HR: 0800h
AN: SH51A-1194    [Abstracts]
TI: Shock Acceleration of Pickup Ions with a Field-Aligned Focused Transport Approach
AU: * le Roux, J A
EM: jakobus.leroux@ucr.edu
AF: University of California, 900 University Avenue, Riverside, CA 92521 United States
AU: Webb, G M
EM: gmwebb@ucr.edu
AF: University of California, 900 University Avenue, Riverside, CA 92521 United States
AB: Voyager 1 observations close to the termination shock show that ion distributions are highly anisotropic in the energy range of ~20 keV to ~20 MeV. These anisotropies, which are basically field-aligned, are too large for cosmic-ray diffusion theory to apply. Thus the formation of anomalous cosmic rays cannot be accurately modeled using standard cosmic-ray diffusion theory. To address this limitation, we are in the process of developing a model based on field-aligned focused transport and acceleration where there are no restrictions on particle pitch-angle anisotropy. As illustration of the feasibility of the model, we will show how a ring beam of interstellar pickup ions are accelerated to anomalous cosmic-ray energies at a strong shock as a function of upstream magnetic field obliquity. The role of magnetic mirroring or reflection of particles by the compression in the magnetic field across the shock and how this affects the slope of the accelerated spectrum at low energies will be investigated. Particle anisotropies at low energies will be discussed.
DE: 2104 Cosmic rays
DE: 2124 Heliopause and solar wind termination
DE: 2152 Pickup ions
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005