HR: 0800h
AN: SH51A-04 [Abstracts]
TI: The Composition of Energetic Particles in the Termination Foreshock and Heliosheath
AU: * Hill, M E
EM: matt.hill@jhuapl.edu
AF: Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723-6099, United
States
AU: Decker, R B
AF: Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723-6099, United
States
AU: Krimigis, S M
AF: Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723-6099, United
States
AU: Krimigis, S M
AF: Academy of Athens, Academy of Athens, Athens, Greece
AB:
Comparisons between the energetic particle measurements made with the Low Energy Charged Particle
instrument on Voyager 1 in the termination foreshock (TFS) and the heliosheath (HS) have revealed some key
features, using the observational tools of intensity, anisotropy, and spectral measurements. The shape and
temporal evolution of ion spectra in both the TFS and the HS are organized by total kinetic energy. This total
energy dependence is a robust feature that should be predicted by models and theories. In the TFS the
anisotropies are organized by energy per nucleon but the spectra are organized by total kinetic energy. In the HS
there is a period with anisotropy and spectra organized by total energy. Possibly this is evidence for two different
transport regimes. There is at least one component of the spectra (dubbed "third source" particles) from
~1-100 MeV that exhibits different time profiles, spectral shape, and anisotropy from either the TFS particles
or anomalous cosmic rays. In addition to the intensities, anisotropies, and spectral variations there remains an
important tool to try to probe the energetic particle phenomena near the termination shock. This tool is elemental
composition. We will report on the composition of energetic ions in the different regions of the TFS observed by
Voyager 1 and 2, and in the HS observed by Voyager 1. In particular we will examine the comparative composition
in these regions and relate this to previously measured pickup ions and anomalous cosmic ray composition.
DE: 2104 Cosmic rays
DE: 2114 Energetic particles (7514)
DE: 2124 Heliopause and solar wind termination
DE: 7859 Transport processes
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Joint Assembly