Electromagnetic linear dispersion relation for plasma with a drift across magnetic field revisited

2018 ◽  
Vol 25 (10) ◽  
pp. 102109 ◽  
Author(s):  
Takayuki Umeda ◽  
Takuma K. M. Nakamura
2002 ◽  
Vol 30 (3) ◽  
pp. 1134-1146 ◽  
Author(s):  
K. Minami ◽  
M. Saito ◽  
Y. Choyal ◽  
K.P. Maheshwari ◽  
V.L. Granatstein

1984 ◽  
Vol 32 (1) ◽  
pp. 55-80 ◽  
Author(s):  
Z. G. An ◽  
Y. C. Lee ◽  
T. T. Lee ◽  
H. H. Chen

Electromagnetic cyclotron instabilities of a relativistic electron beam propagating in an external magnetic field are studied by considering electron motion inside a self-consistent electromagnetic field. When the number of electrons in a subgroup is greater than two, or when the phases are random, the linear dispersion relation obtained agrees with that of Chu et al. for a gyrotron in a ring model. When the number of electrons in a subgroup is limited to two only, the linear dispersion relation is different in that it has an instability threshold. Completely nonlinear motion is also studied using the method of Poincaré's return map, or by considering the departure rate of nearby trajectories. Stochasticity is observed in the nonlinear oscillation of the wave-particle system when a critical energy is exceeded. Physical implications for gyrotron operation are also discussed.


2008 ◽  
Vol 74 (1) ◽  
pp. 107-110 ◽  
Author(s):  
P. K. SHUKLA

AbstractThe linear dispersion relation for compressional magnetoacoustic waves in a quantum magnetoplasma is derived, taking into account the quantum Bohm potential and the magnetization of electrons due to the electron-1/2 spin effect. It is found that the quantum forces produce the wave dispersion at quantum scales, which depend on the external magnetic field strength.


Author(s):  
Quentin Fontaine ◽  
Agostino Apra ◽  
Giovanni Lerario ◽  
Elisabeth Giacobino ◽  
Alberto Bramati ◽  
...  

2010 ◽  
Vol 77 (3) ◽  
pp. 357-365 ◽  
Author(s):  
B. DASGUPTA ◽  
DASTGEER SHAIKH ◽  
P. K. SHUKLA

AbstractWe derive a generalized linear dispersion relation of waves in a strongly magnetized, compressible, homogeneous and isotropic quasi-neutral plasma. Starting from a two-fluid model, describing distinguishable electron and ion fluids, we obtain a six-order linear dispersion relation of magnetized waves that contains effects due to electron and ion inertia, finite plasma beta and angular dependence of phase speed. We investigate propagation characteristics of these magnetized waves in a regime where scale lengths are comparable with electron and ion inertial length scales. This regime corresponds essentially to the solar wind plasma, where length scales, comparable with ion cyclotron frequency, lead to dispersive effects. These scales in conjunction with linear waves present a great deal of challenges in understanding the high-frequency, small-scale dynamics of turbulent fluctuations in the solar wind plasma.


2015 ◽  
Vol 766 ◽  
pp. 326-336 ◽  
Author(s):  
Tore Magnus A. Taklo ◽  
Karsten Trulsen ◽  
Odin Gramstad ◽  
Harald E. Krogstad ◽  
Atle Jensen

AbstractWe report laboratory experiments and numerical simulations of the Zakharov equation, designed to have sufficient resolution in space and time to measure the dispersion relation for random surface gravity waves. The experiments and simulations are carried out for a JONSWAP spectrum and Gaussian spectra of various bandwidths on deep water. It is found that the measured dispersion relation deviates from the linear dispersion relation above the spectral peak when the bandwidth is sufficiently narrow.


2017 ◽  
Vol 31 (05) ◽  
pp. 1750045
Author(s):  
Yizhe Yuan ◽  
Xiaoyong Guo ◽  
Liqun An ◽  
Wen Xu

We present a theoretical study on graphene-semiconductor planar structures. The frequency of the photonic modes in the structure, which can be efficiently tuned via varying the sample parameters, is within the terahertz (THz) bandwidth. Furthermore, it is found that a roughly linear dispersion relation can be obtained for photonic modes in the THz region. Hence, the proposed graphene-semiconductor planar structures can be served as THz waveguide with desirable transmission characteristics.


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