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Found 2 entries in the Bibliography.
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1972 |
Inner-Zone Energetic-Electron Repopulation by Radial Diffusion A quantitative study of the intrusion of natural electrons into the inner radiation zone during and after the geomagnetic storm of September 2, 1966, shows that the transport is consistent with a radial-diffusion mechanism in which the first two invariants are conserved. Except for the 3-day period of the storm main phase when data were missing, the radial-diffusion coefficient is D = 2.7 \texttimes 10-5 L7.9 μ-0.5 day-1 in the range 1.7 <= L <= 2.6 and 13.3 <= μ <= 27.4 Mev gauss-1. This value could be produced by variation of a large-scale electric field across the magnetosphere having an amplitude of 0.28 mv / m and a period of 1600 sec. Electric fields having approximately these characteristics have been inferred from previous observations of the motion of whistler ducts within the plasmapause. If fields of this amplitude and period exist throughout the magnetosphere, the radial diffusion of all geomagnetically trapped particles except the high-energy inner-zone protons is strongly influenced by electric-field variations. A comprehensive review of previously reported radial-diffusion coefficients shows reasonable agreement for L less than about 3.0, but serious discrepancies among reported values exist for determinations made in the outer zone. These discrepancies cannot be explained by the simple theory of radial diffusion due to variation of large-scale electric or magnetic fields. Tomassian, Albert; Farley, Thomas; Vampola, Alfred; Published by: Journal of Geophysical Research Published on: 07/1972 YEAR: 1972   DOI: 10.1029/JA077i019p03441 |
1969 |
Radial Diffusion of Starfish Electrons A study of the change in electron intensities in the Starfish electron belt from January 1, 1963, to November 3, 1965, indicates that radial diffusion, both inward and outward from L of 1.40, was a significant loss mechanism for these electrons during this period. For L values of 1.20 and below, the indicated steepening of the pitch-angle distributions during this period has been interpreted as the result of a radial diffusion source for each L shell concentrated near the geomagnetic equator. Since pitch-angle diffusion lifetimes are not well known for 1.20 < L < 1.65, a definitive radial diffusion coefficient cannot be computed from these data. A maximum reasonable diffusion coefficient (mean square displacement per unit time) computed for this range of L for this period has a minimum at L of 1.31, and a value of 4.4 \texttimes 10-5 RE\texttwosuperior/day at that point. This maximum coefficient, representing an average over a 3-year period, is more than an order of magnitude too small to account for the apparent radial diffusion of natural electrons into this region that took place in September 1966. The results are, however, consistent with population of the inner zone by radial electron diffusion occurring during relatively short periods during which the diffusion coefficient is enhanced by two or three orders of magnitude. Published by: Journal of Geophysical Research Published on: 07/1969 YEAR: 1969   DOI: 10.1029/JA074i014p03591 |
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