Observation of laser-induced anisotropic changes in the frequency and damping of ion acoustic waves in a laser plasma

Journal Article · Wed Mar 01 04:00:00 EST 1989 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.39.2549· OSTI ID:6201908

Bernard, J E; Baldis, H A; Villeneuve, D M; Langdon, A B; Rozmus, W

Temporally and spectrally resolved large-angle Thomson scattering was used to study the frequency and damping of short-wavelength (klambda/sub D//sub e/approx.1) ion acoustic fluctuations in a plasma in the presence of a high-frequency (..omega../sub 0/>..omega../sub pe/) laser beam. At high laser intensities (v/sub osc//v/sub e/>1), the frequency of the ion acoustic waves which propagated parallel to the electric field of the laser (i.e., parallel to the electron quiver velocity) was observed to be larger than the frequency of the waves which propagated in the perpendicular direction. An increase in the fluctuation amplitude for those waves that propagated parallel to the electric field was observed to be coincident with the shift in the ion acoustic frequency. Both the frequency shift and the increase in the fluctuation amplitude can be explained in terms of the off-resonance ion acoustic decay and the off-resonance oscillating two-stream instabilities. The experimental results are in good agreement with the predictions of theory.

• Research Organization: Division of Physics, National Research Council of Canada, Ottawa, Ontario, Canada K1Achemically bond0R6
• OSTI ID: 6201908
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 39:5; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
ANISOTROPY
DAMPING
ELECTROMAGNETIC RADIATION
INELASTIC SCATTERING
INSTABILITY
ION ACOUSTIC WAVES
ION WAVES
LASER RADIATION
MODULATION
PLASMA
PLASMA INSTABILITY
PLASMA WAVES
RADIATIONS
SCATTERING
SPECTRAL SHIFT
THOMSON SCATTERING