Statistical properties of the radiation from VUV-FEL at DESY (Femtosecond mode of operation)

Present bunch compression scheme at the VUV FEL at DESY is essentially nonlinear and naturally results in the formation of a short, high-current leading peak (spike) in the density distribution that produces FEL radiation. The main feature of the considered mode of operation is the production of short, down to 20 fs radiation pulses with GW-level peak power and contrast of 80%.