scholarly journals Plasma Capacitor with Ion Acoustic Waves

1974 ◽  
Vol 29 (6) ◽  
pp. 851-858 ◽  
Author(s):  
F. Leuterer
Keyword(s):  
Magnetic Field ◽  
Velocity Distribution ◽  
Acoustic Waves ◽  
Radius Of Gyration ◽  
Ion Acoustic Waves ◽  
Homogeneous Plasma ◽  
Ion Acoustic ◽  
Zero Radius ◽  
The Magnetic Field ◽  
Plasma Capacitor

We examine experimentally and theoretically the r. f. potential within a capacitor, filled with a homogeneous plasma in a magnetic field and driven at frequencies ωci <ω<4ωci . We assume the ions to be cold, and the electrons to have a Maxwellian velocity distribution along the magnetic field, but zero radius of gyration. Thus ion acoustic waves are included. The whole kz-spectrum of the exciter is needed to explain the experimental results.

scholarly journals Ion acoustic waves near a comet nucleus: Rosetta observations at comet 67P/Churyumov–Gerasimenko

2021 ◽  
Vol 39 (1) ◽  
pp. 53-68
Author(s):  
Herbert Gunell ◽  
Charlotte Goetz ◽  
Elias Odelstad ◽  
Arnaud Beth ◽  
Maria Hamrin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Acoustic Waves ◽  
Magnetic Field Gradient ◽  
Ion Acoustic Waves ◽  
Ion Distributions ◽  
Ion Acoustic ◽  
Low Energies ◽  
The Waves ◽  
Comet 67P ◽  
The Magnetic Field

Abstract. Ion acoustic waves were observed between 15 and 30 km from the centre of comet 67P/Churyumov–Gerasimenko by the Rosetta spacecraft during its close flyby on 28 March 2015. There are two electron populations: one cold at kBTe≈0.2 eV and one warm at kBTe≈2 eV. The ions are dominated by a cold (a few hundredths of electronvolt) distribution of water group ions with a bulk speed of (3–3.7) km s−1. A warm kBTe≈6 eV ion population, which also is present, has no influence on the ion acoustic waves due to its low density of only 0.25 % of the plasma density. Near closest approach the propagation direction was within 50∘ from the direction of the bulk velocity. The waves, which in the plasma frame appear below the ion plasma frequency fpi≈2 kHz, are Doppler-shifted to the spacecraft frame where they cover a frequency range up to approximately 4 kHz. The waves are detected in a region of space where the magnetic field is piled up and draped around the inner part of the ionised coma. Estimates of the current associated with the magnetic field gradient as observed by Rosetta are used as input to calculations of dispersion relations for current-driven ion acoustic waves, using kinetic theory. Agreement between theory and observations is obtained for electron and ion distributions with the properties described above. The wave power decreases over cometocentric distances from 24 to 30 km. The main difference between the plasma at closest approach and in the region where the waves are decaying is the absence of a significant current in the latter. Wave observations and theory combined supplement the particle measurements that are difficult at low energies and complicated by spacecraft charging.

Dynamics of nonlinear ion-acoustic waves in an external magnetic field

1985 ◽  
Vol 44 (8) ◽  
pp. 537-543 ◽  
Author(s):  
E. Infeld ◽  
P. Frycz ◽  
T. Czerwiśka-Lenkowska
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Acoustic Waves ◽  
Ion Acoustic Waves ◽  
Ion Acoustic

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

1989 ◽  
Vol 41 (1) ◽  
pp. 83-88 ◽  
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.

Self-focusing of nonlinear ion-acoustic waves and solitons in magnetized plasmas. Part 2. Numerical simulations, two-soliton collisions

1987 ◽  
Vol 37 (1) ◽  
pp. 97-106 ◽  
Author(s):  
E. Infeld ◽  
P. Frycz
Keyword(s):  
Magnetic Field ◽  
Numerical Simulations ◽  
Growth Rates ◽  
Nonlinear Waves ◽  
Acoustic Waves ◽  
Ion Acoustic Waves ◽  
Self Focusing ◽  
Long Wave ◽  
Ion Acoustic ◽  
Soliton Collisions

Nonlinear waves and solitons satisfying the Zakharov-Kuznetsov equation for a dilute plasma immersed in a strong magnetic field are studied numerically. Growth rates of perpendicular instabilities, found theoretically in part 1, are confirmed and extended to arbitrary wavelengths of the perturbations (the calculations of part 1 were limited to long-wave perturbations). The effects of instabilities on nonlinear waves and solitons are illustrated graphically. Pre-vious, approximate results of other authors on the perpendicular growth rates for solitons are improved on. Similar results for perturbed nonlinear waves are presented. The effects of two-soliton collisions on instabilities are investigated. Rather surprisingly, we find that the growth of instabilities can be retarded by collisions. Instabilities can also be transferred from one soliton to another in a collision. This paper can be read independently of part 1.

Long wavelength ion-acoustic waves in a magneto-plasma in a gravitational field

1970 ◽  
Vol 4 (3) ◽  
pp. 617-627 ◽  
Author(s):  
C. H. Liu
Keyword(s):  
Magnetic Field ◽  
Dispersion Relation ◽  
Static Magnetic Field ◽  
Acoustic Waves ◽  
Fluid Dynamic ◽  
Debye Length ◽  
Ion Acoustic Waves ◽  
Long Wavelength ◽  
Special Cases ◽  
Ion Acoustic

Ion-acoustic waves propagating in a collision-free, gravity-supported plasma in a static magnetic field are studied with a linearized Vlasov equation. The dispersion relation is derived in the limit of vanishing electron to ion mass ratio and wavelength much larger than the Debye length. From this dispersion relation it is shown that the well-known fluid dynamic steepening tendency of waves propagating in the direction of decreasing density is competing with the effect of Landau damping. Depending on the ratio of electron and ion temperatures, the direction of propagation and the strength of the static magnetic field, waves of wavelengths of the order of the scale height or even greater are shown to be damped. Several special cases are discussed.

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