HR: 1340h
AN: SM53B-1280    [Abstracts]
TI: Are Electron Distributions Associated with Reconnection Electrostatically Unstable and do they lead to Electron Holes?
AU: * Goldman, M V
EM: goldman@spot.colorado.edu
AF: University of Colorado, Center for Integrated Plasma Studies, 390UCB, Boulder, CO 80309, United States
AU: Newman, D L
EM: David.Newman@colorado.edu
AF: University of Colorado, Center for Integrated Plasma Studies, 390UCB, Boulder, CO 80309, United States
AU: Pritchett, P
EM: pritchett@physics.ucla.edu
AF: UCLA, Physics & Astronomy, Box 951547, Los Angeles, CA 90095-1547, United States
AB: Model electron distributions arising in the late stages of 2-D PIC simulations¹ of magnetic reconnection with a guide field are used to initialize 1-D and 2-D electrostatic Vlasov simulations, which are oriented to include the direction parallel to the (local) magnetic field. Transient electron holes are found to develop near the separatrix through a electron-ion (e.g., Buneman) instability. Restriction of the destabilizing current to a narrow sheet perpendicular to \mathbf{B} reduces the Buneman growth rate, possibly leading to more stable holes. Near the X-point, electron-electron two-stream instabilities can produce quasi-stable electron holes. These first-generation holes can modify the electron-ion interaction resulting in a second generation of holes, with a variety of subsequent hole-hole interactions that depend on the details of the initial distributions. When the holes are shallow and well-separated they can be analyzed using stationary solutions² based on the condition eφ/T_e \ll 1. ^*Research supported by DOE, NASA, and NSF. ¹P.~L.~Pritchett, Phys.~Plasmas, 12, 062301 (2005). ²M.~V.~Goldman, D.~L.~Newman, and A.~Mangeney, Phys.~Rev.~Lett., in press, (2007).
DE: 7835 Magnetic reconnection (2723, 7526)
DE: 7839 Nonlinear phenomena (4400, 6944)
DE: 7845 Particle acceleration
DE: 7863 Turbulence (4490)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting