• E. Allaria
  ELETTRA, Basovizza
• X. Dao
  SLAC, Menlo Park, California
• G. De Ninno
  University of Nova Gorica, Nova Gorica

Recently, the second FEL line of the FERMI FEL has been modified in order to extend its tuning range down to 3 nm. In order to reach such a short wavelength starting from the UV seed laser the FERMI FEL-2 system relies on a double cascade of high gain harmonic generation. In this work we study the possibility of using the present FEL-2 layout with minor modifications to demonstrate the feasibility of the recently proposed echo-enabled harmonic generation (EEHG). The final aim is to cover the expected spectral range of FEL-2 with a single cascade. The performance of the EEHG in FERMI FEL-2 is estimated by means of start-to-end FEL simulations.

• E. Allaria
  ELETTRA, Basovizza
• G. De Ninno
  University of Nova Gorica, Nova Gorica
• W.M. Fawley
  LBNL, Berkeley, California

The second stage of the FERMI FEL, named FEL-2, is based on the principle of high-gain harmonic generation and relies on a double-seeded cascade. Recent developments stimulated a revision of the original setup, which was designed to cover the spectral range between 40 and 10 nm. According to the numerical simulations we present here, the nominal (expected) electron-beam performance allows to extend the FEL spectral range down to 3 nm. A significant amount of power can be also expected at about 1 nm. We also show that the proposed setup is flexible enough for exploiting future developments of new seed sources, like, e.g., high harmonic generation in gases.

• G. De Ninno
  University of Nova Gorica, Nova Gorica
• E. Allaria, M. Cornacchia, G. De Ninno, S. Di Mitri, B. Diviacco, G. Penco, C. Spezzani, M. Trovò
  ELETTRA, Basovizza

The commissioning of the first stage of FERMI@Elettra will start during the summer 2009. During the first year of operation, efforts will concentrate on the optimization of the gun performance, as well as of the electron-beam acceleration and transport through the LINAC. By fall 2010, it is our aim to generate out of the LINAC an electron beam as similar as possible to the one needed for obtaining the nominal (i.e., user-required) FEL performance [see, e.g., S. Di Mitri et al., this Conference]. Such a beam will be then injected into the undulator chain and used to get the first FEL light. In this paper, we present our strategy for the commissioning of the FEL process, both in SASE and seeded configurations. On the basis of start-to-end simulations, we also discuss the expected FEL performance for day-one operation.