Raman up-scattering in long-scale-length, laser-produced plasmas

Journal Article · Fri Feb 01 00:00:00 EST 1991 · Physics of Fluids B; (USA)

DOI:https://doi.org/10.1063/1.859886· OSTI ID:6251872

Batha, S H; Meyerhofer, D D; Simon, A ^[1]; Drake, R P ^[2]

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1. Department of Mechanical Engineering and Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, NY (USA)
2. Plasma Physics Research Institute, University of California and Lawrence Livermore National Laboratory, Livermore, CA (USA) Department of Applied Science, University of California Davis, Davis, CA (USA)

Frequency up-shifted light, produced by the interaction of a 351 nm laser with a plasma large enough to produce efficient down-shifted Raman backscattering, was measured. The plasma was created using low-intensity, 351 nm laser beams striking a 15 {mu}m thick CH foil. During the period of interest, the electron temperature was estimated to be 1 keV, the peak density to be 0.15 of the critical density, and the plasma scale length to be 1500 {mu}m at one-tenth critical density. The most straightforward explanation of the up-shifted light was found to be scattering from externally enhanced plasma waves. Scattering from a plasma mode created by coupling a large ion wave to a stimulated-Raman-scattering-produced plasma wave is also possible. Collisional damping precludes either scattering from a reflected electron-plasma wave produced by SRS or scattering from a plasma wave resulting from the onset of the Langmuir decay instability.

• DOE Contract Number: FC03-85DP40200; W-7405-ENG-48
• OSTI ID: 6251872
• Journal Information: Physics of Fluids B; (USA), Vol. 3:2; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
LASER RADIATION
HARMONICS
LASER-PRODUCED PLASMA
RAMAN EFFECT
COHERENT SCATTERING
COLLISIONAL PLASMA
COUPLING
DAMPING
ELECTRON PLASMA WAVES
ELECTRON TEMPERATURE
FOILS
HYDROCARBONS
ION WAVES
NEAR ULTRAVIOLET RADIATION
THICKNESS
DIMENSIONS
ELECTROMAGNETIC RADIATION
ORGANIC COMPOUNDS
OSCILLATIONS
PLASMA
PLASMA WAVES
RADIATIONS
SCATTERING
ULTRAVIOLET RADIATION
700108* - Fusion Energy- Plasma Research- Wave Phenomena