• K. Honkavaara, B. Faatz, J. Feldhaus, S. Schreiber, R. Treusch
  DESY, Hamburg
• J. Roßbach
  Uni HH, Hamburg

The free-electron laser user facility FLASH at DESY, Germany has been upgraded. The upgrade started in autumn 2009 after almost 2 years of a very successful second user period. The beam energy is increased to 1.2 GeV by installing a 7th superconducting accelerating module. The new module is a prototype for the European XFEL. Among many other upgrades, 3rd harmonic superconducting RF cavities are installed in the injector. The main purpose is to flatten and - to a certain extend - to shape the longitudinal electron beam phase space improving the dynamics behavior of the beam. The seeding experiment sFLASH is being commissioned, an important step forward to establish seeded FEL radiation for user experiments. After the ongoing commissioning, the 3rd user period will start this summer. In many aspects FLASH will be an FEL with a new quality of performance: a wavelength approaching the carbon edge and the water window, tunable pulse width, and with thousands of pulses per second. This report summarizes the recently finished upgrade of FLASH and reports on the results of the ongoing commissioning and the expected performance as a free electron laser user facility.

Slides

• G. Penco, E. Allaria, L. Badano, S. Bassanese, M. Bossi, D. Castronovo, G. Ciani, S. Cleva, P. Craievich, M.B. Danailov, R. De Monte, G. De Ninno, A.A. Demidovich, S. Di Mitri, M. Ferianis, O. Ferrando, S. Ferry, L. Froehlich, G. Gaio, R. Ivanov, M. Lonza, A.A. Lutman, S.V. Milton, M. Petronio, M. Predonzani, F. Rossi, L. Rumiz, C. Scafuri, G. Scalamera, P. Sigalotti, S. Spampinati, C. Spezzani, M. Trovò, M. Veronese
  ELETTRA, Basovizza
• L. Pavlovič
  Uni LJ, Ljubljana

The FERMI@Elettra injector, comprised of a high-gradient, s-band, photo-cathode rf gun, the PC gun driven laser, the first two accelerating sections, controls, and suite of diagnostics has been commissioned in 2009. The electron beam has been characterized in terms of charge, energy, energy spread and transverse emittance, and results are provided in this paper. In early 2010 linac commissioning up to 250MeV continued, and by using the RF deflecting cavity, the slice parameters of the beam have been measured. Moreover, studies on the laser pulse shaping and the relative optimization of the longitudinal ramp profile required by the nominal bunch configuration are presented in this paper.

Slides

• E. Chiadroni, F. A. Anelli, M. Bellaveglia, M. Boscolo, M. Castellano, L. Cultrera, G. Di Pirro, M. Ferrario, L. Ficcadenti, D. Filippetto, S. Fioravanti, G. Gatti, E. Pace, R.S. Sorchetti, C. Vaccarezza
  INFN/LNF, Frascati (Roma)
• A. Bacci, A.R. Rossi
  Istituto Nazionale di Fisica Nucleare, Milano
• P. Calvani, S. Lupi, D. Nicoletti
  Università di Roma I La Sapienza, Roma
• L. Catani, B. Marchetti
  INFN-Roma II, Roma
• A. Cianchi
  Università di Roma II Tor Vergata, Roma
• O. Limaj
  University of Rome La Sapienza, Rome
• A. Mostacci
  Rome University La Sapienza, Roma
• C. Ronsivalle
  ENEA C.R. Frascati, Frascati (Roma)

The region of the spectrum from 0.3 to 5 THz is of great interest for several experiments in different areas of research. A THz radiation source can be produced at SPARC as coherent transition radiation emitted by either a compressed or longitudinally modulated beam intercepting a metal foil placed at 45° with respect to the beam propagation. Results on the characterization of the THz source at SPARC are described in the paper.

Slides