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Mirroring within the Fokker-Planck formulation of cosmic ray pitch angle scattering in homogeneous magnetic turbulenceThe Fokker-Planck coefficient for pitch angle scattering, appropriate for cosmic rays in homogeneous, stationary, magnetic turbulence, is computed from first principles. No assumptions are made concerning any special statistical symmetries the random field may have. This result can be used to compute the parallel diffusion coefficient for high energy cosmic rays moving in strong turbulence, or low energy cosmic rays moving in weak turbulence. Becuase of the generality of the magnetic turbulence which is allowed in this calculation, special interplanetary magnetic field features such as discontinuities, or particular wave modes, can be included rigorously. The reduction of this results to previously available expressions for the pitch angle scattering coefficient in random field models with special symmetries is discussed. The general existance of a Dirac delta function in the pitch angle scattering coefficient is demonstrated. It is proved that this delta function is the Fokker-Planck prediction for pitch angle scattering due to mirroring in the magnetic field.
Document ID
19740015243
Acquisition Source
Legacy CDMS
Document Type
Technical Memorandum (TM)
Authors
Goldstein, M. L.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Klimas, A. J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Sandri, G.
(Aeronautical Res. Assoc. of Princeton, Inc.)
Date Acquired
September 3, 2013
Publication Date
May 1, 1974
Subject Category
Space Radiation
Report/Patent Number
X-692-74-117
NASA-TM-X-70645
Accession Number
74N23356
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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