Coherent and incoherent radiation from free electron lasers with an axial guide field
Abstract
The spontaneous and induced emission from a free electron laser is treated for the case in which an axial magnetic field is imposed in addition to the helical, axially periodic wiggler magnetic field. The classes of possible singleparticle trajectories in this configuration are discussed, and the results are applied to a calculation of the incoherent radiation from a beam of relativistic electrons in the system. The coherent radiation is treated by solving the VlasovMaxwell equations for the linear gain in the tenuous beam limit, where the beam plasma frequency is much less than the radiation frequency and selffield effects can be ignored.
 Publication:

Naval Research Lab. Report
 Pub Date:
 October 1981
 Bibcode:
 1981nrl..reptT....F
 Keywords:

 Coherent Radiation;
 Free Electron Lasers;
 High Power Lasers;
 Incoherent Scattering;
 Waveguides;
 Magnetic Field Configurations;
 Maxwell Equation;
 Microwaves;
 Particle Trajectories;
 Vlasov Equations;
 Wiggler Magnets;
 Lasers and Masers