A LOW-ENERGY RF DEFLECTOR FOR THE FERMI@ELETTRA PROJECT

A RF deflector is a useful tool to completely characterize the beam phase space by means of measurements of the bunch length and the transverse slice emittance. At FERMI@Elettra, a soft X-ray next-generation light source under development at the Sincrotrone Trieste laboratory in Trieste, Italy, we are installing low-energyand high-energy deflectors. In particular, two deflecting cavities will be positioned at two points in the linac. One will be placed at 1.2 GeV (high energy), just before the FEL process starts; the other at 250 MeV (low energy), after the first bunch compressor (BC1). This paper concerns only the low-energy deflector. The latter was built over the past year in collaboration with the SPARC project teamat INFN-LNFFrascati, Italy and the University of Rome. In this paper we will describe the RF measurements performed to characterize the standing wave cavity before the installation in the FERMI@Elettra linac, and we will compare them with the simulations doneusingthe electromagneticcodeHFSS.