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Measurements of geomagnetically trapped alpha particles, 1968-1970. I - Quiet time distributionsResults of observations of geomagnetically trapped alpha particles over the energy range from 1.18 to 8 MeV performed with the aid of the Injun 5 polar-orbiting satellite during the period from September 1968 to May 1970. Following a presentation of a time history covering this entire period, a detailed analysis is made of the magnetically quiet period from Feb. 11 to 28, 1970. During this period the alpha particle fluxes and the intensity ratio of alpha particles to protons attained their lowest values in approximately 20 months; the alpha particle intensity versus L profile was most similar to the proton profile at the same energy per nucleon interval; the intensity ratio was nearly constant as a function of L in the same energy per nucleon representation, but rose sharply with L when computed in the same total energy interval; the variation of alpha particle intensity with B suggested a steep angular distribution at small equatorial pitch angles, while the intensity ratio showed little dependence on B; and the alpha particle spectral parameter showed a markedly different dependence on L from the equivalent one for protons.
Document ID
19740029879
Document Type
Reprint (Version printed in journal)
Authors
Krimigis, S. M.
Verzariu, P. (Johns Hopkins University Silver Spring, Md., United States)
Date Acquired
August 7, 2013
Publication Date
November 1, 1973
Publication Information
Publication: Journal of Geophysical Research
Volume: 78
Subject Category
GEOPHYSICS
Funding Number(s)
CONTRACT_GRANT: NSF GA-30841
CONTRACT_GRANT: NAS1-2973
Distribution Limits
Public
Copyright
Other