Parametric decay of an electromagnetic wave near electron cyclotron harmonics

Journal Article · Thu Jun 01 04:00:00 EDT 1995 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871295· OSTI ID:165288

Istomin, Y N ^[1]; Leyser, T B ^[2]

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1. P. N. Lebedev Physical Institute, Leninsky Prospect 53, 117924 Moscow (Russian Federation)
2. Swedish Institute of Space Physics, P.O. Box 812, S-981 28 Kiruna (Sweden)

A system of equations describing the nonlinear coupling of high frequency electron Bernstein (EB) and upper hybrid (UH) waves near harmonics of the electron cyclotron frequency with low frequency lower hybrid (LH) waves in a homogeneous, weakly magnetized, and weakly collisional plasma is derived. The EB and UH modes are described by a single second order equation, taking into account the interaction with low frequency density fluctuations. The ponderomotive force of the high frequency oscillations increases near the cyclotron harmonics due to the resonance with the electron motion. The obtained equations are used to study the parametric decay of an infinite wavelength electromagnetic pump wave into EB or UH waves and LH waves. The threshold electric fields are sufficiently low to be exceeded in high frequency ionospheric modification experiments. However, the instability cannot be excited for pump frequencies near the cyclotron harmonics. For the decay into EB waves, the resulting forbidden frequency range depends on the harmonic number in a power law manner, consistent with observations of stimulated electromagnetic emissions in ionospheric modification experiments. Further, for sufficiently high pump electric fields the instability is also suppressed, when the frequency mismatch around the eigenfrequencies at which the interaction can occur is of the order of the frequency separation between the EB and UH modes near the cyclotron harmonics. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

• OSTI ID: 165288
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 6 Vol. 2; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BERNSTEIN MODE
COLLISIONAL PLASMA
CYCLOTRON HARMONICS
ELECTRON CYCLOTRON-RESONANCE
HOMOGENEOUS PLASMA
IONOSPHERE
PONDEROMOTIVE FORCE