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.

Electron whistler mode instability in an inhomogeneous thermal plasma in the presence of an inhomogeneous beam of suprathermal electrons

1983 ◽  
Vol 29 (3) ◽  
pp. 439-448 ◽  
Author(s):  
H.A. Shah ◽  
V.K. Jain
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Dispersion Relation ◽  
Thermal Plasma ◽  
Uniform Magnetic Field ◽  
Inhomogeneous Plasma ◽  
Mode Instability ◽  
Whistler Mode ◽  
Suprathermal Electrons ◽  
Whistler Mode Waves

The excitation of the whistler mode waves propagating obliquely to the constant and uniform magnetic field in a warm and inhomogeneous plasma in the presence of an inhomogeneous beam of suprathermal electrons is studied. The full dispersion relation including electromagnetic effects is derived. In the electrostatic limit the expression for the growth rate is given. It is found that the inhomogeneities in both beam and plasma number densities affect the growth rates of the instabilities.

Nonlinear theory of a whistler wave

1975 ◽  
Vol 14 (3) ◽  
pp. 543-549 ◽  
Author(s):  
Takashi Yamamoto
Keyword(s):  
Growth Rate ◽  
Pitch Angle ◽  
Particle Distribution ◽  
Whistler Wave ◽  
Finite Width ◽  
Whistler Mode ◽  
Mode Spectrum ◽  
Numerical Result ◽  
Orbit Model ◽  
Resonance Function

Using the Dupree—Weinstock perturbed-orbit model of plasma turbulence, we obtain the diffusion equation describing the evolution of the average one-particle distribution function for whistler mode turbulence. The numerical result for electron pitch-angle diffusion within this scheme leads us to conclude that the effect of the resonance broadening due to perturbed orbits on the pitch-angle diffusion coefficient is not large compared with that evaluated by the unperturbed orbit in the whistler mode spectrum with a finite width. Based on the explicitly evaluated resonance function, the effects of this broadening on the growth rate for the whistler wave are also discussed.

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.

scholarly journals Interaction of an electron beam with whistler waves in magnetoplasmas

2015 ◽  
Vol 33 (3) ◽  
pp. 455-461 ◽  
Author(s):  
Ruby Gupta ◽  
Ved Prakash ◽  
Suresh C. Sharma ◽  
Vijayshri
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Electron Beam ◽  
Whistler Wave ◽  
Wave Number ◽  
Whistler Waves ◽  
Parallel Beam ◽  
Whistler Mode ◽  
Beam Velocity ◽  
The Magnetic Field

AbstractThe present paper studies the whistler wave interaction with an electron beam propagating through magnetized plasma. A dispersion relation of whistler waves has been derived, and first-order perturbation theory has been employed to obtain the growth rate of whistlers in the presence of parallel as well as oblique electron beam. For whistler waves propagating parallel to the magnetic field, that is, parallel whistlers, only the cyclotron resonance appears with a parallel beam, while for whistler waves propagating at an angle to the magnetic field, that is, oblique whistlers interaction with parallel beam or parallel whistlers interaction with oblique beam, the Cerenkov and the cyclotron resonances both appear. The growth rate is found to increase with an increase in the transverse component of beam velocity and with an increase in the strength of magnetic field. The whistler wave frequency decreases with an increase in the beam velocity. The obliqueness of the whistler mode modifies its dispersion characteristics as well as growth rate of the instability. For purely parallel-propagating beams, it is essential for the growth of whistler mode that the wave number perpendicular to the magnetic field should not be zero. The results presented may be applied to explain the mechanisms of the whistler wave excitation in space plasma.

Whistler instability in a magnetospheric duct

1989 ◽  
Vol 41 (2) ◽  
pp. 231-238 ◽  
Author(s):  
I. Talukdar ◽  
V. K. Tripathi ◽  
V. K. Jain
Keyword(s):  
Growth Rate ◽  
Perturbation Theory ◽  
Electron Beam ◽  
Gaussian Beam ◽  
Whistler Wave ◽  
Order Perturbation ◽  
First Order ◽  
Slow Cyclotron ◽  
Non Local ◽  
First Order Perturbation

A whistler wave propagating through a preformed magnetospheric duct is susceptible to growth/amplification by an electron beam. The interaction is non-local and could be of Čerenkov or slow-cyclotron type. First-order perturbation theory is employed to obtain the growth rate for flat and Gaussian beam densities.

scholarly journals Impact of hot injected beam on whistler mode with alternating electric field (AC) in the magnetosphere of Saturn

2021 ◽  
Vol 2062 (1) ◽  
pp. 012019
Author(s):  
Kumari Neeta Shukla ◽  
Devi Singh ◽  
R S Pandey
Keyword(s):  
Growth Rate ◽  
Distribution Function ◽  
Electric Field ◽  
Particle Interaction ◽  
Wide Frequency Range ◽  
Temperature Anisotropy ◽  
Mode Instability ◽  
Whistler Mode ◽  
Plasma Injection ◽  
Magnetosphere Of Saturn

Abstract Whistlers are believed to be generated by its own and responsible to evolve dynamical properties of magnetized planetary environment. Growing whistler instability can cause other uncertainties in the magnetosphere and evident to be generated by mean of injection events and temperature variance in plasma environment. In this paper the empirical dispersion relation has developed for parallel propagating whistler mode instability in an infinite saturnian magneto plasma in the presence of perpendicular electric field for ring distribution function having non-monotonous nature. Method of characteristics solutions alongside kinetic approach found to be most suitable in order to achieve perturbed plasma states. The perturbed and unperturbed particle trajectories have taken into consideration to determine perturbed distribution function. A remarkable growth rate expression with added hot plasma injection has been calculated in inner magnetosphere near 6.18 Rs. The results obtained using demonstrative value of the parameters suited to the Saturnian magnetosphere have been computed and discussed. Pressure (Temperature) anisotropy is found to be a peculiar source of free energy for whistler mode instability. The AC frequency irrespective of its magnitude, affects the growth rate significantly. The bulk of energetic hot electrons injection influences the growth rate by increasing its peak value. The result obtained provide the important view of wave particle interaction and useful to analyze the VLF emissions observed over a wide frequency range.

Sign in / Sign up

Export Citation Format

Share Document