scholarly journals Parametric up-conversion of a trivelpiece–gould mode in a beam–plasma system

2004 ◽  
Vol 22 (1) ◽  
pp. 89-94 ◽  
Author(s):  
D.N. GUPTA ◽  
A.K. SHARMA
Keyword(s):  
Growth Rate ◽  
Pump Wave ◽  
Parametric Instability ◽  
Density Perturbation ◽  
Wave Number ◽  
Plasma System ◽  
Beam Density ◽  
Beam Plasma ◽  
Half Power ◽  
Beam Mode

A large amplitude Trivelpiece–Gould (TG) mode, in a strongly magnetized beam–plasma system, parametrically couples to a beam space charge mode and a TG mode sideband. The density perturbation associated with the beam mode couples with the electron oscillatory velocity, due to the pump wave, to produce a nonlinear current, driving the sideband. The pump and the sideband waves exert a ponderomotive force on the electrons with a component parallel to the ambient magnetic field, driving the beam mode. For a pump wave having k0·v0b0/ω0 < 0, where ω0, k0 are the frequency and the wave number of the pump, and v0b0 is the beam velocity, the sideband is frequency upshifted. At low beam density (Compton regime) the growth rate of the parametric instability scales as two-thirds power of the pump amplitude, and one-third power of beam density. In the Raman regime, the growth rate scales as half power of beam density and linearly with pump amplitude. The background plasma has a destabilizing role on the instability.

Fourier Analysis of the Wave Number of Unstable Waves in a Spiral Beam-Plasma System

1983 ◽  
Vol 22 (Part 1, No. 5) ◽  
pp. 842-843
Author(s):  
Toshitaka Idehara ◽  
Kunihiko Usami
Keyword(s):  
Fourier Analysis ◽  
Wave Number ◽  
Plasma System ◽  
Beam Plasma ◽  
Spiral Beam

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.

Observation of solitary waves in an ion-beam–plasma system

1998 ◽  
Vol 60 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Y. NAKAMURA ◽  
K. KOMATSUDA
Keyword(s):  
Solitary Waves ◽  
Ion Beam ◽  
Density Ratio ◽  
Maximum Amplitude ◽  
Plasma System ◽  
Measured Velocity ◽  
Beam Plasma ◽  
Plasma Device ◽  
Double Plasma Device ◽  
Beam Mode

Propagation of nonlinear space-charge waves in an ion-beam–plasma system is investigated in a double-plasma device. The velocity of the beam is high enough to avoid ion–ion instability. The density ratio of the beam to the plasma is kept high ([les ]0.6), which makes the maximum amplitude of solitary waves large. The measured velocity and width of the compressional solitary waves of the fast and the slow beam mode are compared with predictions of the pseudopotential method in which the temperatures of beam and plasma ions are taken into consideration. Reasonable agreement is obtained between the experimental and theoretical results.

Excitation of whistler mode instability due to slow cyclotron interaction in an inhomogenous beam–plasma System

1984 ◽  
Vol 31 (2) ◽  
pp. 225-229 ◽  
Author(s):  
H. A. Shah ◽  
V. K. Jain
Keyword(s):  
Growth Rate ◽  
Inhomogeneous Plasma ◽  
Whistler Wave ◽  
Wave Instability ◽  
Mode Instability ◽  
Plasma System ◽  
Whistler Mode ◽  
Beam Plasma ◽  
Slow Cyclotron ◽  
Dielectric Tensors

The excitation of whistler wave instability due to slow cyclotron (m = – 1) interaction in an inhomogeneous plasma penetrated by an inhomogeneous beam of electrons is studied. Expressions are obtained for the elements of the plasma and beam dielectric tensors. It is shown that the inhomogeneity in both beam and plasma number densities affects the growth rate of the instability.

Dressed ion acoustic soliton in an ion-beam plasma system

1988 ◽  
Vol 66 (9) ◽  
pp. 824-829 ◽  
Author(s):  
Yashvir ◽  
R. S. Tiwari ◽  
S. R. Sharma
Keyword(s):  
Ion Beam ◽  
Reductive Perturbation Method ◽  
Renormalization Procedure ◽  
Plasma System ◽  
Beam Density ◽  
Beam Velocity ◽  
Beam Plasma ◽  
Reductive Perturbation ◽  
Ion Acoustic ◽  
Ion Acoustic Soliton

Propagation of an ion-acoustic soliton in an ion-beam plasma system is studied using the renormalization procedure of Kodama and Taniuti in the reductive perturbation method and an alternative method. Expressions for the first- and second-order potentials are derived. The effects of beam velocity and beam density on the amplitude and the width of the solitons, for different ion-mass ratios, are considered. It is found that (i) the amplitude decreases with the increase of beam density, and (ii) there is a critical beam velocity, below which a stationary soliton cannot exist in an ion-beam plasma system.

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