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Magnetic field power density spectra during 'scatter-free' solar particle eventsWe have examined interplanetary magnetic field power spectral density during four previously identified 3He-rich flare periods when the about 1 MeV nucleon-1 particles exhibited nearly scatter-free transport from the sun to 1 AU. Since the scattering mean free path A was large, it might be expected that interplanetary turbulence was low, yet the spectral density value was low only for one of the four periods. For the other three, however, the spectral index q of the power density spectrum was near 2.0, a value at which quasi-linear theories predict an increase in the scattering mean free path. Comparing the lambda values from the energetic particles with that computed from a recent quasi-linear theory which includes helicity and the propagation direction of waves, we find lambda(QLT)/lambda(SEP) = 0.08 +/- 0.03 for the four events. Thus, the theory fits the q-dependence of lambda; however, as found for previous quasi-linear theories, the absolute value is low.
Document ID
19930053822
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Tan, L. C. (NASA Headquarters Washington, DC United States)
Mason, G. M. (Maryland Univ. College Park, United States)
Date Acquired
August 16, 2013
Publication Date
May 20, 1993
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 409
Issue: 1
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: NAGW-1990
CONTRACT_GRANT: NSF ATM-90-23414
CONTRACT_GRANT: NAG5-728
Distribution Limits
Public
Copyright
Other