Author: Briquez, F.
Paper Title Page
TUPA06 Seeding Schemes on the French FEL Project LUNEX5 198
 
  • C. Evain, F. Briquez, M.-E. Couprie, M. Labat, A. Loulergue
    SOLEIL, Gif-sur-Yvette, France
  • V. Malka
    LOA, Palaiseau, France
 
  LUNEX5 is a single pass FEL project producing coherent synchrotron radiation with, in a first step, an electron bunch accelerated in conventional RF cavities up to 300 MeV. It is planned to work in a seeded configuration where the longitudinal coherence of the emitted light is improved and the gain length reduced, compared to the SASE configuration (Self-Amplified Spontaneous Emission). Two seeding schemes are considered: High order Harmonic in Gas seeding and EEHG scheme (Echo Enabled Harmonic Generation). Preliminary simulation results indicate that these two schemes permit to reach the saturation below a wavelength of 7 nm, and with less undulator periods for the EEHG scheme. Finally, the feasibility of plasma acceleration based FEL will also be investigated on this facility.  
 
TUPA09 LUNEX5: A FEL Project Towards the Fifth Generation in France 208
 
  • M.-E. Couprie, C. Benabderrahmane, F. Briquez, J. Daillant, J.-C. Denard, C. Evain, P. Eymard, F. Ferrari, J.-M. Filhol, M. Labat, A. Loulergue, P. Marchand, C. Miron, P. Morin, F. Polack
    SOLEIL, Gif-sur-Yvette, France
  • S. Bielawski, C. Szwaj
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
  • B. Carré
    CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
  • N. Delerue, R. Roux, A. Variola
    LAL, Orsay, France
  • G. Lambert, V. Malka, A. Rousse
    LOA, Palaiseau, France
  • J. Lüning
    CCPMR, Paris, France
 
  LUNEX5 (free electron Laser Using a New accelerator for the Exploitation of X-ray radiation of 5th generation) aims at investigating the production of short intense and coherent pulses in the soft X rays region (down to 7 nm on the fifth harmonic). It comprises a free electron laser in the seeded configuration (High order Harmonic in Gas seeding and Echo Enable Harmonic Generation) using a conventional linear accelerator of 300 MeV. The FEL beamline including 15 m of in vacuum (potentially cryogenic undulators) of 15 and 30 mm period is designed so as to also accommodate a Laser Wake Field Accelerator (LWFA) ranging from 0.3 to 1 GeV, relying on electron beam parameters produced and accelerated by either the 60 TW laser of LOA or by the 10 PW APOLLON laser of ILE. After the completion and testing of the FEL with the conventional accelerator installed inside the SOLEIL booster inner area, the FEL line can be transported to a LWFA. A laser could alternatively be implemented at SOLEIL for starting testing the principles of a fifth generation light source.  
 
WEOB3
Seeding Experiments at SPARC  
 
  • M. Labat, F. Briquez, M.-E. Couprie
    SOLEIL, Gif-sur-Yvette, France
  • D. Alesini, M. Bellaveglia, M. Castellano, E. Chiadroni, G. Di Pirro, A. Drago, M. Ferrario, L. Ficcadenti, A. Gallo, G. Gatti, A. Ghigo, E. Pace, B. Spataro, C. Vaccarezza
    INFN/LNF, Frascati (Roma), Italy
  • A. Bacci, V. Petrillo, A.R. Rossi, L. Serafini
    Istituto Nazionale di Fisica Nucleare, Milano, Italy
  • M. Bougeard, B. Carré, D. Garzella
    CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
  • A. Cianchi
    Università di Roma II Tor Vergata, Roma, Italy
  • F. Ciocci, G. Dattoli, M. Del Franco, L. Giannessi, A. Petralia, M. Quattromini, C. Ronsivalle, E. Sabia, I.P. Spassovsky, V. Surrenti
    ENEA C.R. Frascati, Frascati (Roma), Italy
  • L. Cultrera
    CLASSE, Ithaca, New York, USA
  • D. Filippetto
    LBNL, Berkeley, California, USA
  • F. Frassetto, L. P. Poletto
    LUXOR, Padova, Italy
  • G. Lambert
    LOA, Palaiseau, France
  • G. Marcus, J.B. Rosenzweig
    UCLA, Los Angeles, California, USA
  • M. Migliorati, A. Mostacci, L. Palumbo
    Rome University La Sapienza, Roma, Italy
  • J.V. Rau
    ISM-CNR, Rome, Italy
  • M. Serluca
    INFN-Roma, Roma, Italy
  • C. Vicario
    PSI, Villigen PSI, Switzerland
 
  The SPARC FEL amplifier has been configured as a single stage HGHG FEL with a modulator and a radiator operating at the second harmonic. The HGHG cascade has been seeded with harmonics generated in a gas cell where a Ti:Sa laser pulse of 120 fs of duration is converted into higher harmonics. The cascaded FEL configuration obtained by tuning the undulator gaps has been studied by varying the number of modulators and radiators to optimize the conversion efficiency. The process of harmonic generation in a free electron laser operating in superradiant regime has been also analysed. Harmonic generation is expected to be efficient because of the quasi steady-state distribution of the e-beam phase space predicted in this regime. Harmonics up to the 11th have been experimentally observed.  
slides icon Slides WEOB3 [5.198 MB]  
 
WEPA14 Effect of a Quasiperiodic Undulator on FEL Radiation 352
 
  • F. Briquez, C. Benabderrahmane, M.-E. Couprie, C. Evain, M. Labat
    SOLEIL, Gif-sur-Yvette, France
 
  The operation of conventional undulators results from an interference scheme in order to generate radiation of a fundamental wavelength and its harmonics. Whereas these harmonics are in most of the cases useful to reach higher energies, it is profitable in specific configurations to shift or reduce them, for instance to limit power on optics or to distinguish between one or two photon process in user experiments. This can be performed by so-called quasi-periodic undulators in which the periodicity of the magnetic field is destructed. In this case, the field amplitude is reduced on a few positions among the axis, inducing a destruction of the interference scheme. Such undulators are commonly used to generate spontaneous emission in synchrotron radiation facilities but could also be installed in Free Electron Lasers. The emitted radiation of the quasi-periodic undulator is compared with the usual configuration one, in the case of LUNEX5. Simulations using GENESIS code are described and results are discussed.