• S. Di Mitri, E. Allaria, R. Appio, L. Badano, D. Castronovo, M. Cornacchia, P. Craievich, S. Ferry, L. Froehlich, S.V. Milton, G. Penco, C. Scafuri, C. Spezzani, M. Trovò, M. Veronese
  ELETTRA, Basovizza
• R. Bartolini
  Diamond, Oxfordshire
• G. De Ninno, S. Spampinati
  University of Nova Gorica, Nova Gorica
• P. Evtushenko
  JLAB, Newport News, Virginia
• W.M. Fawley
  LBNL, Berkeley, California
• L. Giannessi
  ENEA C.R. Frascati, Frascati (Roma)
• A.A. Lutman
  DEEI, Trieste
• M. Sjöström
  MAX-lab, Lund

Some experiences have recently been collected from the FERMI@elettra Free Electron Laser first bunch compressor area. This includes a magnetic compressor, diagnostics for the characterization of the longitudinal and transverse phase space and suitable optics for matching to the downstream part of the linac. We report on the beam dynamics investigations in comparison with the modeling as well as the high level software control that has allowed this experience.

• L. Froehlich, G. Cautero, D. Giuressi, R.H. Menk
  ELETTRA, Basovizza
• D. Di Giovenale
  INFN-Roma II, Roma

FERMI@Elettra is a linac-driven free-electron laser currently under construction at the synchrotron radiation facility Elettra in Trieste, Italy. In order to prevent damage to accelerator components, an active machine protection system (MPS) monitors beam losses along the linac and, if necessary, inhibits the beam production in the injector. Special attention is paid to the protection of permanent undulator magnets from demagnetization by the excessive absorption of radiation. This paper discusses the system architecture and gives an overview of the major diagnostic subsystems: A beam loss position monitor based on the detection of Cherenkov light induced in quartz fibers, an array of discrete ionization chambers, and a system for differential charge loss measurements. The dose deposition in the undulator magnets will be monitored with electronic RadFET dosimeters; first details of the readout system are presented.