Inhomogeneous two-plasmon instability

Journal Article · Sat Oct 01 04:00:00 EDT 1983 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.864037· OSTI ID:5591847

Simon, A; Short, R W; Williams, E A; Dewandre, T

The two-plasmon instability in warm inhomogeneous plasma for a normally incident pump is considered. The complex eigenfrequencies of the absolute instability are obtained by reducing the linearized fluid equations to a Schroedinger equation in wavenumber space. These eigenvalues are obtained in several ways. One is by combining a perturbation expansion in powers of the reciprocal scale length with WKB theory. The resulting algebraic equations are solved by three analytical approximations and by direct numerical solution. A second way is by analysis of the Schroedinger equation using an interactive WKB computer code. A third way is by the use of a shooting code. These methods are all used and compared for threshold curves and growth rates above threshold. Some eigenfunction forms are also obtained. The threshold is near (v/sub 0//v/sub e/)/sup 2/k/sub 0/ L = 3, and varies weakly with ..beta..approx. =v/sup 4//sub e//v/sup 2//sub 0/c/sup 2/, rising from near 2 to about 4 over six decades of variation of ..beta... The corresponding critical value of (k/sub y//k/sub 0/)/sup 2/ is near 0.2/..beta.. over this range. Above threshold, there is a smooth variation of the growth rate with (k/sub y//k/sub 0/)/sup 2/, peaking at some intermediate value. The perturbation method is in good agreement there with more exact calculations. Experimental implications of these results are discussed.

• Research Organization: Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623
• DOE Contract Number: AC08-80DP40124
• OSTI ID: 5591847
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 26:10; ISSN PFLDA
• 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
ANALYTICAL SOLUTION
COMPUTER CODES
DIFFERENTIAL EQUATIONS
EIGENVALUES
ELECTROMAGNETIC RADIATION
ENERGY
EQUATIONS
HOT PLASMA
INHOMOGENEOUS PLASMA
INSTABILITY
INSTABILITY GROWTH RATES
PARAMETRIC INSTABILITIES
PARTIAL DIFFERENTIAL EQUATIONS
PERTURBATION THEORY
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMONS
QUASI PARTICLES
RADIATIONS
SCHROEDINGER EQUATION
THRESHOLD ENERGY
WAVE EQUATIONS
WAVE PROPAGATION
WKB APPROXIMATION