High power femtosecond pulses from an X-ray SASE-FEL

We discuss how to use the large-gain bandwidth of an X-ray SASE-FEL to produce femtosecond long pulses by chirping and compressing the output FEL radiation. We consider the power Icl cl. spectral width, and intensity fluctuations of the compressed X-ray pulses, compared to the case with no compression. (C) 2000 Elsevier Science B.V. All rights reserved.