Harmonic generation in a moving plasma

Journal Article · Sat Jul 01 04:00:00 EDT 1978 · Sov. J. Plasma Phys. (Engl. Transl.); (United States)

OSTI ID:6461304

Krupnova, L V; Silin, V P

A study is made of how plasma motion affects the generation of the harmonics (1/2) ..omega../sub 0/, (3/2) ..omega../sub 0/, and 2..omega../sub 0/ arising due to the resonant interaction of plasma waves with a pump wave of frequency ..omega../sub 0/. Intense harmonic generation is observed when there is a high level of Langmuir turbulence in the plasma. Since the parametric plasma turbulence may be associated with an absolute decay instability, harmonic generation will presumably be hindered if the absolute instability which generates plasmons capable of participating in the resonant generation is somehow suppressed. It is shown that plasma motion can suppress the absolute decay instability for long-wavelength plasmons capable of generating harmonics through resonant interaction with a pump wave. The existence of a wave-number region in which the absolute instability is suppressed leads to anisotropy in the harmonic generation, since an angular interval appears, governed by the plasma velocity, in which generation is forbidden. For the (3/2) ..omega../sub 0/ harmonic, this anisotropy can strongly affect the spectrum. If the plasma velocity is sufficiently high, harmonic generation is forbidden in all directions. It is shown that the spectrum of the (3/2) ..omega../sub 0/ harmonic can be used to determine the electron temperature, the plasma velocity in the vicinity where the density is one-fourth the critical value, and the velocities of the critical point and of the point with the density (9/4) n/sub c/.

• Research Organization: P. N. Lebedev Physics Institute, Academy of Sciences of the USSR, Moscow
• OSTI ID: 6461304
• Journal Information: Sov. J. Plasma Phys. (Engl. Transl.); (United States), Journal Name: Sov. J. Plasma Phys. (Engl. Transl.); (United States) Vol. 4:4; ISSN SJPPD
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
DECAY INSTABILITY
HARMONICS
INSTABILITY
LASER-PRODUCED PLASMA
OSCILLATIONS
PARAMETRIC INSTABILITIES
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA WAVES
PLASMONS
QUASI PARTICLES
TURBULENCE