HR: 1340h
AN: SH44A-1715    [Abstracts]
TI: Fully Kinetic 3D Simulations of Collisionless Reconnection in Large-Scale Pair Plasmas
AU: * Yin, L
EM: lyin@lanl.gov
AF: Los Alamos National Laboratory, MS-F699, Los Alamos, NM 87545, United States
AU: Daughton, W
AF: Los Alamos National Laboratory, MS-F699, Los Alamos, NM 87545, United States
AU: Karimabadi, H
AF: University of California, San Diego, Dept. Electrical and Computer Engineering, La Jolla, CA 92093, United States
AU: Albright, B J
AF: Los Alamos National Laboratory, MS-F699, Los Alamos, NM 87545, United States
AU: Bowers, K J
AF: Los Alamos National Laboratory, MS-F699, Los Alamos, NM 87545, United States
AU: Margulies, J
AF: Los Alamos National Laboratory, MS-F699, Los Alamos, NM 87545, United States
AB: Fully kinetic simulation offers a first principles approach to the understanding of the key physics of magnetic reconnection in planetary magnetospheres and solar flares. However, the large separation between electron and ion spatial and temporal scales has severally limited these computational studies in 3D at large scales that are relevant to macroscopic physical systems. In contrast, kinetic simulation of reconnection in an electron-positron plasma is feasible in 3D at large scales. Reconnection in pair plasma is relevant to the understanding of several astrophysical problems, such as jets in active galactic nuclei, pulsar winds, and gamma-ray bursts. Furthermore, this limit provides useful insight into the dynamics of large-scale 3D reconnection, including role of the kink mode, in hydrogen plasmas. In this work, reconnection in pair plasma in large-scale 3D systems is examined using the highly optimized PIC code VPIC developed at LANL. Both the anti-parallel limit and the influence of the guide field is investigated. It is found that 3D reconnection involves initial growth of tearing islands and island coalescence to large scales followed by outward expansion of the diffusion region and repeated formations of secondary islands, consistent with results from recent 2D simulations [Daughton and Karimabadi, Phys. Plasmas 14, 072303, 2007]. However, from linear Vlasov theory, the unstable eigenmodes in a pair plasma in 3D also include the drift-kink mode in addition to the tearing mode. We will discuss how the reconnection dynamics is influenced by the nonlinear interaction of these modes with the formation of complicated 3D structures.
DE: 7526 Magnetic reconnection (2723, 7835)
DE: 7835 Magnetic reconnection (2723, 7526)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting