Author: Fawley, W.M.
Paper Title Page
WEOBI1
 FEL Commissioning at FERMI@Elettra  
 
  • E. Allaria, P. Craievich, S. Di Mitri, W.M. Fawley, L. Fröhlich, G. Penco, C. Spezzani, M. Trovò
    ELETTRA, Basovizza, Italy
  • G. De Ninno, S. Spampinati
    University of Nova Gorica, Nova Gorica, Slovenia
  • L. Giannessi
    ENEA C.R. Frascati, Frascati (Roma), Italy
  
  The FERMI@Elettra Free Electron Laser (FEL) produced the first coherent photons in December 2010 at the end of the first commissioning phase. Starting from February 2011 the commissioning has continued, leading to an improvement of the FEL performance. In agreement with to the design, FEL-1, the first of the two FERMI free electron lasers, has been producing coherent FEL pulses in the 60 to 20 nm wavelength range. Benefits of the seeded scheme adopted for FERMI have been immediately evident also in the case of a non-optimized electron beam.  
slides icon Slides WEOBI1 [4.528 MB]  
 
TUOA4 Toward TW-level, Hard X-ray Pulses at LCLS 160
 
  • W.M. Fawley, J.C. Frisch, Z. Huang, Y. Jiao, H.-D. Nuhn, C. Pellegrini, J. Wu
    SLAC, Menlo Park, California, USA
  • S. Reiche
    Paul Scherrer Institut, Villigen, Switzerland
  
  Funding: Work supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC02-76SF00515.
Coherent diffraction imaging of complex molecules, like proteins, requires a large number of hard X-ray photons, ~10+13/pulse, within a time ~10 fs or less. This is equivalent to a peak power of about one TW, much larger than that currently generated by LCLS or other proposed X-ray FELs. We study the feasibility of producing such pulses from LCLS and the proposed LCLS-II, employing a configuration beginning with a SASE amplifier, followed by a "self-seeding" crystal monochromator [1], and finishing with a long tapered undulator. Results suggest that TW-level output power at 8 keV is possible, with a total undulator length below 200 m. We use a 40 pC electron bunch charge, normalized transverse emittance of 0.2-mm-mrad, peak current of 4 kA, and electron energy about 14 GeV. We present a tapering strategy that extends the original "resonant particle" formalism by optimizing the transport lattice to maximize optical guiding and enhance net energy extraction. We also discuss the transverse and longitudinal coherence properties of the output radiation pulse. Fluctuation of such a tapered FEL is studied with realistic jitter measured at LCLS and with start-to-end simulation. 		 
slides icon Slides TUOA4 [9.357 MB]