Erratum to: Effects of electron beam velocity spread, temperature, and self-fields on dispersion relation and growth rate in a Cherenkov radiation

This paper gives an extensive analytical and numerical characterization of the growth-rate curves (imaginary frequency versus wavenumber) derived from the free electron laser dispersion relation for a warm relativistic electron beam propagating through a constant-amplitude helical magnetic wiggler field. The electron beam is treated as infinite in transverse extent. A detailed mathematical analysis is given of the exact dispersion relation and its Compton approximation for the case of a water-bag equilibrium distribution function (uniform distribution in axial momentum pz). Applicability of the water-bag results to the case of a Gaussian equilibrium distribution in pz is tested numerically. One result of the water-bag analysis is a set of validity conditions for the Compton approximation. Numerical and analytical results indicate that these conditions are applicable to the Gaussian case far outside the parameter range where the individual water-bag and corresponding Gaussian growth rate curves agree.

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Plasma maser theory of the extraordinary mode in the presence of Langmuir turbulence

Journal of Plasma Physics ◽

10.1017/s0022377800016159 ◽

1991 ◽

Vol 46 (2) ◽

pp. 331-346 ◽

Cited By ~ 11

Author(s):

S. N. Sarma ◽

K. K. Sarma ◽

M. Nambu

Keyword(s):

Growth Rate ◽

Electron Beam ◽

Dispersion Relation ◽

Space Plasma ◽

Conversion Process ◽

Nonlinear Dispersion ◽

Langmuir Turbulence ◽

Nonlinear Dispersion Relation ◽

Maser Effect ◽

Scope Of Application

The emission of extraordinary mode radiation in a plasma with Langmuir turbulence driven by an electron beam is considered. The process of emission considered in this paper is the plasma maser effect, which is essentially an energy up-conversion process. The energy necessary for the growth of the extraordinary mode is derived from the Langmuir turbulence. The nonlinear dispersion relation of the extraordinary mode in the presence of Langmuir turbulence is obtained and its growth rate calculated. The scope of application of the results to space-plasma observation is then stressed.

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Theory of terahertz Smith-Purcell radiation from a cylindrical grating

Papers in Physics ◽

10.4279/pip.110007 ◽

2019 ◽

Vol 11 ◽

pp. 110007

Author(s):

Z. Rezaei ◽

B. Farokhi

Keyword(s):

Magnetic Field ◽

Growth Rate ◽

Electron Beam ◽

Dispersion Relation ◽

External Magnetic Field ◽

Free Electron ◽

Free Electron Lasers ◽

Annular Electron Beam ◽

High Efficient ◽

Beam Thickness

An analysis of an annular electron beam propagating along a cylindrical grating with external magnetic field Bo is presented. The grating comprises a dielectric in its slots. The dispersion relation of the modes is derived. The results demonstrate that the dielectric shifts the frequencies of the system modes to smaller values. The growth rates of the modes which are in phase with the beam are also considered. It is found that the decline in the growth rate is brought about by the dielectric. In addition, increasing the thickness of the dielectric and decreasing the height of the slots cause it to rise. The effect of beam thickness on growth rate is considered too. This is shown to increase and then fall as beam thickness increases. These results show that utilizing cylindrical grating loaded with dielectric has a promising effect on developing new kinds of compact high-efficient THz free-electron lasers based on Smith–Purcell radiation. Edited by: A. B. Márquez

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Electron Beam Velocity Spread Effect on a Clinotron Operation

2018 IEEE 17th International Conference on Mathematical Methods in Electromagnetic Theory (MMET) ◽

10.1109/mmet.2018.8460245 ◽

2018 ◽

Author(s):

Yurii Kovshov ◽

Sergey Ponomarenko ◽

Sergey Kishko ◽

Alexandr Likhachev ◽

Alexandr Danik ◽

...

Keyword(s):

Electron Beam ◽

Velocity Spread ◽

Beam Velocity

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Enhancement in the electromagnetic beam-plasma instability due to ion streaming

Journal of Plasma Physics ◽

10.1017/s0022377811000559 ◽

2011 ◽

Vol 78 (2) ◽

pp. 181-187 ◽

Cited By ~ 10

Author(s):

NITIN SHUKLA ◽

A. STOCKEM ◽

F. FIÚZA ◽

L. O. SILVA

Keyword(s):

Magnetic Field ◽

Growth Rate ◽

Dispersion Relation ◽

Theoretical Analysis ◽

Velocity Spread ◽

Two Dimensional ◽

Mass Ratio ◽

Particle In Cell ◽

Anisotropic Temperature ◽

Beam Plasma Instability

AbstractWe investigate the Weibel instability in counter-propagating electron–ion plasmas with focus on the ion contribution, considering a realistic mass ratio. A generalized dispersion relation is derived from the relativistic theory by assuming an initially anisotropic temperature, which is represented by a waterbag distribution in momentum space, which shows an enhanced growth rate due to ion response. Two-dimensional particle-in-cell simulations support the theoretical analysis, showing a further amplification of magnetic field on ion time scale. The effect of an initial anisotropic temperature is investigated showing that the growth rate is monotonously decreased if the transverse spread is increased. Nevertheless, the presence of ions generates that the instability can develop for significantly higher electron temperatures. Suppression of oblique mode is also explored by introducing a parallel velocity spread.

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Excitation of whistlers and quasi-static modes by an annular electron beam in a plasma cylinder

Journal of Plasma Physics ◽

10.1017/s0022377800026726 ◽

1988 ◽

Vol 39 (3) ◽

pp. 407-411 ◽

Cited By ~ 2

Author(s):

I. Talukdar ◽

V. K. Jain

Keyword(s):

Growth Rate ◽

Electron Beam ◽

Local Theory ◽

Beam Radius ◽

Plasma Cylinder ◽

Static Mode ◽

Weak Beam ◽

Annular Electron Beam ◽

Beam Velocity ◽

Slow Cyclotron

A non-local theory of whistler and quasi-static mode excitation by an annular electron beam in a plasma cylinder is presented. Čerenkov and slow-cyclotron interaction are considered in the weak-beam approximation. The growth rate is found to be quite sensitive to the beam radius except in the case of slow-cyclotron interaction of quasi-static modes. The growth rate varies significantly with beam velocity in the case of Čerenkov interaction of quasi-static modes, but in other cases it is rather insensitive to the beam velocity.

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