Cross-field transport of less than 1 MeV protons in energetic particle eventsA systematic analysis of hourly averaged low-energy anisotropy data (0.3-0.5 MeV) has been carried out with the JHU/APL detectors onboard the IMP-7 and 8 spacecraft from 1972-1975. The energetic particle events were divided into two major groups: flare-associated or nonimpulsive. Resolving the anistropy vectors into components parallel and perpendicular to the measured magnetic field leads directly to the following model-independent conclusions: (1) the average perpendicular anisotropy component is entirely accounted for in terms of the ExB drift, and hence transverse diffusion is negligible at these energies; application of the diffusion model to the nonimpulsive data set implies a ratio of the diffusion mean free paths parallel and perpendicular to the magnetic field much less than 0.051; (2) the parallel anisotropy component averages nearly to zero in the nonimpulsive data set, indicating virtually no net streaming along the field at 1 AU, averaged over all events.
Document ID
19810028057
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Zwickl, R. D. (Johns Hopkins Univ. Silver Spring, MD, United States)
Roelof, E. C. (Johns Hopkins Univ. Silver Spring, MD, United States)
Gold, R. E. (Johns Hopkins University Applied Physics Laboratory, Laurel, Md., United States)