HR: 1340h
AN: SH44A-1719    [Abstracts]
TI: Fast Reconnection in Electron-Positron Plasmas via Turbulent Outflow Jets
AU: * Swisdak, M
EM: swisdak@umd.edu
AF: University of Maryland, IREAP, College Park, MD 20742, United States
AU: Liu, Y
EM: yhliu10@umd.edu
AF: University of Maryland, IREAP, College Park, MD 20742, United States
AU: Drake, J
EM: drake@umd.edu
AF: University of Maryland, IREAP, College Park, MD 20742, United States
AB: Numerical simulations of reconnection in electron-positron (pair) plasmas provide an interesting test of current theories of whistler-mediated Hall reconnection. Because of the system's mass symmetry the Hall term vanishes from the generalized Ohm's law, suggesting that perhaps pair reconnection is slow, as in the classic Sweet-Parker picture. But, as has already been documented, pair reconnection is, in fact, fast. We present large particle-in-cell simulations of pair reconnection confirming that the reconnection rate remains constant and fast even as the system size changes by almost an order of magnitude. The current layer extends to almost the system size in the smallest boxes but stops growing as the box size increases. For the largest systems we identify a Weibel-like temperature anisotropy instability in the outflow from the X-line that causes the current layer to broaden and permits fast reconnection. We discuss the implications of this instability, in particular whether it allows pair reconnection to be fast in all parameter regimes.
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 7526 Magnetic reconnection (2723, 7835)
DE: 7829 Kinetic waves and instabilities
DE: 7835 Magnetic reconnection (2723, 7526)
DE: 7863 Turbulence (4490)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting