Narrow Raman spectra: The competition between collisional and Landau damping

Journal Article · Wed Nov 01 04:00:00 EST 1989 · Physics of Fluids B: Plasma Physics; (USA)

DOI:https://doi.org/10.1063/1.859037· OSTI ID:5349846

Drake, R P; Williams, E A; Young, P E; Estabrook, K; Kruer, W L; Montgomery, D S ^[1]; Baldis, H A ^[2]; Johnston, T W ^[3]

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1. Lawrence Livermore National Laboratory, Livermore, California 94550 (US)
2. National Research Council, Ottawa, Ontario K1A 0R6, Canada
3. INRS-Energie, Varennes, Quebec, J0L 2P0, Canada

Narrow Raman spectra can be produced when the collisional damping rate becomes comparable to the homogeneous growth rate for stimulated Raman scattering (SRS). Landau damping limits the SRS spectrum at short wavelength, and collisional damping can limit it at long wavelength through the variation of the damping rate with plasma density. Data are shown to demonstrate this effect for the first time, from experiments in which constant-intensity pulses of 0.35 {mu}m light irradiated 3 {mu}m thick CH targets at intensities up to 2{times}10{sup 14} W/cm{sup 2}. The observed spectra have a peak wavelength, spectral width, spectral shape, and shift of the peak in time that are consistent with the anticipated effects of damping. Reduction of the emission from the plasma to near thermal levels at heavily damped frequencies is also demonstrated. In addition, the application of two specific models of SRS to these data is discussed.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5349846
• Journal Information: Physics of Fluids B: Plasma Physics; (USA), Journal Name: Physics of Fluids B: Plasma Physics; (USA) Vol. 1:11; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
700108 -- Fusion Energy-- Plasma Research-- Wave Phenomena
COHERENT SCATTERING
COLLISIONAL PLASMA
COLLISIONS
DAMPING
ELECTRON COLLISIONS
ELECTRON-ION COLLISIONS
INSTABILITY GROWTH RATES
ION COLLISIONS
LANDAU DAMPING
PLASMA
RAMAN EFFECT
RAMAN SPECTRA
SCATTERING
SPECTRA