Author: Ivanov, R.
Paper Title Page
MOOBNO01 First Lasing of FERMI FEL-2 1
 
  • L. Giannessi, E. Allaria, D. Castronovo, P. Cinquegrana, G. D'Auria, M. Dal Forno, M.B. Danailov, G. De Ninno, A.A. Demidovich, S. Di Mitri, B. Diviacco, W.M. Fawley, M. Ferianis, E. Ferrari, L. Fröhlich, G. Gaio, R. Ivanov, B. Mahieu, N. Mahne, I. Nikolov, F. Parmigiani, G. Penco, L. Raimondi, C. Serpico, P. Sigalotti, C. Spezzani, M. Svandrlik, C. Svetina, M. Trovò, M. Veronese, D. Zangrando, M. Zangrando
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • M. Dal Forno
    DEEI, Trieste, Italy
  • G. De Ninno, D. Gauthier
    University of Nova Gorica, Nova Gorica, Slovenia
  • E. Ferrari, F. Parmigiani
    Università degli Studi di Trieste, Trieste, Italy
  • L. Giannessi
    ENEA C.R. Frascati, Frascati (Roma), Italy
  • B. Mahieu
    CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
  • M. Zangrando
    IOM-CNR, Trieste, Italy
 
  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-6th harmonic. The output of the first stage is then used to seed the second stage. A final wavelengths 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 of microjoules.
*I. Ben-Zvi, K. M. Yang, L. H. Yu, ”The ”fresh-bunch” technique in FELs”, NIM A 318 (1992), p 726-729
 
slides icon Slides MOOBNO01 [25.265 MB]  
 
TUIANO01
Seed Laser Configurations for Advanced Pump-probe Schemes With FELs  
 
  • M.B. Danailov, P. Cinquegrana, A.A. Demidovich, R. Ivanov, G. Kurdi, I. Nikolov, P. Sigalotti
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
 
  This work presents novel techniques developed and under development at the FERMI FEL for implementing new modalities of FEL operation allowing pump-probe experiments with practically no jitter between the pump and probe pulses. One of the proposed techniques takes advantage of the fact that in seeded FELs the exact time at which FEL pulses are generated is locked to the one of the seed laser, and uses a part of the seed laser light for pump-probe experiments. We are presenting the design of a scheme implementing this idea at the FERMI FEL. We address the design of the optical beam transport as well as of the high performance feedbacks driven by optically derived error signals needed to cancel the temporal and pointing drifts. Another new technique, described for the first time to our knowledge, is the use of a double-pulse seed laser which seeds the same electron bunch and allows to generate two FEL pulses with tunable time delay and wavelengths. First experimental results are presented.  
 
TUOBNO02
Optical-EUV Pump and Probe Experiments With Variable Polarization on the Newly Open LDM Beamline of FERMI@Elettra  
 
  • P. Finetti, R. Borghes, C. Callegari, P. Cinquegrana, M.B. Danailov, A.A. Demidovich, C. Fava, S. Gerusina, C. Grazioli, R. Ivanov, G. Kurdi, M. Lonza, N. Mahne, I. Nikolov, L. Pivetta, O. Plekan, L. Raimondi, P. Sigalotti, C. Svetina, D. Zangrando, M. Zangrando
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • L. Avaldi, P. Bolognesi, M. Coreno, P. O’Keeffe
    CNR - IMIP, Trieste, Italy
  • G. De Ninno
    University of Nova Gorica, Nova Gorica, Slovenia
  • M. Di Fraia
    Università degli Studi di Trieste, Trieste, Italy
  • M. Ilchen, T. Mazza, M. Meyer, A.J. Rafipoor
    XFEL. EU, Hamburg, Germany
  • K. Ueda
    Tohoku University, Institute of Multidisciplinary Research for Advanced Materials, Sendai, Japan
 
  Two color experiments are now available to users at the low-density matter beamline (LDM) operating at the Free Electron Laser (FEL) source FERMI@Elettra [1]. The seeded FEL method used at FERMI allows generation of high power, coherent pulses in the femtosecond regime, with a high level of shot-to-shot stability. Variable polarization is also available. LDM is dedicated to atomic, molecular and cluster physics. The LDM end-station, equipped with a velocity map imaging and a time-of-flight detector [2], is an ideal tool to characterize fast multiphoton processes. LDM was open to users in December 2012 and in February 2013 performed its first pump and probe experiment on photoionization of atomic He and generation of spectral sidebands. The FERMI FEL-1 source, delivered EUV photons with several tens of microjoule per pulse (about 100 fs wide) in a tunable wavelength range from 65 to 20 nm, while the 780 nm, optical pulses were from the same Ti:sapphire laser used to form the FEL seed pulse. This paper gives details about the pump and probe experimental setup and shows the straightforward use of the pump and probe data to measure the FEL pulse width.
[1] E. Allaria et al., Nature Photonics, 6, 699 (2012).
[2] V. Lyamayev et al., J. Phys B: At. Mol. Opt. Phys.-B/466820/SPE/12380
 
slides icon Slides TUOBNO02 [3.956 MB]  
 
