Lawrence Berkeley National Laboratory

We apply a recently developed Vlasov solver to the study of themicrobunching instability generated by shot noise in the beamdelivery systems of x-ray Free Electron Lasers (FELs). We discusstwo lattices presently under consideration for the FEL FERMI project at Elettra and show that at least one of the two lattices appears capable of delivering a beam with the desired quality in the longitudinal phase space.