P. Chaix et al., CHAOS AND THE TAMING OF FREE-ELECTRON LASER SPECTRAL DYNAMICS, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 331(1-3), 1993, pp. 406-410
We provide a semi-quantitative analysis of the electron phase space in
a uniform wiggler with a broad spectrum laser field, and in an optimi
zed two frequency wiggler with a monochromatic laser field. We show th
at the two problems are formally equivalent, and for the first one we
reach a theoretical interpretation and an estimate for the universal r
atio between extracted efficiency and relative spectral width.