On the collective variables description of a high gain free electron laser
Abstract
It has been shown that the linearized equations describing the motion of electrons and the development of the radiation field in a free electron laser (FEL) can be conveniently studied using the collective variable approach. The advantage of this method is that the equations are greatly simplified, while the variables remain physically easily recognizable quantities. In this report two methods are used to construct the collective variables and deduce their linearized equations of motion: the VlasovMaxwell approach, where the distribution function f and the radiation field are linearized about equilibrium, and the many particle approach in which the linearization is performed for the dynamical variables of all the particles and the radiation field. In both cases the transverse effects and the dependence of the radiation field on spatial coordinates are included. The two approaches are equivalent.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 June 1987
 Bibcode:
 1987STIN...8811108G
 Keywords:

 Electron Beams;
 Equations Of Motion;
 Free Electron Lasers;
 Maxwell Equation;
 Distribution Functions;
 Electric Fields;
 High Gain;
 Wiggler Magnets;
 Lasers and Masers