Effects of density scale length on backward and forward stimulated Raman scattering in 0. 53 [mu]m laser--plasma interaction

Journal Article · Mon Mar 01 04:00:00 EST 1993 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860942· OSTI ID:6783765

Rousseaux, C; Amiranoff, F; Labaune, C; Matthieussent, G ^[1]

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1. Laboratoire pour l'Utilisation des Lasers Intenses, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

Forward and backward stimulated Raman scattering (SRS) have been investigated in three different plasma geometries: in exponential density profile, in Gaussian density profile, and in quasihomogeneous preformed plasmas. The experiments were performed with the same irradiation setup at 0.53 [mu]m wavelength and at a laser intensity [similar to]10[sup 15] W/cm[sup 2]. Time-resolved spectra and energy rates of this instability have been measured in the three experiments. A strong increase of the backward SRS energy rate---up to 1%---with the increasing length of the plasma was observed. From data analysis, backward SRS is explained in terms of absolute instability. On the other hand, forward SRS can be interpreted by considering linear scattering of the incident laser light on the plasma wave driven by backward SRS. This assumption is adequately supported both by the spectral characteristics and by the energy rates of the forward emission light.

• OSTI ID: 6783765
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 5:3; ISSN PFBPEI; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700350* -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
ABSOLUTE INSTABILITIES
BACKSCATTERING
ELECTROMAGNETIC RADIATION
ELECTRON PLASMA WAVES
INFRARED RADIATION
INSTABILITY
LASER-PRODUCED PLASMA
NEAR INFRARED RADIATION
PARAMETRIC INSTABILITIES
PLASMA
PLASMA DENSITY
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA WAVES
RADIATIONS
RAMAN EFFECT
SCATTERING