VISIONS OF SCIENCE WITH X-RAY FREE ELECTRON LASERS 
H.A. Dürr

Bessy GmbH, 12489 Berlin, Germany

BESSY recently proposed the construction of a soft x-ray Free Electron Laser (FEL) as a revolutionary new source for the spectral range covering VUV radiation to soft x-rays (20 eV to 1keV). This new source promisses fs pulses which have orders of magnitude higher output power as compared to present day VUV and soft x-ray synchrotron sources. Seeding of the FEL permits a substantional reduction of the pulse length reaching values down to 20 fs or below. This FEL is expected to provide a foundation of a completely new field of scientific research as will be described in this talk through selected examples. The synergy with other planned x-ray FEL sources will be discussed.