Interaction of relativistic electron beam with large‐amplitude electromagnetic wave in a uniform magnetic field

1985 ◽  
Vol 58 (9) ◽  
pp. 3646-3648 ◽  
Author(s):  
S. P. Kuo ◽  
G. Schmidt
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Electromagnetic Wave ◽  
Relativistic Electron ◽  
Large Amplitude ◽  
Uniform Magnetic Field ◽  
Relativistic Electron Beam

Electron cyclotron masing and the force due to net stimulated bremsstrahlung in an electron cyclotron maser using a dilute non-relativistic electron beam

1988 ◽  
Vol 39 (2) ◽  
pp. 229-239 ◽  
Author(s):  
S. H. Kim
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Electromagnetic Wave ◽  
Relativistic Electron ◽  
Uniform Magnetic Field ◽  
Relativistic Electron Beam ◽  
Ponderomotive Force ◽  
Electron Cyclotron ◽  
Stimulated Emission ◽  
Cyclotron Maser

The amplification of an electromagnetic wave by net stimulated bremsstrahlung (the emission by stimulated bremsstrahlung minus the absorption by inverse bremsstrahlung) injected into a non-relativistic dilute electron beam travelling in a uniform magnetic field is considered. The d.c. ponderomotive force by net stimulated emission is calculated by using quantum kinetics. From the calculated ponderomotive force, the amplification of the intensity of the electromagnetic wave by the net stimulated bremsstrahlung is derived as a function of the relevant parameters of the electromagnetic wave and the electron beam. It is found that masing is possible when the perpendicular temperature of the electron beam is greater than its parallel temperature. It is shown that the efficiency of a practical gyrotron cannot be explained by the phase-bunching concept, and that simulated bremsstrahlung has nothing to do with any phase bunching.

Fast-wave interaction with a relativistic electron beam

1974 ◽  
Vol 11 (2) ◽  
pp. 299-309 ◽  
Author(s):  
P. Sarangle
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Electron Beam ◽  
Relativistic Electron ◽  
Microwave Radiation ◽  
Relativistic Electron Beam ◽  
Parametric Instability ◽  
Travelling Wave ◽  
Fast Wave ◽  
Coupled Modes

The excitation of a relativistic electron beam, by means of a fast waveguide structure, is examined. Here the beam is injected into a modified waveguide, and interacts with the modes of the guide in such a way as to transform some of its energy into microwave radiation. This microwave generation device, called the Ubitron, is based upon a fast-wave excitation of a magnetically modulated relativistic electron beam. The beam is modulated by injecting it into a small spatially periodic magnetic field region within the guide. Analysis of this interaction shows that the slow space charge beam mode couples actively to the fast transverse electric guide mode. The result is parametric instability of the coupled modes. Synchronism between the doppler-shifted transverse travelling wave and the undulating electron beam results in a transfer of energy from the beam to the transverse field. The parametrically growing field can be a source of microwave radiation. The period magnetic field, together with the beam density, provide the coupling media between the unstable waves. The growth rate of the instability is shown to depend, in a nonlinear manner, on the product of the beam plasma frequency and the strength of the applied rippled magnetic field. The growth rate is obtained as a function of the system parameters.

scholarly journals HIGH-CURRENT RELATIVISTIC ELECTRON BEAM FOCUSING IN PLASMA

2021 ◽  
pp. 30-34
Author(s):  
О.V. Manuilenko ◽  
A.V. Pashchenko ◽  
V.G. Svichensky ◽  
B.V. Zajtsev
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
External Magnetic Field ◽  
Relativistic Electron ◽  
Relativistic Electron Beam ◽  
Beam Current ◽  
High Current ◽  
Plasma Parameters ◽  
Beam Focusing ◽  
Envelope Equation

The analysis of the envelope equation for high-current relativistic electron beam propagation in plasma in an external uniform magnetic field is presented. The envelope equation is obtained in a Hamiltonian form with an effective potential, which depends from electron beam and plasma parameters, and external magnetic field. Hamiltonian aproach allows fully analyze the behavior of the beam envelope as a function of the beam current, beam energy, plasma density and conductivity, as well as on the external magnetic field and the initial beam angular momentum.

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