Author: Bencivenga, F.
Paper Title Page
MOD04 Status and Perspectives of the FERMI FEL Facility 1
  • L. Giannessi, E. Allaria, L. Badano, F. Bencivenga, C. Callegari, F. Capotondi, F. Cilento, P. Cinquegrana, M. Coreno, I. Cudin, G. D'Auria, M.B. Danailov, R. De Monte, G. De Ninno, P. Delgiusto, A.A. Demidovich, M. Di Fraia, S. Di Mitri, B. Diviacco, A. Fabris, R. Fabris, W.M. Fawley, M. Ferianis, P. Furlan Radivo, G. Gaio, D. Gauthier, F. Gelmetti, F. Iazzourene, S. Krecic, M. Lonza, N. Mahne, M. Malvestuto, C. Masciovecchio, M. Milloch, N.S. Mirian, F. Parmigiani, G. Penco, A. Perucchi, L. Pivetta, O. Plekan, M. Predonzani, E. Principi, L. Raimondi, P. Rebernik Ribič, F. Rossi, E. Roussel, L. Rumiz, C. Scafuri, C. Serpico, P. Sigalotti, S. Spampinati, C. Spezzani, M. Svandrlik, M. Trovò, A. Vascotto, M. Veronese, R. Visintini, D. Zangrando, M. Zangrando
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  FERMI is the seeded Free Electron Laser (FEL) user facility at the Elettra laboratory in Trieste, operating in the VUV to EUV and soft X-rays spectral range; the radiation produced by the seeded FEL is characterised by a number of desirable properties, such as wavelength stability, low temporal jitter and longitudinal coherence. In this paper, after an overview of the FELs performances, we will present the development plans under consideration for the next 3 to 5 years. These include an upgrade of the LINAC and of the existing FEL lines, the possibility to perform multi-pulse experiments in different configurations and an Echo Enabled Harmonic Generation experiment on FEL-2, the FEL line extending to 4 nm (310 eV).  
Four-Wave Mixing Using Extreme Ultraviolet Transient Gratings at FERMI FEL  
  • F. Bencivenga, F. Capotondi, R. Cucini, L. Foglia, C. Masciovecchio, R. Mincigrucci, E. Pedersoli, E. Principi, A. Simoncig
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  Four-wave mixing (FWM) processes are exploited in the optical domain in a large array of scientific and technological applications. The extension of this approach to the XUV and X-ray range was theoretically conceived,* but not experimentally pursued because of the lack of photon sources with enough brightness and coherence. This situation has changed with the advent of FELs, in particular those stabilized by seeding processes. In this context, the XUV pulses delivered by FERMI have been used to experimentally demonstrate the FWM response stimulated by XUV transient gratings.** More recently the 'twin-seed' double-colour FEL mode of FERMI has been employed in a two-colour XUV FWM experiment.*** These results provide grounds to build up the sophisticated experiments envisioned by theoreticians,* which could provide access to high energy/high-wavevector excitations, with elemental selectivity and nano to atomic spatial resolution. Capabilities that can be exploited in different fields, ranging from thermal transport dynamics in nanoelectronic devices to charge transfer processes in molecules.
* S. Tanaka and S. Mukamel, Phys. Rev. Lett., 2002, 89, 043001
** F. Bencivenga et al., Nature, 2015, 520, 205
*** F. Bencivenga et al., Faraday Discuss., 2014, 171, 487