Determination of wave growth from measured distribution functions and transport theory

A stability analysis which directly uses particle distribution functions determined from experiments or transport theory, rather than model distributions, is carried out. The features of distribution functions relevant to whistlers, ion cyclotron waves, including their low-frequency extensions for propagation along the magnetic field, and to ion-acoustic waves are analyzed in detail. The dependence of wave growth on the precise shape of the distributions and the numerical feasibility of the method is demonstrated by the use of measured solar wind distributions.

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On the numerical investigation of the interaction in plasma between (high & low) frequency of (Langmuir & ion-acoustic) waves

Results in Physics ◽

10.1016/j.rinp.2020.103317 ◽

2020 ◽

Vol 18 ◽

pp. 103317 ◽

Cited By ~ 6

Author(s):

Mostafa M.A. Khater ◽

Raghda A.M. Attia ◽

Choonkil Park ◽

Dianchen Lu

Keyword(s):

Numerical Investigation ◽

Acoustic Waves ◽

Low Frequency ◽

Ion Acoustic Waves ◽

Ion Acoustic

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Nonlinear ion-acoustic waves in a magnetized plasma and the Zakharov-Kuznetsov equation

Journal of Plasma Physics ◽

10.1017/s0022377800013672 ◽

1989 ◽

Vol 41 (1) ◽

pp. 83-88 ◽

Cited By ~ 22

Author(s):

Bhimsen K. Shivamoggi

Keyword(s):

Acoustic Waves ◽

Good Description ◽

Magnetized Plasma ◽

Stability Of Solutions ◽

Solitary Wave Solutions ◽

Ion Acoustic Waves ◽

Wave Solutions ◽

Ion Acoustic ◽

Analytical Properties ◽

The Magnetic Field

We consider here the nonlinear development of ion-acoustic waves in a magnetized plasma, and give a further discussion of the analytical properties of the Zakharov-Kuznestov equation that governs the latter problem. First we discuss the solitary-wave solutions and show that they give a good description of recent experimental results about the manner in which the magnetic field influences the solitary waves. We then exhibit recurrence and Lagrange stability of solutions of the Zakharov-Kuznestov equation.

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Nonlinear behaviour of a finite amplitude electron plasma wave - IV. Decay to ion cyclotron waves

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1978.0182 ◽

1978 ◽

Vol 363 (1715) ◽

pp. 547-557

Keyword(s):

Magnetic Field ◽

Low Frequency ◽

Electron Plasma ◽

Finite Amplitude ◽

Nonlinear Behaviour ◽

Electron Plasma Wave ◽

Ion Cyclotron Waves ◽

Ion Cyclotron ◽

Low Frequency Mode ◽

The Magnetic Field

Plasma in a magnetic field displays low frequency modes near the ion cyclotron frequency for waves propagating at an angle to the magnetic field. These modes are only slightly modified in a bounded plasma, and therefore can be excited by nonlinear decay of electron plasma waves which also propagate at an angle to the magnetic field. The nonlinearly generated low frequency mode has been identified experimentally as an ion cyclotron wave by stimulating the decay. The resonant matching conditions have also been demonstrated.

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Cluster observations and theoretical identification of broadband waves in the auroral region

Annales Geophysicae ◽

10.5194/angeo-23-3739-2005 ◽

2005 ◽

Vol 23 (12) ◽

pp. 3739-3752 ◽

Cited By ~ 6

Author(s):

M. Backrud-Ivgren ◽

G. Stenberg ◽

M. André ◽

M. Morooka ◽

Y. Hobara ◽

...

Keyword(s):

Electric Field ◽

Acoustic Waves ◽

Auroral Region ◽

Parallel Electric Field ◽

Ion Acoustic Waves ◽

Ion Cyclotron Waves ◽

Linear Waves ◽

Field Lines ◽

Broadband Waves ◽

The Waves

Abstract. Broadband waves are common on auroral field lines. We use two different methods to study the polarization of the waves at 10 to 180 Hz observed by the Cluster spacecraft at altitudes of about 4 Earth radii in the nightside auroral region. Observations of electric and magnetic wave fields, together with electron and ion data, are used as input to the methods. We find that much of the wave emissions are consistent with linear waves in homogeneous plasma. Observed waves with a large electric field perpendicular to the geomagnetic field are more common (electrostatic ion cyclotron waves), while ion acoustic waves with a large parallel electric field appear in smaller regions without suprathermal (tens of eV) plasma. The regions void of suprathermal plasma are interpreted as parallel potential drops of a few hundred volts.

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Numerical determination of the cutoff frequency in solar models

Astronomy and Astrophysics ◽

10.1051/0004-6361/202038387 ◽

2020 ◽

Vol 640 ◽

pp. A4 ◽

Cited By ~ 1

Author(s):

T. Felipe ◽

C. R. Sangeetha

Keyword(s):

