Experimental studies of Raman scattering from foam targets using a 0. 35. mu. m laser beam

Journal Article · Sun Feb 01 04:00:00 EST 1987 · Phys. Fluids; (United States)

OSTI ID:6920457

Figueroa, H; Joshi, C; Clayton, C E

Experimental studies of the forward scattered spectrum and stimulated Raman backscattering from foam targets are presented. An attempt has been made to isolate the effects of the presence of the quarter critical density on the Raman spectrum by creating plasmas with various peak plasma densities. The plasmas created had a length larger than 600 ..mu..m and a variable peak density between 0.11n/sub c/ and slightly higher than 0.25n/sub c/. The total Raman reflectivity in the backward direction is of 0.3%, with 80% of its energy being scattered in a range of frequencies between 470 nm and 500 nm for all the targets used. The scattered intensity near the half-harmonic region shows a weak dependence on the presence of the n/sub c//4 density layer. The forward scattered spectrum obtained from targets with average densities between 0.11n/sub c/ and 0.22n/sub c/ shows a broadband of frequencies similar to the backscattered spectrum indicating that the forward spectrum is probably being seeded by the beating of the plasma wave from stimulated Raman backscattering (SRS-B) with the ion acoustic wave from stimulated Brillouin scattering (SBS).

• Research Organization: University of California, Los Angeles, California 90024
• OSTI ID: 6920457
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 30:2; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
COHERENT SCATTERING
ELECTROMAGNETIC RADIATION
LASER-PRODUCED PLASMA
PLASMA
PLASMA DENSITY
PULSES
RADIATIONS
RAMAN EFFECT
SCATTERING
TARGETS
VISIBLE RADIATION