HR: 0800h
AN: SM51B-04 [Abstracts]
TI: Magnetic Turbulence in Colliding Laser-Produced Plasmas
AU: * Collette, A
EM: collette@physics.ucla.edu
AF: University of California, Los Angeles, 1000 Veteran Ave, Rm 15-70, Los Angeles, CA
90095, United States
AU: Gekelman, W
EM: gekelman@physics.ucla.edu
AF: University of California, Los Angeles, 1000 Veteran Ave, Rm 15-70, Los Angeles, CA
90095, United States
AU: Vincena, S
EM: vincena@physics.ucla.edu
AF: University of California, Los Angeles, 1000 Veteran Ave, Rm 15-70, Los Angeles, CA
90095, United States
AB:
The expansion and interaction of dense plasmas in the presence of a magnetized background plasma is
important in many astrophysical processes, among them coronal mass ejections and the many examples of
plasma jets from astrophotography. Turbulence is expected to be present in many such configurations. We
describe a series of experiments which involve the collision of two dense (initially, n > 1015cm-3)
laser-produced plasmas within an ambient, highly magnetized background plasma. The laser-produced
plasmas form diamagnetic cavities in which a large percentage of the background magnetic field (600G) has
been expelled. First-stage observations of these structures have been completed using a fast (3ns exposure)
camera. The photographs indicate complicated structure at late times, in addition to coherent corrugated
structures on the bubble surfaces. The data hint at the presence of turbulence in the interaction. The second
stage of observation will consist of direct investigation of the magnetic field using probes. A novel diagnostic
system composed of small (300-500 micron) 3-axis differential magnetic field probes in conjunction with a
ceramic motor system capable of extremely fine (sub-micron) positioning accuracy is currently under
development. An ensemble of magnetic field data from fixed and movable probes makes possible the
calculation of the cross-spectral function. Initial data from photography and a prototype probe will be presented.
DE: 7829 Kinetic waves and instabilities
DE: 7831 Laboratory studies and experimental techniques
DE: 7836 MHD waves and instabilities (2149, 2752, 6050)
DE: 7863 Turbulence (4490)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly