HR: 0800h
AN: SM51B-02    [Abstracts]
TI: Space-plasma campaign on UCLA's Large Plasma Device (LAPD)
AU: * Koepke, M E
EM: mkoepke@wvu.edu
AF: West Virginia Univ., Physics Dept., Morgantown, WV 26506-6325, United States
AU: Finnegan, S M
EM: sfinnega@mix.wvu.edu
AF: West Virginia Univ., Physics Dept., Morgantown, WV 26506-6325, United States
AU: Knudsen, D J
EM: knudsen@phys.ucalgary.edu
AF: Univ. of Calgary, Dept. of Physics and Astronomy, Calgary, ALB T2N 1N4, Canada
AU: Vincena, S
EM: vincena@phys.ucla.edu
AF: Univ. of California at Los Angeles, Dept. of Physics and Astronomy, Los Angeles, CA 95095, United States
AB: Knudsen [JGR, 1996] describes a potential role for stationary Alfvén (StA) waves in auroral arcs' frequency dependence. Magnetized plasmas are predicted to support electromagnetic perturbations that are static in a fixed frame if there is uniform background plasma convection. These stationary waves should not be confused with standing waves that oscillate in time with a fixed, spatially varying envelope. Stationary waves have no time variation in the fixed frame. In the drifting frame, there is an apparent time dependence as plasma convects past fixed electromagnetic structures. We describe early results from an experimental campaign to reproduce in the lab the basic conditions necessary for the creation of StA waves, namely quasi-steady-state convection across magnetic field-aligned current channels. We show that an off-axis, fixed channel of electron current (and depleted density) is created in the Large Plasma Device Upgrade (LAPD) at UCLA, using a small, heated, oxide-coated electrode at one plasma-column end and we show that the larger plasma column rotates about its cylindrical axis from a radial electric field imposed by a special termination electrode on the same end. Initial experimentation with plasma-rotation-inducing termination electrodes began in May 2006 in the West Virginia Q Machine, leading to two designs that, in January 2007, were tested in LAPD. The radial profile of azimuthal velocity was consistent with predictions of rigid-body rotation. Current-channel experiments in LAPD, in August 2006, showed that inertial Alfvén waves could be concentrated in an off-axis channel of electron current and depleted plasma density. These experimental results will be presented and discussed. This research is supported by DOE and NSF.
DE: 7829 Kinetic waves and instabilities
DE: 7831 Laboratory studies and experimental techniques
DE: 7846 Plasma energization
DE: 7867 Wave/particle interactions (2483, 6984)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly