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Measurement of the electron beam mode in earth's foreshockHigh frequency electric field measurements from the AMPTE IRM plasma wave receiver are used to identify three simultaneously excited electrostatic wave modes in the earth's foreshock region: the electron beam mode, the Langmuir mode, and the ion acoustic mode. A technique is developed which allows the rest frame frequecy and wave number of the electron beam waves to be determined. It is shown that the experimentally determined rest frame frequency and wave number agree well with the most unstable frequency and wave number predicted by linear homogeneous Vlasov theory for a plasma with Maxwellian background electrons and a Lorentzian electron beam. From a comparison of the experimentally determined and theoretical values, approximate limits are put on the electron foreshock beam temperatures. A possible generation mechanism for ion acoustic waves involving mode coupling between the electron beam and Langmuir modes is also discussed.
Document ID
19900043505
Document Type
Reprint (Version printed in journal)
Authors
Onsager, T. G. (Washington Univ. Seattle, WA, United States)
Holzworth, R. H. (Washington, University Seattle, United States)
Date Acquired
August 14, 2013
Publication Date
April 1, 1990
Publication Information
Publication: Journal of Geophysical Research
Volume: 95
ISSN: 0148-0227
Subject Category
GEOPHYSICS
Funding Number(s)
CONTRACT_GRANT: N00014-84-K-0160
CONTRACT_GRANT: NAGW-1218
Distribution Limits
Public
Copyright
Other