Observation of a Transition from Fluid to Kinetic Nonlinearities for Langmuir Waves Driven by Stimulated Raman Backscatter

Journal Article · Fri May 06 04:00:00 EDT 2005 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.94.175003· OSTI ID:20696241

Kline, J L; Montgomery, D S; Bezzerides, B; Cobble, J A; DuBois, D F; Johnson, R P; Rose, H A; Yin, L ^[1]; Vu, H X ^[2]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. University of California, San Diego, California 92093 (United States)

Thomson scattering is used to measure Langmuir waves (LW) driven by stimulated Raman scattering (SRS) in a diffraction limited laser focal spot. For SRS at wave numbers k{lambda}{sub D} < or approx. 0.29, where k is the LW number and {lambda}{sub D} is the Debye length, multiple waves are detected and are attributed to the Langmuir decay instability (LDI) driven by the primary LW. At k{lambda}{sub D} > or approx. 0.29, a single wave, frequency-broadened spectrum is observed. The transition from the fluid to the kinetic regime is qualitatively consistent with particle-in-cell simulations and crossing of the LDI amplitude threshold above that for LW self-focusing.

• OSTI ID: 20696241
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 17 Vol. 94; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DEBYE LENGTH
DECAY INSTABILITY
DIFFRACTION
FOCUSING
LASERS
NONLINEAR PROBLEMS
PLASMA
PLASMA SIMULATION
RAMAN EFFECT
THOMSON SCATTERING