Author: Di Mitri, S.
Paper Title Page
TUPEA010 FERMI Seeded FEL Progress Report 1182
  • M. Svandrlik, E. Allaria, F. Bencivenga, C. Callegari, F. Capotondi, D. Castronovo, P. Cinquegrana, P. Craievich, I. Cudin, G. D'Auria, M. Dal Forno, M.B. Danailov, R. De Monte, G. De Ninno, A.A. Demidovich, S. Di Mitri, B. Diviacco, A. Fabris, R. Fabris, W.M. Fawley, M. Ferianis, E. Ferrari, P. Finetti, L. Fröhlich, P. Furlan Radivo, G. Gaio, L. Giannessi, M. Kiskinova, G.L. Loda, M. Lonza, B. Mahieu, N. Mahne, C. Masciovecchio, F. Parmigiani, G. Penco, O. Plekan, M. Predonzani, E. Principi, L. Raimondi, F. Rossi, L. Rumiz, C. Scafuri, C. Serpico, P. Sigalotti, S. Spampinati, C. Spezzani, L. Sturari, C. Svetina, M. Trovò, A. Vascotto, M. Veronese, R. Visintini, D. Zangrando, M. Zangrando
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • P. Craievich
    PSI, Villigen PSI, Switzerland
  • B. Mahieu
    CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
  Funding: Work supported in part by the Italian Ministry of University and Research under grants FIRB-RBAP045JF2 and FIRB-RBAP06AWK3
FERMI, the seeded Free Electron Laser located at the Elettra laboratory in Trieste, Italy, welcomed in December 2012 the first external users on the FEL-1 line. This line is based on a single stage of High Gain Harmonic Generation (HGHG), seeded by a UV laser, and covers wavelengths between 80 and 20 nm. The photon energy reached more than 300 μJ. The second FEL line, FEL-2, covering the lower wavelength range between 20 and 4 nm thanks to a double stage cascaded HGHG scheme, has generated its first coherent photons in October 2012. This is the first experimental demonstration of a seeded free electron laser configured as a two stages cascade operating in the "fresh bunch injection” mode, where the second stage is seeded by the light produced by the first stage. This paper describes the status of the operation and user experiments with FEL-1 and reports about the progress in the commissioning of FEL-2.
TUPEA011 Double Stage Seeded FEL with Fresh Bunch Injection Technique at FERMI@Elettra 1185
  • S. Di Mitri, E. Allaria, D. Castronovo, P. Cinquegrana, P. Craievich, G. D'Auria, M.B. Danailov, G. De Ninno, A.A. Demidovich, B. Diviacco, W.M. Fawley, M. Ferianis, E. Ferrari, L. Fröhlich, G. Gaio, L. Giannessi, R. Ivanov, B. Mahieu, N. Mahne, I. Nikolov, F. Parmigiani, G. Penco, L. Raimondi, C. Serpico, P. Sigalotti, S. Spampinati, C. Spezzani, M. Svandrlik, C. Svetina, M. Trovò, A. Vascotto, M. Veronese, D. Zangrando, M. Zangrando
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • D. Gauthier
    University of Nova Gorica, Nova Gorica, Slovenia
  During the month of October 2012 the commissioning of the light source FEL-2 at FERMI was successfully concluded. Fermi FEL-2 is the first seeded FEL operating with a double stage cascade in the "fresh bunch injection" mode*. The two stages are two high gain harmonic generation FELs where the first stage is seeded by the 3rd harmonic of a Ti:Sa laser system, which is up converted to the 4th-12th harmonic. The output of the first stage is then used to seed the second stage. A final wavelength of 10.8 nm was obtained as the 24th harmonic of the seed wavelength at the end of the two frequency conversion processes, demonstrating that the FEL is capable of producing single mode narrow bandwidth pulses with an energy of several tens ofμjoules. We report on the experimental characterisation of the FEL performances in this configuration.
* I. Ben-Zvi, K. M. Yang, L. H. Yu, ”The ”fresh-bunch” technique in FELs”, NIM A 318 (1992), p 726-729
THPFI010 High Energy RF Deflectors for the FERMI@Elettra project 3309
  • M. Dal Forno, S. Biedron, D. Castronovo, P. Craievich, S. Di Mitri, D. La Civita, G. Penco, M. Petronio, F. Pradal, L. Rumiz, L. Sturari, D. Wang, D. Zangrando
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • P. Craievich
    PSI, Villigen PSI, Switzerland
  • M. Dal Forno, M. Petronio, R. Vescovo
    University of Trieste, Trieste, Italy
  • N. Faure
  Measuring and controlling the longitudinal phase space and the time-slice emittance of the electron bunch at 1.2 GeV entering in the undulator beam-lines, is crucial to obtain high FEL performances. In the FERMI@Elettra machine, two RF deflecting cavities have been installed at the end of the linac, in order to stretch the electron bunch horizontally and vertically, respectively. The two cavities are individually powered by the same klystron and a switch system is used to choose the deflection plane. This paper reports the RF measurements carried out during the acceptance test, the RF conditioning including the breakdown rate measurements. Finally, the commissioning with electron beam of the deflecting structure and a comparison of the measured electron bunch length evaluated by using the two deflectors are also reported.