FIRST OPERATION OF THE ELECTRO OPTICAL SAMPLING DIAGNOSTICS OF THE FERMI@ELETTRA FEL

The FERMI@Elettra seeded FEL has demanding specifications in terms of longitudinal properties of the electron beam. Several diagnostics are installed along the linac. At the entrance of the FEL1 undulator chain an electro optical sampling (EOS) station based on the spatial encoding scheme is installed. The EOS provides both time jitter and longitudinal profile measurements in a non-destructive way. The layout of this system is described and the first operational measurement results obtained are reported. The paper includes also the capability of this diagnostics to perform the temporal coarse alignment of the seed laser to the electron beam. Finally a discussion on the future developments foreseen for this system is given.