EarthRef.org Reference Database (ERR)
Development and Maintenance by the EarthRef.org Database Team

Detailed Reference Information
Gekelman et al. 2003
Gekelman, W., Van Zeeland, M., Vincena, S. and Pribyl, P. (2003). Laboratory experiments on Alfvén waves caused by rapidly expanding plasmas and their relationship to space phenomena. Journal of Geophysical Research 108. doi: 10.1029/2002JA009741. issn: 0148-0227.

There are many situations which naturally occur in space (coronal mass ejections, supernovas) or are man-made (upper atmospheric detonations) in which a dense plasma expands into a background magnetized plasma that can support Alfv¿n waves. The Large Plasma Device (LAPD) at UCLA is a machine in which Alfv¿n wave propagation in homogeneous and inhomogeneous plasmas has been studied. A new class of experiments which involve the expansion of a dense (initially nlaser-produced/nbackground ≫ 1) laser-produced plasma into an ambient highly magnetized plasma capable of supporting Alfv¿n waves will be presented. The 150 MW laser is pulsed at the same 1 Hz repetition rate as the plasma in a highly reproducible experiment. The laser beam impacts a solid target such that the initial plasma burst is directed across the ambient magnetic field. The interaction results in the production of intense shear and compressional Alfv¿n waves, as well as large density perturbations. The waves propagate away from the target and are observed to become plasma column resonances. The magnetic fields of the waves are measured with a 3-axis inductive probe. Spatial patterns of the magnetic fields associated with the waves and density perturbations are acquired at over 10,000 spatial locations and as a function of time. Measurements are used to estimate the coupling efficiency of the laser energy and kinetic energy of the dense plasma into wave energy. The shear wave generation mechanism is due to field-aligned return currents, which replace fast electrons escaping the initial blast.

BACKGROUND DATA FILES

Abstract

Keywords
Space Plasma Physics, Laboratory studies, Solar Physics, Astrophysics, and Astronomy, Coronal mass ejections, Space Plasma Physics, Waves and instabilities, Interplanetary Physics, Ejecta, driver gases, and magnetic clouds, Solar Physics, Astrophysics, and Astronomy, Magnetic fields
Journal
Journal of Geophysical Research
http://www.agu.org/journals/jb/
Publisher
American Geophysical Union
2000 Florida Avenue N.W.
Washington, D.C. 20009-1277
USA
1-202-462-6900
1-202-328-0566
service@agu.org
Click to clear formClick to return to previous pageClick to submit