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Proton and electron mean free paths: The Palmer consensus revisitedWe present experimental and theoretical evidence suggesting that the mean free path of cosmic-ray electrons and protons may be fundamentally different at low to intermediate (less than 50 MV) rigidities. The experimental evidence is from Helios observations of solar energetic particles, which show that the mean free path of 1.4 MV electrons is often similar to that of 187 MV protons, even though proton mean free paths continue to decrease comparatively rapidly with decreasing rigidty down to the lowest channels (about 100 MV) observed. The theoretical evidence is from computations of particle scattering in dynamical magnetic turbulence, which predict that electrons will have a larger mean free path than protons of the same rigidity. In the light of these new results, 'consensus' ideas about cosmic-ray mean free paths may require drastic revision.
Document ID
19950035616
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Bieber, John W.
(Univ. of Delaware, Newark, DE United States)
Matthaeus, William H.
(Univ. of Delaware, Newark, DE United States)
Smith, Charles W.
(Univ. of Delaware, Newark, DE United States)
Wanner, Wolfgang
(Universitat Kiel Kiel, Germany)
Kallenrode, May-Britt
(Universitat Kiel Kiel, Germany)
Wibberenz, Gerd
(Universitat Kiel Kiel, Germany)
Date Acquired
August 16, 2013
Publication Date
January 1, 1994
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 420
Issue: 1
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
95A67215
Funding Number(s)
CONTRACT_GRANT: NSF ATM-89-13627
CONTRACT_GRANT: NSF ATM-90-14806
CONTRACT_GRANT: NAGW-1637
Distribution Limits
Public
Copyright
Other

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