Theory for low-frequency modulated Langmuir wave packets

1992 ◽  
Vol 19 (22) ◽  
pp. 2187-2190 ◽  
Author(s):  
Iver H. Cairns ◽  
P. A. Robinson
Keyword(s):  
Wave Packets ◽  
Low Frequency ◽  
Langmuir Wave

Statistical Analysis of Langmuir Waves Associated with Type III Radio Bursts: II. Simulation and Interpretation of the Wave Energy Distributions

2011 ◽  
Vol 20 (4) ◽  
Author(s):  
M. Maksimović ◽  
S. Vidojević ◽  
A. Zaslavsky
Keyword(s):  
Wave Energy ◽  
Probability Distributions ◽  
Wave Packets ◽  
Low Frequency ◽  
Langmuir Wave ◽  
Type I ◽  
Energy Distributions ◽  
Langmuir Waves ◽  
Pearson Type ◽  
Log Normal

AbstractWe have modeled electrostatic Langmuir waves by an electric field, consisting of superposition of Gaussian wave packets with several probability distributions of amplitudes and with several Poisson distributions of wave packets. The outcome of the model is that the WIND satellite observations, especially in the low frequency domain (the WAVES experiment), do not allow to conclude whether the input wave amplitude distributions are closer to the log-normal than to the Pearson type I or uniform. The average number of wave packets in 1 s is found to be between 0.1 and 50. Therefore, there is a clear need to measure Langmuir wave energy distributions directly at the waveform level, not a posteriori in the spectral domain. This is planned to be implemented on the RPW (Radio and Plasma Wave Analyzer) instrument in the Solar Orbiter mission.

Decay Instability of an Electromagnetic Wave Incident on a Weakly-Inhomogeneous Magnetised Plasma

1982 ◽  
Vol 37 (2) ◽  
pp. 97-101
Author(s):  
Bhimsen K. Shivamoggi
Keyword(s):  
Electromagnetic Wave ◽  
Pump Wave ◽  
Low Frequency ◽  
Langmuir Wave ◽  
Density Perturbation ◽  
Threshold Value ◽  
Wave Incident ◽  
Ion Acoustic Wave ◽  
Decay Instability ◽  
Electromagnetic Wave Incident

Abstract This paper considers the parametric decay of an electromagnetic wave incident on a weakly-inhomogeneous magnetised plasma into a Langmuir wave and an ion-acoustic wave. The Vlasov model is used in order to calculate the low-frequency electron-density perturbation produced by the beating of the side-band modes with the pump wave. The results show that the threshold value of the pump wave to undergo a decay instability drops in the presence of an inhomogeneity in the plasma.

Nonlinear Landau damping of large-amplitude Langmuir waves and formation of standing nonlinear waves

1980 ◽  
Vol 23 (3) ◽  
pp. 475-482 ◽  
Author(s):  
V. P. Pavlenko
Keyword(s):  
Thermal Plasma ◽  
Nonlinear Waves ◽  
Wave Packets ◽  
Langmuir Wave ◽  
Landau Damping ◽  
Characteristic Scale ◽  
Langmuir Waves ◽  
Slowing Down ◽  
Mechanism Of Interaction ◽  
Nonlinear Landau Damping

The interaction of nonlinear Langmuir wave packets corresponding to periodic solutions of the nonlinear Schrödinger equation with thermal plasma particles is considered. The mechanism of interaction is nonlinear Landau damping. The wave packets are slowed down owing to interaction but their amplitudes remain essentially unchanged. The characteristic scale lengths of the slowing down are determined.

scholarly journals Four-wave Processes Involving Two Low Frequency Waves

1986 ◽  
Vol 39 (6) ◽  
pp. 891 ◽  
Author(s):  
DB Melrose
Keyword(s):  
Transverse Wave ◽  
Major Part ◽  
Nonlinear Response ◽  
Interplanetary Medium ◽  
Wave Process ◽  
Low Frequency ◽  
Langmuir Wave ◽  
Sound Waves ◽  
Wave Processes ◽  
Low Frequency Waves

The probability is calculated for a four-wave process in which a Langmuir wave combines with two low frequency (ion sound) waves to produce another Langmuir wave or a transverse wave. The major part of the calculation involves relevant approximations to the quadratic and cubic nonlinear response tensors. An estimate based on observational data from the interplanetary medium suggests that the four-wave process may be significant in solar radiophysics.

scholarly journals The Connection between Coherent Structures and Low-Frequency Wave Packets in Large-Scale Atmospheric Flow

2004 ◽  
Vol 61 (21) ◽  
pp. 2616-2626 ◽  
Author(s):  
Daniel Hodyss ◽  
Terrence R. Nathan
Keyword(s):  
Coherent Structures ◽  
Large Scale ◽  
Wave Packets ◽  
Low Frequency ◽  
Wave Groups ◽  
Atmospheric Flow ◽  
Subsequent Formation ◽  
Frequency Wave ◽  
Wave Focusing ◽  
Group Velocities

Abstract A theory is presented that addresses the connection between low-frequency wave packets (LFWPs) and the formation and decay of coherent structures (CSs) in large-scale atmospheric flow. Using a weakly nonlinear evolution equation as well as the nonlinear barotropic vorticity equation, the coalescence of LFWPs into CSs is shown to require packet configurations for which there is a convergent group velocity field. These LFWP configurations, which are consistent with observations, have shorter wave groups with faster group velocities upstream of longer wave groups with slower group velocities. These wave group configurations are explained by carrying out a kinematic analysis of wave focusing, whereby a collection of wave groups focus at some point in space and time to form a large amplitude wave packet having a single wave front. The wave focusing and the subsequent formation of CSs are enhanced by zonal variations in the background flow, while nonlinearity extends the lifetimes of the CSs. These results are discussed in light of observed blocking formation in the Atlantic–European and South Pacific regions.

Breakup and reconstitution of Langmuir wave packets

1981 ◽  
Vol 24 (1) ◽  
pp. 182 ◽  
Author(s):  
T. Tajima
Keyword(s):  
Wave Packets ◽  
Langmuir Wave

scholarly journals Oscillating two stream instability of a plasma wave in a negative ion containing plasma with hot and cold positive ions

2007 ◽  
Vol 25 (3) ◽  
pp. 397-406 ◽  
Author(s):  
Hitendra K. Malik
Keyword(s):  
Plasma Wave ◽  
Plasma Frequency ◽  
Low Frequency ◽  
Langmuir Wave ◽  
Negative Ions ◽  
Negative Ion ◽  
Charge Number ◽  
Long Wavelength ◽  
Positive Ions ◽  
Stream Instability

An oscillating two-stream instability (OTSI) is investigated in plasma, which has hot and cold positive ions, negative ions, and the electrons. For this, a long wavelength plasma wave is considered to be driven by two copropagating lasers with frequencies ωL1 and ωL2, such that their difference is almost equal to the electron plasma frequency ωp. In the present mechanism, this plasma beat wave (ωb, kb) is taken to grow in amplitude, so that it becomes susceptible to the OTSI and produces a low frequency electrostatic mode (ω, k), and two shorter wavelength Langmuir wave sidebands (ω1, k1) and (ω2, k2) with ω1 = ω − ωb, ω2 = ω + ωb, k1 = k − kb, and k2 = k + kb in the plasma. The effects of charge number Z, mass, temperature, and density of the ions are studied on the growth rate of the instability, and the amplitudes and phases of the sideband waves generated during the OTSI. It is found that the effects of charge number and mass of the ions are significant on the instability.

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