Author: Tanikawa, T.
Paper Title Page
WEOB03
 Laser-induced CSR : Seeding of the Microbunching Instability in Storage Rings  
 
  • E. Roussel, S. Bielawski, C. Evain, C. Szwaj, T. Tanikawa
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
  • M. Adachi, M. Katoh
    UVSOR, Okazaki, Japan
  • M. Hosaka, N. Yamamoto
    Nagoya University, Nagoya, Japan
  • M. Le Parquier
    CERLA, Villeneuve d'Ascq, France
  • H. Zen
    Kyoto University, Institute for Advanced Energy, Kyoto, Japan
  
  Microbunching instability arises both in Linear Free Electron Laser and in storage rings due to the interaction of the electrons with their own radiation, mainly in dipoles (bending magnets in storage rings and chicanes in linear FEL). This instability leads to the formation of micro-structures in the longitudinal phase-space (typically in the mm range in the longitudinal profile) and limits the performances of these accelerator based ligth sources. We show that the interaction of the electron bunch with an external laser pulse, whose envelope is modulated at a Terahertz frequency (associated to mm wavelength), allows to investigate the dynamics of electron bunches in storage rings during the micro-bunching instability. Here, we achieve experiments at UVSOR-II* around the CSR instability threshold. We also perform numerical calculations using a one-dimensional Fokker-Planck-Vlasov modeling taking into account CSR wakefield. This seeding mechanism highlights that CSR depends on the wakefields for some ranges of excited wavenumber.
* C. Evain et al., Phys. Rev. ST Accel. Beams 13, 090703 (2010); S. Bielawski et al., Nature Physics 4, 390 (2008). 		 
slides icon Slides WEOB03 [2.523 MB]  
 
TUPD05 Sensitivities of FEL Parameters in LUNEX5 in France by GENESIS Simulation 233
 
  • T. Tanikawa, M.-E. Couprie, M. Labat, A. Loulergue
    SOLEIL, Gif-sur-Yvette, France
  • S. Bielawski, C. Evain, C. Szwaj
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
  
  LUNEX5 (free-electron Laser (FEL) Using a New accelerator for the Exploitation of X-ray radiation of 5th generation) aims at producing short and intense laser pulse in the soft x-ray region (target wavelength is 13 and 20 nm). This FEL comports either a conventional linear accelerator or a laser wakefield accelerator, and includes innovative schemes such an echo-enable harmonic generation and higher-order harmonics seeding generated in gases to obtain the high spatio-temporal coherent radiation. Sensitivities of FEL radiation property to parameter such as beam energy, energy spread, bunch length, input seed power have been studied by using GENESIS.  
 
TUPD17 Seeding of SPARC-FEL with a Tunable Fibre-based Source 269
 
  • N.Y. Joly
    University of Erlangen-Nuremberg, Erlangen-Nuremberg, Germany
  • S. Bielawski
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
  • W. Chang, P. Hölzer, K. Mak, P.St.J. Russell, F. Tani, J.C. Travers
    Max Planck Institute for the Science of Light, Erlangen, Germany
  • F. Ciocci, L. Giannessi, A. Petralia, M. Quattromini
    ENEA C.R. Frascati, Frascati (Roma), Italy
  • M.-E. Couprie, M. Labat, T. Tanikawa
    SOLEIL, Gif-sur-Yvette, France
  • G. De Ninno, B. Mahieu
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • G. Gatti
    INFN/LNF, Frascati (Roma), Italy
  • V. Petrillo
    Istituto Nazionale di Fisica Nucleare, Milano, Italy
  • J.V. Rau
    ISM-CNR, Rome, Italy
  
  Instead of seeding a free electron laser in the UV-VUV with a frequency doubled or tripled laser or high order harmonics, here we investigate and present the first results on seeding SPARC-FEL with a fiber-based tunable ultraviolet source. The seed generation system consists of a kagomé hollow-core photonic crystal fiber filled with noble gas. Diffraction-limited DUV pulses of >50 nJ and fs-duration which are continuously tunable from below 200 nm to above 300 nm are generated. The process is based on soliton-effect self-compression of the pump pulse down to a few optical cycles, accompanied by the emission of a resonant dispersive wave in the DUV spectral region. The quality of the compression highly depends on the pump pulse duration, and ideally, pulses <60 fs should be used. Our experimental set-up and associated GENESIS simulations enable us to study the utility of the seed tunability, and the influence of the seed quality, on the performance of the SPARC-FEL in the 200-300 nm range.  
 
FROA03 The LUNEX5 Project 678
 
  • M.-E. Couprie
    CEA/DSM, Gif-sur-Yvette, France
  • C. Benabderrahmane, P. Betinelli-Deck, F. Bouvet, A. Buteau, L. Cassinari, J. Daillant, J.-C. Denard, C. Evain, P. Eymard, B. Gagey, C. Herbeaux, M. Labat, A. Lestrade, A. Loulergue, P. Marchand, O. Marcouillé, J.L. Marlats, C. Miron, P. Morin, A. Nadji, F. Polack, J.B. Pruvost, F. Ribeiro, J.P. Ricaud, P. Roy, T. Tanikawa
    SOLEIL, Gif-sur-Yvette, France
  • S. Bielawski, C. Szwaj
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
  • B. Carré
    CEA, Gif-sur-Yvette, France
  • J. Chavanne, L. Farvacque, G. Lebec
    ESRF, Grenoble, France
  • X. Davoine
    CEA/DAM/DIF, Arpajon, France
  • G. Devanz, M. Luong
    CEA/DSM/IRFU, France
  • A. Dubois, J. Lüning
    CCPMR, Paris, France
  • G. Lambert, R. Lehe, A. Lifschitz, V. Malka, A. Rousse, K. Ta Phuoc, C. Thaury
    LOA, Palaiseau, France
  • R. Roux
    LAL, Orsay, 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-ray region (with two particular targeted wavelengths of 20 and 13 nm on the fundamental wavelength). The project consists of a Free Electron Laser (FEL) line enabling the most advanced seeding configurations (High order Harmonic in Gas seeding and Echo Enable Harmonic Generation) and in-vacuum (potentially cryogenic) undulators of 15 and 30 mm period. Two accelerator types feed this FEL line : a Conventional Linear Accelerator (CLA) with superconducting cavities of 400 MeV for the investigations of the advanced FEL schemes, compatible with a future up-grade for high repetition rate; and a 0.4 - 1 GeV Laser Wake Field Accelerator (LWFA), to be qualified in view of FEL application, in the single spike or seeded regime. Two pilot user experiments for time-resolved studies of isolated species and solid state matter dynamics will take benefit of LUNEX5 FEL radiation and provide feedback of the performance of the different schemes under real user conditions.  
slides icon Slides FROA03 [25.321 MB]