Nonlinear analysis of the free electron lasers utilizing a linear wiggler field
Abstract
A one dimensional steady state (FEL) amplifier, utilizing a linearly polarized magnetic wiggler field, is analyzed in the linear and nonlinear operating regimes. Our formulation of the FEL problem includes all the efficiency enhancements schemes, electron beam thermal effects and collective effects, i.e., space charge waves. The axial electron velocity, due to a linearly polarized wiggler field, has a spatially oscillatory component. It is shown that this axial velocity jiggle does not result in phase incoherence between the electrons and the ponderomotive wave. The axial velocity jiggle is explicitly incorporated into our analytical model. The inclusion of the electron jiggle velocity is shown to have a quantitative effect on the nonlinear wave particle dynamics. The electron trapping potential associated with the ponderomotive wave is also derived. Finally, a number of numerical examples pertinent to the design of a 10 micron FEL amplifier are presented.
 Publication:

Naval Research Lab. Report
 Pub Date:
 October 1981
 Bibcode:
 1981nrl..reptV....T
 Keywords:

 Electron Accelerators;
 Free Electrons;
 Magnetic Pumping;
 Electron Beams;
 Linear Systems;
 Nonlinear Systems;
 Thermodynamic Properties;
 Lasers and Masers