High Energy RF Deflectors for the FERMI@Elettra project

Measuring and controlling the longitudinal phase space and the time-slice emittance of the electron bunchentering at 1.2 GeV in the undulator beam-lines, are crucial to obtain high FEL performances. In the FERMI@Elettra machine, two RF deflecting cavities have been installed at the end of the linac, in order to stretch the electron bunch horizontallyand vertically, respectively. The two cavities are individually powered by the same klystronand a switch system is used to choose the deflection plane. This paper reports the RF measurements carried out during the acceptance testand the RF conditioning including the breakdown rate measurements.