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Mirror Instability in the Solar Wind: The Theory Revisited"Magnetic holes", localized depressions in the interplanetary magnetic field, have been identified in Ulysses data over a range of several AU and as far as 23 degrees south in latitude by Winterhalter et al., who concluded that these structures are most likely the remnants of structures caused by occasional mirror-mode instability in the solar wind. However, these authors, like a number of previous investigators, used the mirror stability criterion derived from the kinetic theory under very special assumptions. On the other hand, theoretical investigations using the fully self-consistent kinetic theory (Vlasov-Maxwell equations) have shown that the mirror stability criterion is more complicated when electrons and ions have different anisotropies, as is normally the case in the solar wind. Winterhalter et al used an instability criterion of the form R is greater than 1, where R is a function of the thermal anisotropy; the correct criterion (for bi-Maxwellian distributions) is R R is greater than 1 - x(exp 2), where x is a real quantity that depends on both the proton anisotropy and electron anisotropy. So nonzero x would modify the Winterhalter et al results in the direction of reinforcing their conclusions. We have revisited the instability criterion in its most general form, allowing for (a) non-Maxwellian velocity distributions, (b) multiple ion species, and (c) interparticle streaming. These results should give sound theoretical grounding for future observational studies related to the mirror instability, by Ulysses and other spacecraft.
Document ID
20020033162
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Barnes, A.
(NASA Ames Research Center Moffett Field, CA United States)
Date Acquired
August 20, 2013
Publication Date
January 1, 1995
Subject Category
Solar Physics
Meeting Information
Meeting: AGU Fall Meeting
Location: San Francisco, CA
Country: United States
Start Date: December 11, 1995
End Date: December 15, 1995
Sponsors: American Geophysical Union
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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