Relativistic diamagnetic equilibrium of a thin-walled annular electron beam in an external magnetic field

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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Nonlinear dynamics and chaotization of oscillations of a virtual cathode in an annular electron beam in a uniform external magnetic field

Plasma Physics Reports ◽

10.1134/s1063780x09080029 ◽

2009 ◽

Vol 35 (8) ◽

pp. 628-642 ◽

Cited By ~ 12

Author(s):

S. A. Kurkin ◽

A. A. Koronovski ◽

A. E. Hramov

Keyword(s):

Magnetic Field ◽

Nonlinear Dynamics ◽

Electron Beam ◽

External Magnetic Field ◽

Virtual Cathode ◽

Annular Electron Beam ◽

Uniform External Magnetic Field

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Whistler emission through transition radiation by a modulated electron beam spiralling in a magnetoplasma

Journal of Plasma Physics ◽

10.1017/s0022377899008247 ◽

2000 ◽

Vol 63 (3) ◽

pp. 285-295 ◽

Cited By ~ 8

Author(s):

M. STARODUBTSEV ◽

C. KRAFFT

Keyword(s):

Magnetic Field ◽

Electron Beam ◽

External Magnetic Field ◽

Transition Radiation ◽

Physical Processes ◽

Phase Velocities ◽

Electric Dipoles ◽

Wave Emission ◽

Loop Antennas

Transition radiation from the zone of injection of a modulated electron beam spiralling into a magnetoplasma has been identified as whistler waves propagating quasiparallel to the external magnetic field. The characteristics of the radiation are similar to the emission by localized sources, such as loop antennas and electric dipoles: resonance-cone structures at low plasma densities and energy flow along the external magnetic field at higher densities, with a diverging radiation pattern and with whistler phase velocities inversely proportional to the plasma frequency. These studies should contribute to a wider understanding of the physical processes connected with the injection of charges in a magnetoplasma – either from a gun on board a spacecraft or in a plasma chamber – and thus allow the determination of appropriate radiator characteristics in order to control, to some extent, plasma perturbations and wave emission in the region of the injector.

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