reprint (Version printed in journal)
Authors
Spjeldvik, W. N. (Cooperative Institute for Research in Environmental Sciences Boulder, CO, United States)
Date Acquired
August 10, 2013
Publication Date
November 1, 1981
Subject Category
SPACE RADIATION
Funding Number(s)
CONTRACT_GRANT: NASA ORDER S-50897-G
Distribution Limits
Public
Copyright
Other