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Ions with low charges in the solar wind as measured by SWICS on board UlyssesWe present new data on rare ions in the solar wind. Using the Ulysses-SWICS instrument with its very low background we have searched for low-charge ions during a 6-d period of low-speed solar wind and established sensitive upper limits for many species. In the solar wind, we found He(1+)/He(2+) of less than 5 x 10 exp -4. This result and the charge state distributions of heavier elements indicate that all components of the investigated ion population went through a regular coronal expansion and experienced the typical electron temperatures of 1 to 2 million Kelvin. We argue that the virtual absence of low-charge ions demonstrates a very low level of nonsolar contamination in the source region of the solar wind sample we studied. Since this sample showed the FlP effect typical for low-speed solar wind, i.e., an enhancement in the abundances of elements with low first ionization potential, we conclude that this enhancement was caused by an ion-atom separation mechanism operating near the solar surface and not by foreign material in the corona.
Document ID
19930049627
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Geiss, J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Ogilvie, K. W.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Von Steiger, R.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Mall, U.
(Bern Univ. Switzerland)
Gloeckler, G.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Galvin, A. B.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Ipavich, F.
(Maryland Univ. College Park, United States)
Wilken, B.
(Max-Planck-Inst. fuer Aeronomie Katlenburg-Lindau, Germany)
Gliem, F.
(Braunschweig Univ. Germany)
Date Acquired
August 16, 2013
Publication Date
January 1, 1992
Publication Information
Publication: In: Solar Wind Seven; Proceedings of the 3rd COSPAR Colloquium, Goslar, Germany, Sept. 16-20, 1991 (A93-33554 13-92)
Publisher: Pergamon Press
Subject Category
Solar Physics
Accession Number
93A33624
Distribution Limits
Public
Copyright
Other

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