Induced spatial incoherence effects on the convective Raman instability

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

DOI:https://doi.org/10.1063/1.860941· OSTI ID:6783786

Guzdar, P N; Liu, C S ^[1]; Lehmberg, R H ^[2]

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1. Laboratory for Plasma Research, University of Maryland, College Park, Maryland 20742-3511 (United States)
2. Naval Research Laboratory Washington, DC 20375-5000 (United States)

The effect of the induced spatial incoherence method of laser beam smoothing on the convective Raman instability in an underdense inhomogeneous plasma has been studied. It is found that only for bandwidths comparable to, or greater than, the time-averaged homogeneous growth rate, is there significant smoothing effect resulting in a reduction of the backscattered radiation. However, for narrow bandwidths the backscattered radiation computed in the presence of hot spots created by the echelons, turns out to be significantly less than the levels observed in the Naval Research Laboratory experiments. We argue that a combination of three-dimensional effects and filamentation may account for the observed level of enhanced scattering.

• OSTI ID: 6783786
• 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
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
700350 -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
BACKSCATTERING
BEAM-PLASMA SYSTEMS
CONVECTIVE INSTABILITIES
ELECTROMAGNETIC RADIATION
INHOMOGENEOUS PLASMA
INSTABILITY
LASER RADIATION
PLASMA
PLASMA INSTABILITY
RADIATIONS
RAMAN EFFECT
RAYLEIGH-TAYLOR INSTABILITY
SCATTERING