Stimulated Brillouin scattering in long-scale-length laser plasmas

Journal Article · Wed Apr 01 04:00:00 EST 1998 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.872640· OSTI ID:625848

Chirokikh, A ^[1]; Seka, W ^[2]; Simon, A ^[1]; Craxton, R S ^[2]; Tikhonchuk, V T ^[3]

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1. Department of Mechanical Engineering, University of Rochester, Rochester, New York14627 (United States)
2. Laboratory for Laser Energetics, 250 East River Road, Rochester, New York14623 (United States)
3. P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow117924 (Russia)

Brillouin scattering from a preformed, inhomogeneous, expanding plasma has been investigated. Backscattered light near the incident laser wavelength ({lambda}=1054 nm) from CH planar targets has been spectrally and temporally resolved. By varying the time delay of the interaction beam, the scattering was studied for different plasma conditions. The backscattered light is predominantly blue-shifted and appears before the peak of the laser pulse. The experimental time-integrated reflectivity of backscattered light is in the range of 1{percent}{endash}10{percent} and decreases with the plasma density. The time-resolved spectra and total reflectivity were calculated using a theory of convective stimulated Brillouin scattering (SBS) in a flowing inhomogeneous plasma combined with a statistical hot spot model for the interaction beam. The plasma parameters for these calculations were provided by simulations using a two-dimensional hydrodynamic code. The calculated SBS spectra are similar to the experimental observations. The time-integrated reflectivities agree well with the experimental results for the higher peak density interactions, but are below the observations by orders of magnitude for the lowest peak density cases. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 625848
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 4 Vol. 5; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BACKSCATTERING
BRILLOUIN EFFECT
INHOMOGENEOUS PLASMA
LIGHT SCATTERING
PARAMETRIC INSTABILITIES
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA INSTABILITY
REFLECTIVITY