Influence of finite radial geometry on the growth rate of ion-channel free electron laser
Abstract
The influence of finite radial geometry on the instability of a tenuous relativistic electron beam propagating in an ion-channel in a waveguide is investigated. The instability analysis is based on the linearized Vlasov-Maxwell equations for the perturbation about a self-consistent beam equilibrium. With the help of characteristic method the dispersion relation for the TE-mode is derived and analyzed through the numerical solutions. It is found that the positioning of the beam radius Rb relative to the waveguide radius Rc, and the ion-channel frequency can have a large influence on the maximum growth rate and corresponding wave number.
- Publication:
-
Physics of Plasmas
- Pub Date:
- November 2013
- DOI:
- Bibcode:
- 2013PhPl...20k3114B
- Keywords:
-
- free electron lasers;
- laser beams;
- laser modes;
- laser stability;
- Maxwell equations;
- numerical analysis;
- relativistic electron beams;
- Vlasov equation;
- waveguide lasers;
- 41.60.Cr;
- 42.60.Lh;
- 42.60.Jf;
- Free-electron lasers;
- Efficiency stability gain and other operational parameters;
- Beam characteristics: profile intensity and power;
- spatial pattern formation