Influence of transverse dc self‐fields of the electron beam on the dispersion relation in a free‐electron laser with an axial magnetic field

1989 ◽  
Vol 66 (8) ◽  
pp. 3463-3466 ◽  
Author(s):  
Shi‐chang Zhang ◽  
Zhong Zhang
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Dispersion Relation ◽  
Free Electron ◽  
Free Electron Laser ◽  
Axial Magnetic Field

scholarly journals Compton and Raman free electron laser stability properties for a cold electron beam propagating through a helical magnetic wiggler

1985 ◽  
Vol 33 (3) ◽  
pp. 387-423 ◽  
Author(s):  
John A. Davies ◽  
Ronald C. Davidson ◽  
George L. Johnston
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Dispersion Relation ◽  
Free Electron ◽  
Free Electron Laser ◽  
Relativistic Electron Beam ◽  
Cold Electron ◽  
Wiggler Magnetic Field ◽  
Laser Stability

This paper gives an extensive characterization of the range of validity of the Compton and Raman approximations to the exact free electron laser dispersion relation for a cold, relativistic electron beam propagating through a constantamplitude helical wiggler magnetic field. The electron beam is treated as infinite in transverse extent. Specific properties of the exact and approximate dispersion relations are investigated analytically and numerically. In particular, a detailed numerical analysis is carried out to determine the range of validity of the Compton approximation.

Dispersion relation and growth rate in a free-electron laser with a background plasma

2015 ◽  
Vol 81 (3) ◽  
Author(s):  
T. Mohsenpour ◽  
B. Maraghechi
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Dispersion Relation ◽  
Plasma Density ◽  
Free Electron ◽  
Free Electron Laser ◽  
Axial Magnetic Field ◽  
Background Plasma ◽  
Positive Energy ◽  
Induced Velocity

The method of perturbation has been applied to derive a general dispersion relation for a free-electron laser (FEL) with background plasma and helical wiggler in the presence of an axial magnetic field. This dispersion relation is solved numerically to find unstable interactions among all of the wave modes. Numerical calculations show that new coupling between the left wave and positive-energy space-charge of electron beam are found when wiggler induced velocity is large. This coupling does not change with increasing the plasma density. The growth rate of FEL is changed with increasing the plasma density and the normalized axial magnetic field.

Sign in / Sign up

Export Citation Format

Share Document