HR: 0830h
AN: SH31A-1090    [PDF]
TI: Thin anisotropic current sheets: Equilibrium theory and simulations of current -driven instabilities
AU: * Sitnov, M I
EM: sitnov@glue.umd.edu
AF: Institute for Research in Electronics and Applied Physics, University of Maryland, IREAP, UMCP, College Park, MD 20742 United States
AU: Swisdak, M
EM: swisdak@glue.umd.edu
AF: Institute for Research in Electronics and Applied Physics, University of Maryland, IREAP, UMCP, College Park, MD 20742 United States
AU: Drake, J F
EM: drake@glue.umd.edu
AF: Institute for Research in Electronics and Applied Physics, University of Maryland, IREAP, UMCP, College Park, MD 20742 United States
AU: Guzdar, P N
EM: guzdar@glue.umd.edu
AF: Institute for Research in Electronics and Applied Physics, University of Maryland, IREAP, UMCP, College Park, MD 20742 United States
AU: Rogers, B N
EM: barrett.rogers@dartmouth.edu
AF: Department of Physics and Astronomy, Dartmouth College, HB 6127, Wilder Buiding, Hanover, NH 03755 United States
AB: Concentration of the current in thin sheets forms a free energy source for instabilities of the plasma waves, which do not change the initial magnetic topology as they propagate mainly in the current direction. However, these current-driven instabilities may be an effective mechanism of collisionless dissipation and thus promote the reconnection process. Until recently both the linear stability analysis and simulations of current-driven instabilities were limited to the single class of initial equilibria known as Harris current sheets [Harris, 1962]. This limitation did not allow, in particular, the modeling of the sheets with counter-streaming flows of ions, which are typical for the outflow region of the reconnection pattern in the deHoffman-Teller frame (hereafter outflow sheets) [e.g., Yamada et al., 2000; Hsu et al., 2001], and the thin current sheets with two-humped profile of the current density (bifurcated sheets) found in multi-spacecraft observations of the current sheet of Earth's magnetotail [Nakamura et al., 2002; Runov et al., 2003; Sergeev et al., 2003]. Recently the Harris current sheet model was generalized to account for the aforementioned features of the thin current sheets [Sitnov et al., 2003] and then it was included in the massively parallel particle code P3D [Zeiler et al., 2001]. We report the first results of studies of the current-driven instabilities using that modified particle code. We compare in particular the stability picture in thin Harris sheets and similar pictures in the cases of outflow and bifurcated current sheets.
DE: 2744 Magnetotail
DE: 7827 Kinetic and MHD theory
DE: 7835 Magnetic reconnection
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting