Research on a twostage free electron laser oscillator
Abstract
The research involved the theoretical and numerical analysis of the physics of free electron lasers using relativistic particle beams. The major emphasis of the research was to obtain design criteria for the development of a twostage FEL oscillator operating in the trapped particle mode. The present work was centered on the development of a fully relativistic, nonlinear analysis of the spatial and temporal evolution of multiple modes within a free electron laser oscillator and of a large amplitude, nonlinearly saturated state characteristic of trapped particle mode operation. The equations solved are the Maxwell equations of electrodynamics coupled with the collisionless Boltzmann equation that describes collisionless particles under influence of the electromagnetic fields. The electromagnetic fields include the radiation fields from the FEL and the selfelectric fields from the longitudinal potential due to the space charge, i.e., the dominant component of the interparticle Coulomb forces. The particle dynamics transverse to the magnetic axis are included, but gradients in the radiation fields are ignored. The electron beam equilibrium is assumed to be spatially uniform and temporally stationary. Justification and probable impact of further approximations are discussed in the technical section of this report. The approximations employed are consistent with the purpose of obtaining experimentally implementable design criteria for the FEL oscillator.
 Publication:

Final Report Berkeley Research Associates
 Pub Date:
 March 1988
 Bibcode:
 1988brai.reptS.....
 Keywords:

 Free Electron Lasers;
 Oscillators;
 Particle Beams;
 Relativistic Particles;
 Trapped Magnetic Fields;
 Trapped Particles;
 Boltzmann Transport Equation;
 Collisionless Plasmas;
 Electrodynamics;
 Electromagnetic Fields;
 Electron Beams;
 Maxwell Equation;
 Numerical Analysis;
 Plasma Equilibrium;
 Probability Theory;
 Space Charge;
 Thermal Radiation;
 Lasers and Masers