Free-Electron
Lasers as high-brilliance radiation sources, rely on a high quality
of the electron beam driving the FEL process. The amount of energy,
transferred from the electrons to the radiation field, and thus the
efficiency of the FEL depends on the provided beam parameters. The presentation
discusses the impact of various beam parameter and how current designs
of FEL injector try to accomplish the demands on the beam quality for
reaching saturation.