B.T. Tsurutani1,3, L.D. Zhang1, Glenn M. Mason2,4, Gurbax Lakhina1, Tohru Hada5, John K. Arballo1, Ronald D. Zwickl3 1 Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, California 91109 2 Department of Physics, University of Maryland, College Park, Maryland 20742 3 National Oceanic and Atmospheric Administration, Space Environment Laboratory, Code R/E/SE, Boulder, Colorado 80303 4 Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 25742 5 ESST Kyushu University, Kasuga 816-8580, Japan
ISEE-3 energetic particles and MHD waves are studied to investigate
particle propagation and scattering between the source near the Sun and
the Earth (1 AU). For 3He rich events, simultaneous
interplanetary magnetic spectra are measured. The interplanetary
turbulence through which the particles have traversed is found to be
fairly low. This can be interpreted as indicating that either low
turbulence fields are necessary for the particles to propagate long
(~1.3 AU) distances, or that the fields above active regions producing
3He events have a lack of waves/turbulence. If the former
is the case, there may be many 3He events at the sun that
are not detected at 1 AU.
The largest solar particle events are
analyzed to investigate the possibilities of local wave generation at 1
AU. No evidence for wave instability is found at either the leading
edge or at the point of peak flux. Our results indicate that
interplanetary solar wind "fossil" waves are the important scatterers
for particles coming from the Sun to 1 AU, and it is the quiet to
intermediate level of IMF activity that are associated with the
3He scatter-free events.
Lastly we intercompare the particle mean free paths calculated from
resonant wave-particle interactions and from
those derived from 3He++ intensity and anisotropy
time profiles
. By including measured wave polarization and wave
k directions, we decrease the previously noted discrepancy
between
and
by a factor of ~ 2.
We note that
is determined by the process of pitch angle scattering
from ~ 0° to ~ 180°, while
by that
from ~ 0° to ~ < 90°. But the scattering across 90°
pitch angle is a different process.
Therefore the remaining discrepancy between
and
may lie
in the fact that diffusion across 90° pitch angle is much slower
than resonant scattering near 0° and 180° pitch angle.