Observation of self-amplified spontaneous emission in the wavelength range from 80 to 180 nm at the TESLA test facility FEL at DESY

The first observation of Self-Amplified Spontaneous Emission (SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet range between 80 and 180 nm wavelength is presented. The observed FEL gain (typically above 1000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width and intensity fluctuations are discussed. Some accelerator issues are covered, and the future plans for the TESLA Test Facility (TTF) FEL are mentioned.