HR: 1330h
AN: SM23B-05    [Abstracts]
TI: Sheared Buneman Instabilities in Current-Driven Plasmas
AU: * Goldman, M V
EM: goldman@spot.colorado.edu
AF: University of Colorado at Boulder, Center for Integrated Plasma Studies, 390-UCB, Boulder, CO 80309-0390 United States
AU: Newman, D L
EM: David.Newman@colorado.edu
AF: University of Colorado at Boulder, Center for Integrated Plasma Studies, 390-UCB, Boulder, CO 80309-0390 United States
AU: Sen, N
EM: Naresh.Sen@colorado.edu
AF: University of Colorado at Boulder, Center for Integrated Plasma Studies, 390-UCB, Boulder, CO 80309-0390 United States
AB: Simulation studies of magnetic reconnection in strongly magnetized plasmas¹ have indicated that electron phase-space holes evolve out of current-driven Buneman instabilities and that these holes play an important role in supplying the needed dissipation in the reconnection process by acting as electron scattering centers. Drake and collaborators have shown in simulations that the evolution of electron holes is mediated by lower hybrid waves. We have shown independently, via 2-D simulations of the evolution of Buneman instabilities, that electron phase space holes evolve and interact with lower hybrid waves in a manner similar to that seen in the reconnection simulations² Perpendicular shear in the parallel velocity and the current will be present near the edges and elsewhere in realistic current sheets associated with magnetic reconnection. We have studied the effects of such shear on the nature and evolution of Buneman instabilities and the resulting electron phase space holes. Both linear theory and 2-D Vlasov simulations are employed. It is shown that even a small amount of velocity shear can have a large effect on the nonlinear evolution of holes and lower hybrid waves. ¹Drake, J. F., M. Swisdak, C. Cattell, M. A. Shay, B. N. Rogers, and A.~Zeiler, Formation of Electron Holes and Particle Energization During Magnetic Reconnection, Science, 299, (2003). ²Martin V. Goldman, D. L. Newman, A. Mangeney, F. Califano, Theory and Simulation of Sheared Electron Beam Instabilities in Strongly Magnetized Plasmas, COSPAR04-A-02395; D3.5-0015-04, 35th COSPAR Scientific Assembly Paris, France, 18 - 25 July 2004. This research was supported by DOE, NSF and NASA.
DE: 2772 Plasma waves and instabilities
DE: 7815 Electrostatic structures
DE: 7835 Magnetic reconnection
DE: 7839 Nonlinear phenomena
DE: 7843 Numerical simulation studies
SC: SPA-Magnetospheric Physics [SM]
MN: 2005 Joint Assembly