Dependences of Amplitudes of Electron Waves and Growth Rates of Ion-Acoustic Waves on Boundary Conditions in a Beam-Plasma System

1970 ◽  
Vol 29 (4) ◽  
pp. 1106-1106 ◽  
Author(s):  
Ryohei Itatani ◽  
Tokuhiro Obiki ◽  
Osamu Fukumasa
Keyword(s):  
Boundary Conditions ◽  
Growth Rates ◽  
Acoustic Waves ◽  
Ion Acoustic Waves ◽  
Plasma System ◽  
Beam Plasma ◽  
Ion Acoustic

Solitary waves in an ion-beam-plasma system

1995 ◽  
Vol 53 (2) ◽  
pp. 235-243 ◽  
Author(s):  
Y. Nakamura ◽  
K. Ohtani
Keyword(s):  
Solitary Wave ◽  
Solitary Waves ◽  
Acoustic Waves ◽  
Ion Beam ◽  
Slow Mode ◽  
Plasma System ◽  
Ion Acoustic Wave ◽  
Beam Plasma ◽  
Ion Acoustic ◽  
Beam Mode

Solitary waves in an ion-beam-plasma system are investigated theoretically using the pseudo-potential method, including finite temperatures of plasma ions and beam ions. The beam velocity is high enough to avoid ion-ion instability. Three kinds of solitary waves are possible, corresponding to ion- acoustic waves and to fast and slow space-charge waves in the beam. To observe the formation of solitary waves from an initial positive pulse, numerical simulations are performed. For the slow beam mode, a smaller solitary wave appears at the leading part of the pulse, which is a result of negative nonlinearity and anomalous dispersion of the slow mode, and is the opposite behaviour to the cases of the ion-acoustic wave and to the fast beam mode. Overtaking collisions of a solitary wave with a fast-mode solitary wave or with a slow-mode solitary wave are simulated.

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.

Ion-acoustic shock waves in a degenerate dense plasma

2012 ◽  
Vol 79 (1) ◽  
pp. 65-68 ◽  
Author(s):  
M. S. ZOBAER ◽  
N. ROY ◽  
A. A. MAMUN
Keyword(s):  
Acoustic Waves ◽  
Dense Plasma ◽  
Reductive Perturbation Method ◽  
Nonlinear Propagation ◽  
Ion Acoustic Waves ◽  
Plasma System ◽  
Ion Acoustic ◽  
Astrophysical Objects ◽  
Basic Features ◽  
Ion Acoustic Shock Waves

AbstractA theoretical investigation on the nonlinear propagation of ion-acoustic waves in a degenerate dense plasma has been made by employing the reductive perturbation method. The Burger's equation has been derived, and numerically analyzed. The basic features of electrostatic shock structures have been examined. It has been shown that the plasma system under consideration supports the propagation of electrostatic shock structures. The implications of our results (obtained from this investigation) in compact astrophysical objects have been briefly discussed.

scholarly journals The Excitation of Ion-acoustic Waves by a Magnetic Pump in Cylindrical Geometry

1983 ◽  
Vol 36 (5) ◽  
pp. 675
Author(s):  
NF Cramer ◽  
IJ Donnelly
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Acoustic Waves ◽  
Pump Wave ◽  
Modulational Instability ◽  
Collisionless Plasma ◽  
Cylindrical Geometry ◽  
Alfvén Waves ◽  
Ion Acoustic Waves ◽  
Ion Acoustic

The modulational, parametric and purely 8rowing mode instabilities of a magnetic pump with a finite radial wavenumber in cylindrical geometry are investigated. The modulational instability is compared with the instability of a parallel propagating pump wave, and the growth rates are found to be similar. The growth rate of a pair of ion-acoustic waves is shown to be zero for a collisionless plasma, in agreement with less general results found previously. The growth rate in the collisional case is found to be nonzero. The purely growing mode growth rate is calculated for excitation of ionacoustic plus torsional Alfven waves.

scholarly journals High time resolution PFISR and optical observations of naturally enhanced ion acoustic lines

2009 ◽  
Vol 27 (4) ◽  
pp. 1457-1467 ◽  
Author(s):  
R. G. Michell ◽  
K. A. Lynch ◽  
C. J. Heinselman ◽  
H. C. Stenbaek-Nielsen
Keyword(s):  
High Resolution ◽  
Time Resolution ◽  
Acoustic Waves ◽  
Fast Moving ◽  
High Time ◽  
High Time Resolution ◽  
Ion Acoustic Waves ◽  
Raw Data ◽  
Ion Acoustic ◽  
Auroral Imaging

Abstract. Observations of naturally enhanced ion acoustic lines (NEIALs) taken with the Poker Flat Incoherent Scatter Radar (PFISR) using a mode with very high time resolution are presented. The auroral event took place over Poker Flat, Alaska on 8 February 2007 at 09:35 UT (~22:00 MLT), and the radar data are complemented by common-volume high-resolution auroral imaging. The NEIALs occurred during only one of the standard 15-s integration periods. The raw data of this time show very intermittent NEIALs which occur only during a few very short time intervals (≤1 s) within the 15-s period. The time sampling of the raw data, ~19 ms on average, allows study of the time development of the NEIALs, though there are indications that even finer time resolution would be of interest. The analysis is based on the assumption that the NEIAL returns are the result of Bragg scattering from ion-acoustic waves that have been enhanced significantly above thermal levels. The spectra of the raw data indicate that although the up- and down-shifted shoulders can both become enhanced at the same time, (within 19 ms), they are most often enhanced individually. The overall power in the up-and down-shifted shoulders is approximately equal throughout the event, with the exception of one time, when very large up-shifted power was observed with no corresponding down-shifted power. This indicates that during the 480 μs pulse, the strongly enhanced ion-acoustic waves were only traveling downward and not upward. The exact time that the NEIALs occurred was when the radar beam was on the boundary of a fast-moving (~10 km/s), bright auroral structure, as seen in the high resolution auroral imaging of the magnetic zenith. When viewed with high time resolution, the occurrence of NEIALs is associated with rapid changes in auroral luminosity within the radar field of view due to fast-moving auroral fine structures.

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