Author: Emma, P.
Paper Title Page
MOD01
Status of the LCLS-II FEL Project at SLAC  
 
  • P. Emma
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-76SF00515.
LCLS-II is a major new Free-Electron Laser (FEL) facility being built at SLAC, with collaborators from other US laboratories at ANL, Cornell, FNAL, LBNL, and TJNAF. This project aims to upgrade the operating LCLS-I facility by building a new 4-GeV superconducting RF (SRF) linac to provide continuous wave (CW) operation of two new FELs at beam rates of up to 1 MHz. The existing fixed-gap FEL undulator will be replaced by two new parallel adjustable-gap undulators providing an FEL spectral tuning range from 0.2 keV to 25 keV with average x-ray power levels approaching 1 kW. The existing 15-GeV copper linac in the last 3rd of the SLAC linac will be maintained as a low-rate, high-energy FEL driver in complementary operations with the new SRF linac. We present a brief status of the project, some of the latest test results, and thoughts on further facility expansion in the long term.
 
 
TUC03
High-Flux, Fully Coherent X-Ray FEL Oscillator  
 
  • K.-J. Kim, S.P. Kearney, T. Kolodziej, R.R. Lindberg, X. Shi, D. Shu, Yu. Shvyd'ko
    ANL, Argonne, Illinois, USA
  • K.L.F. Bane, Y. Ding, P. Emma, W.M. Fawley, J.B. Hastings, Z. Huang, J. Krzywinski, G. Marcus, T.J. Maxwell
    SLAC, Menlo Park, California, USA
  • V.D. Blank, S. Terentiev
    TISNCM, Troitsk, Russia
  • W.M. Fawley
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • C. Grizolli
    LNLS, Campinas, Brazil
  • W. Qin
    PKU, Beijing, People's Republic of China
  • S. Stoupin
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • J. Zemella
    DESY, Hamburg, Germany
 
  Funding: The ANL part of this work is supported by the U.S. DOE Office of Science under Contract No. DE-AC02-06CH11357 and the SLAC part under contract No. DE-AC02-76SF00515.
By optimizing the parameters of the accelerator, undulator, and the optical cavity, an XFELO driven by an 8-GeV superconducting linac is predicted to produce 10zEhNZeHn photons per pulse at the important photon energies around 14.4 keV.* This is an order of magnitude larger than that in previous designs.** With a BW of 3 meV (FWHM), rep rate of 1 MHz, and taking into account the full coherence, the spectral brightness is then 2×1026 photons per (mm2mr2 0.1\% BW), which is higher than any other source currently operating or anticipated in the future. Experiments at APS beam lines have shown that a high-quality diamond crystal can survive the power density (~15 kW/mm2) expected at the XFELO intra-cavity crystals preserving the high reflectivity.*** The compound refractive lenses can serve as the focusing element. Adding an XFELO to the suite of other FEL sources will, at a minor incremental cost but with a major scientific payoff, significantly expand the scientific capabilities at superconducting linac-based XFEL facilities, such as the European XFEL, the proposed LCLS-II High Energy upgrade and the XFEL project in Shanghai.
* W. Qin et al., this conference.
** R.R. Lindberg et al., Phys. Rev. ST Accel. Beams, vol 14, 403 (2011).
*** T. Kolodziej et al., this conference.
 
 
TUP025
Beam Shaping to Improve the Free-Electron Laser Performance at the Linac Coherent Light Source  
 
  • Y. Ding, K.L.F. Bane, W.S. Colocho, F.-J. Decker, P. Emma, J.C. Frisch, M.W. Guetg, Z. Huang, R.H. Iverson, J. Krzywinski, H. Loos, A.A. Lutman, T.J. Maxwell, H.-D. Nuhn, D.F. Ratner, J.L. Turner, J.J. Welch, F. Zhou
    SLAC, Menlo Park, California, USA
 
  A new operating mode has been developed for the Linac Coherent Light Source (LCLS) in which we shape the longitudinal phase space of the electron beam. This mode of operation is realized using a horizontal collimator located in the middle of the first bunch compressor to truncate the head and tail of the beam. With this method, the electron beam longitudinal phase space and current profile are re-shaped, and improvement in lasing performance can be realized. We present experimental studies at the LCLS of the beam shaping effects on the free electron laser performance.  
 
WEP043 Tune-Up Simulations for LCLS-II 1
 
  • M.W. Guetg, P. Emma
    SLAC, Menlo Park, California, USA
 
  The planned superconducting LCLS-II linac poses new operational constraints with respect to the existing copper linac currently operated for LCLS. We present the results of exhaustive accelerator simulations, including realistic machine errors and exploring beam tune-up strategies. The results are used to pin-point the required beam diagnostics and the key correction elements. Specifically, these simulations concentrate on longitudinal and transverse beam matching as well as orbit and dispersion control through the new linac and up to the hard x-ray FEL. Dispersion control is achieved by a novel method presented within this paper.  
 
WET01
Beam-based alignment of undulators for free-electron lasers  
 
  • P. Emma
    SLAC, Menlo Park, California, USA
 
  Wed tutorial