Time-dependent phase conjugation and four-wave mixing in plasmas

Journal Article · Fri Mar 01 04:00:00 EST 1991 · Physics of Fluids B; (USA)

DOI:https://doi.org/10.1063/1.859871· OSTI ID:5618284

Goldman, M V ^[1]; Williams, E A ^[2]

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1. Campus Box 391, University of Colorado, Boulder, Colorado 80309 (US)
2. Lawrence Livermore National Laboratory, L472, Box 5508, Livermore, California 94550 (USA)

Time-dependent four-wave mixing and phase conjugation in plasmas are treated, taking into account resonant longitudinal plasma modes and effects of spatial nonuniformity. A space-time formulation of four-wave processes in the ponderomotive force regime yields linearized equations, which are solved analytically as a combined initial/boundary-value problem in slab and inhomogeneous geometries. The plasma response is incorporated in a grating'' Green's function, expressed in terms of linear quasilongitudinal susceptibilities. Response times, decay times, and absolute instabilities are treated analytically. Plasma nonuniformity can speed up the response of the conjugate wave and modify resonant absolute instability thresholds. A new class of resonant absolute instabilities occurs when the counterpropagating pump waves have unequal intensities. The thresholds can be rather low for pump waves of modest intensity, provided the resonant grating has a long lifetime. Below these thresholds, regimes of stable amplification of the phase-conjugate wave relative to the incident signal are possible with pumps of unequal intensity.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5618284
• Journal Information: Physics of Fluids B; (USA), Journal Name: Physics of Fluids B; (USA) Vol. 3:3; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
ABSOLUTE INSTABILITIES
ANALYTICAL SOLUTION
BOUNDARY-VALUE PROBLEMS
DOCUMENT TYPES
EQUATIONS
FUNCTIONS
GREEN FUNCTION
INHOMOGENEOUS PLASMA
INSTABILITY
MAGNETIC FIELDS
NONLINEAR PROBLEMS
PLASMA
PLASMA INSTABILITY
RESONANCE
REVIEWS
SLABS
STEADY-STATE CONDITIONS
TIME DEPENDENCE
TRANSIENTS