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Electron temperature and density relationships in coronal mass ejectionsWe examine 10 coronal mass ejections from the in-ecliptic portion of the Ulysses mission. Five of these CMEs are magnetic clouds. In each case we observe an inverse relationship between electron temperature and density. For protons this relationship is less clear. Earlier work has shown a similar inverse relationship for electrons inside magnetic clouds and interpreted it to mean that the polytropic index governing the expansion of electrons is less than unity. This requires electrons to be heated as the CME expands. We offer an alternative view that the inverse relationship between electron temperature and density is caused by more rapid cooling of the denser plasma through collisions. More rapid cooling of denser plasma has been shown for 1 AU measurements in the solar wind. As evidence for this hypothesis we show that the denser plasma inside the CMEs tends to be more isotropic indicating a different history of collisions for the dense plasma. Thus, although the electron temperature inside CMEs consistently shows an inverse correlation with the density, this is not an indication of the polytropic index of the plasma but instead supports the idea of collisional modification of the electrons during their transit from the sun.
Document ID
19960021487
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
Authors
Hammond, C. M.
(Los Alamos National Lab. NM United States)
Phillips, J. L.
(Los Alamos National Lab. NM United States)
Balogh, A.
(Imperial Coll. of Science and Technology London, United Kingdom)
Date Acquired
August 17, 2013
Publication Date
June 30, 1995
Publication Information
Publication: International Solar Wind 8 Conference
Subject Category
Solar Physics
Accession Number
96N24883
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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