Magnetic Field ◽

Wave Propagation ◽

Magnetic Fields ◽

Numerical Simulations ◽

Acoustic Waves ◽

Cutoff Frequency ◽

Quiet Sun ◽

Radiative Losses ◽

The Magnetic Field

Context. In stratified atmospheres, acoustic waves can only propagate if their frequency is higher than the cutoff value. The determination of the cutoff frequency is fundamental for several topics in solar physics, such as evaluating the contribution of the acoustic waves to the chromospheric heating or the application of seismic techniques. However, different theories provide different cutoff values. Aims. We developed an alternative method to derive the cutoff frequency in several standard solar models, including various quiet-Sun and umbral atmospheres. The effects of magnetic field and radiative losses on the cutoff are examined. Methods. We performed numerical simulations of wave propagation in the solar atmosphere using the code MANCHA. The cutoff frequency is determined from the inspection of phase-difference spectra computed between the velocity signal at two atmospheric heights. The process is performed by choosing pairs of heights across all the layers between the photosphere and the chromosphere to derive the vertical stratification of the cutoff in the solar models. Result. The cutoff frequency predicted by the theoretical calculations departs significantly from the measurements obtained from the numerical simulations. In quiet-Sun atmospheres, the cutoff shows a strong dependence on the magnetic field for adiabatic wave propagation. When radiative losses are taken into account, the cutoff frequency is greatly reduced and the variation of the cutoff with the strength of the magnetic field is lower. The effect of the radiative losses in the cutoff is necessary to understand recent quiet-Sun and sunspot observations. In the presence of inclined magnetic fields, our numerical calculations confirm that the cutoff frequency is reduced as a result of the reduced gravity experienced by waves that propagate along field lines. An additional reduction is also found in regions with significant changes in the temperature, which is due to the lower temperature gradient along the path of field-guided waves. Conclusions. Our results show solid evidence that the cutoff frequency in the solar atmosphere is stratified. The cutoff values are not correctly captured by theoretical estimates. In addition, most of the widely used analytical cutoff formulae neglect the effect of magnetic fields and radiative losses, whose role is critical for determining the evanescent or propagating nature of the waves.

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Numerical simulations of Zakharov’s (ZK) non-dimensional equation arising in Langmuir and ion-acoustic waves

Modern Physics Letters B ◽

10.1142/s0217984921504807 ◽

2021 ◽

pp. 2150480

Author(s):

Mostafa M. A. Khater

Keyword(s):

Acoustic Waves ◽

Electromagnetic Waves ◽

Low Frequency ◽

Expansion Method ◽

Ion Acoustic Waves ◽

B Spline ◽

Kudryashov Method ◽

Ion Acoustic ◽

Dimensional Equation ◽

The Relationship

The trigonometric quintic B-spline scheme is used in this research paper to research Zakharov’s (ZK) nonlinear dimensional equation’s numerical solution. The ZK model’s solutions explain the relationship between the high-frequency Langmuir and the low-frequency ion-acoustic waves with many applications in optical fiber, coastal engineering, and fluid mechanics of electromagnetic waves, plasma physics, and signal processing. Three recent computational schemes (the expanded [Formula: see text]-expansion method, generalized Kudryashov method, and modified Khater method) have recently been used to investigate this model’s moving wave solution. Many innovative solutions have been established in this paper to determine the original and boundary conditions that allow numerous numerical schemes to be implemented. Here, the trigonometric quintic B-spline method is used to analyze the precision of the collected analytical solutions. To illustrate the precision of the numerical and computational solutions, distinct drawings are depicted.

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Nonlinear propagation of ion-acoustic waves and low-frequency electrostatic modes in a dusty plasma

Journal of Plasma Physics ◽

10.1017/s002237780002688x ◽

1993 ◽

Vol 50 (1) ◽

pp. 37-44 ◽

Cited By ~ 3

Author(s):

U. A. Mofiz ◽

Madhabi Islam ◽

Zarin Ahmed

Keyword(s):

Dusty Plasma ◽

Acoustic Waves ◽

Wave Scattering ◽

Evolution Equations ◽

Low Frequency ◽

Nonlinear Propagation ◽

Ion Acoustic Waves ◽

Ion Acoustic ◽

Ion Acoustic Solitons

Nonlinear propagation of ion-acoustic waves and low-frequency electrostatic modes in a dusty plasma is investigated. The evolution equations of these modes are developed and solved analytically. It is found that for small grain charge usual ion-acoustic solitons may exist in a dusty plasma, but increasing grain charge destroys them and finally they may disappear. The low-frequency electrostatic mode may be localized, forming solitons, which may act as centres of wave scattering in a dusty plasma.

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Coupling between Electrostatic Ion Cyclotron Waves and Ion Acoustic Waves

Physical Review Letters ◽

10.1103/physrevlett.30.535 ◽

1973 ◽

Vol 30 (12) ◽

pp. 535-537 ◽

Cited By ~ 8

Author(s):

T. Ohnuma ◽

S. Miyake ◽

T. Watanabe ◽

T. Watari ◽

T. Sato

Keyword(s):

Acoustic Waves ◽

Ion Acoustic Waves ◽

Ion Cyclotron Waves ◽

Ion Acoustic ◽

Ion Cyclotron

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Ion plasma waves in dusty plasmas: Halley's comet

Journal of Plasma Physics ◽

10.1017/s0022377800013386 ◽

1988 ◽

Vol 40 (3) ◽

pp. 399-406 ◽

Cited By ~ 189

Author(s):

U. de Angelis ◽

V. Formisano ◽

M. Giordano

Keyword(s):

Acoustic Waves ◽

Low Frequency ◽

Dusty Plasmas ◽

Dust Particles ◽

Charged Dust ◽

Ion Acoustic Waves ◽

Common Space ◽

Halley's Comet ◽

Homogeneous Background ◽

Ion Waves

We investigate ion waves in a plasma in the presence of massive charged dust particles, a common space-plasma component now known to exist also in planetary rings and comets. We derive an equation describing low-frequency electrostatic perturbations on a non-homogeneous background, where the inhomogeneity is due to a distribution of charged grains, each surrounded by an equilibrium statistical distribution of plasma particles. This model is then applied to propose an interpretation of some recent data from the Vega and Giotto space probes to Halley's comet the increase of the low-frequency electrostatic noise (ion-acoustic waves) in the region of increased dust.

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