Modes for gain maximization of the free electron laser in the lowgain, smallsignal regime
Abstract
We calculate the maximum gain obtainable from a uniformwiggler FEL in the smallsignal, smallgain regime, taking diffraction into account. The gain and the electron energy detuning at which it is maximal are calculated as a function of the electronbeam Fresnel number F. Gain maximization requires appropriate choice of a resonator. The mirrors need to have larger curvature and aberrations when F is small. In an appendix we generalize our gain formula to a nonuniform wiggler.
 Publication:

Nuclear Instruments and Methods in Physics Research A
 Pub Date:
 September 1986
 DOI:
 10.1016/01689002(86)909198
 Bibcode:
 1986NIMPA.250..418M