THIANO01 Double Stage Seeded FEL with Fresh Bunch Injection Technique at FERMI 723
 
  • E. Allaria, D. Castronovo, P. Cinquegrana, G. D'Auria, M. Dal Forno, M.B. Danailov, G. De Ninno, A.A. Demidovich, S. Di Mitri, 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, C. Spezzani, M. Svandrlik, C. Svetina, M. Trovò, M. Veronese, D. Zangrando, M. Zangrando
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • M. Dal Forno
    DEEI, Trieste, Italy
  • G. De Ninno, D. Gauthier
    University of Nova Gorica, Nova Gorica, Slovenia
  • E. Ferrari, F. Parmigiani
    Università degli Studi di Trieste, Trieste, Italy
  • L. Giannessi
    ENEA C.R. Frascati, Frascati (Roma), Italy
  • B. Mahieu
    CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
  • M. Zangrando
    IOM-CNR, Trieste, Italy
 
  Seeding a FEL with an external coherent source has been extensively studied in the last decades as it can provide a way to enhance the radiation brightness and stability, with respect to that available from SASE. An efficient scheme for seed a VUV-soft x ray FEL uses, a powerful, long wavelength external laser to induce on the electron beam coherent bunching at the harmonics of the laser wavelength. When the bunching is further amplified by FEL interaction in the radiator, the scheme is called high gain harmonic generation (HGHG). The need of high power seed sources and of small energy spread are at the main limits for a direct extension of the HGHG scheme to short wavelengths. The fresh bunch scheme was proposed as a way to overcome these limitations; the scheme foresees the FEL radiation produced by one HGHG stage as an external seed in a second HGHG stage. We report the latest results obtained at FERMI that uses the two-stage HGHG scheme for generation of FEL pulses in the soft x-ray. A characterization of the FEL performance in terms of power, bandwidth and stability is reported. Starting from the FERMI results we will discuss extension of the scheme toward shorter wavelengths.  
slides icon Slides THIANO01 [9.355 MB]  
 
THOCNO04 Jitter-free Time Resolved Resonant CDI Experiments Using Two-color FEL Pulses Generated by the Same Electron Bunch 753
 
  • M. Zangrando, E. Allaria, F. Bencivenga, F. Capotondi, D. Castronovo, P. Cinquegrana, M.B. Danailov, G. De Ninno, A.A. Demidovich, S. Di Mitri, B. Diviacco, W.M. Fawley, E. Ferrari, L. Fröhlich, L. Giannessi, R. Ivanov, M. Kiskinova, B. Mahieu, N. Mahne, C. Masciovecchio, I. Nikolov, E. Pedersoli, G. Penco, L. Raimondi, C. Serpico, P. Sigalotti, S. Spampinati, C. Spezzani, C. Svetina, M. Trovò
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • G. De Ninno, D. Gauthier
    University of Nova Gorica, Nova Gorica, Slovenia
  • D. Fausti
    Università degli Studi di Trieste, Trieste, Italy
  • L. Giannessi
    ENEA C.R. Frascati, Frascati (Roma), Italy
  • M. Zangrando
    IOM-CNR, Trieste, Italy
 
  The generation of two-color FEL pulses by the same electron bunch at FERMI-FEL has opened unprecedented opportunity for jitter-free FEL pump-FEL probe time resolved coherent diffraction imaging (CDI) experiments in order to access spatial aspects in dynamic processes. This possibility was first explored in proof-of-principle resonant CDI experiments using specially designed sample consisting of Ti grating. The measurements performed tuning the energies of the FEL pulses to the Ti M-absorption edge clearly demonstrated the time dependence of Ti optical constants while varying the FEL-pump intensity and probe time delay. The next planned CDI experiments in 2013 will explore transient states in multicomponent nanostructures and magnetic systems, using the controlled linear or circular polarization of the two-color FEL pulses with temporal resolution in the fs to ps range.  
slides icon Slides THOCNO04 [8.778 MB]