HR: 0800h
AN: SH51A-02    [Abstracts]
TI: Test-particle Orbit Simulations in Fields from a Realistic 3D MHD Simulation
AU: * Decker, R B
EM: robert.decker@jhuapl.edu
AF: Johns Hopkins Univ., Applied Physics Lab., 11100 Johns Hopkins Rd, Laurel, MD 20723- 6099, United States
AU: Opher, M
EM: physics.gmu.edu/~mopher
AF: George Mason University, 4400 University Drive, MSN 3F3, Fairfax, VA 22030-4444, United States
AU: Hill, M E
EM: Matt.Hill@jhuapl.edu
AF: Johns Hopkins Univ., Applied Physics Lab., 11100 Johns Hopkins Rd, Laurel, MD 20723- 6099, United States
AB: Models designed to explore the global structure of the heliosphere have become increasing sophisticated. Incentives to increase and to further explore the predictive capabilities of such models include the entry of the Voyager spacecraft into the foreshock region of the termination shock (TS), Voyager 1 in mid-2002 and Voyager 2 in late 2004, and the crossing of the TS and passage into the heliosheath (HSH) of Voyager 1 in 2004 day 351. Using the electric and magnetic fields generated by a MHD model of a 3D, asymmetric heliosphere [Opher et al., Ap. J. L., 640, 2006], we have developed full-particle and adiabatic-orbit codes to simulate the motion of test particles in the solar wind, TS, and HSH environments. The full-particle orbits are necessary to investigate energetic ion (e.g., anomalous and galactic cosmic ray) motion at the TS and within the heliospheric current sheet that is included in the MHD model. Adiabatic orbits are used to study particle motion in the much larger volume of the HSH where the non-homogeneous model fields produce complex guiding center motions, including mirroring in local field compressions. We will present results from these orbit computations, which are intended to provide an initial, albeit simplified, look at the propagation of high-energy charged particles, in the scatter-free limit, in the best model of the TS/HSH field configurations currently available. We will also display drift paths of high-energy ions in the HSH fields using the guiding center drift equations that are applicable in the limit of diffusive propagation.
DE: 2104 Cosmic rays
DE: 2114 Energetic particles (7514)
DE: 2124 Heliopause and solar wind termination
DE: 2139 Interplanetary shocks
DE: 7807 Charged particle motion and acceleration
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Joint Assembly