Coherent generation of the auroral kilometric radiation by nonlinear beatings between electrostatic waves

Journal Article · Sat Sep 01 00:00:00 EDT 1979 · J. Geophys. Res.; (United States)

OSTI ID:5751414

Pellat, R; Roux, A

The propagation of electrostatic plasma waves in an inhomogeneous and magnetized plasma is studied analytically. These waves, which are driven unstable by auroral beams of electrons, are shown to suffer a further geometrical amplification while they propagate toward cut-off. Simultaneously their group velocities tend to be aligned with the geomagnetic field. Then it is shown that the electrostatic energy tends to accumulate at or near ..omega../sub L/H and ..omega../sub U/H, the local lower and upper hybrid frequencies. Due to this process, large amplitude electrostatic waves with very narrow spectra should be observed near these frequencies at any place along the auroral field lines where intense beam driven instability takes place. These intense quasi-monochromatic electrostatic waves are then shown to give rise by a coherent nonlinear three wave process to an intense electromagnetic radiation. Provided that the ratio ..omega../sub p/e/..omega../sub c/e tends to be smaller than unity, it is shown that the most intense radiation should be observed at 2..omega../sub U/H in the extraordinary mode.

• Research Organization: Centre de Physique Theorique de l'Ecole Polytechnique Plateau de Palaiseau, 91128 Palaiseau, Cedex, France
• OSTI ID: 5751414
• Journal Information: J. Geophys. Res.; (United States), Vol. 84:A9
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
INHOMOGENEOUS PLASMA
PLASMA WAVES
AURORAE
PLANETARY IONOSPHERES
PLASMA INSTABILITY
RADIOWAVE RADIATION
SPECTRAL DENSITY
WAVE PROPAGATION
ELECTROMAGNETIC RADIATION
FUNCTIONS
INSTABILITY
PLASMA
RADIATIONS
SPECTRAL FUNCTIONS
700108* - Fusion Energy- Plasma Research- Wave Phenomena