Keyword Index: A   B   C   D   E   F   G   H   I   K   L   M   O   P   Q   R   S   T   U   V   W   X

bunch-compressor

Paper Title Other Keywords Page
MOPP035 Bunch Length Measurements Using a Martin-Puplett Interferometer at the VUV-FEL radiation, interferometer, electron, csr 114
 
  • L. Fröhlich, O. Grimm
    DESY, Hamburg
  
 

The longitudinal charge distribution of short electron bunches can be characterized by a measurement of their coherent far-infrared radiation spectrum. This paper will present the results obtained at the DESY VUV-FEL linear accelerator by observation of synchrotron radiation with a Martin-Puplett interferometer. The reconstructed bunch shapes are strongly asymmetric with a full width at half maximum of about 1 ps.

   
    
MOPP039 Present Performance and Future Requirements of the RF Plants for the FERMI Project linac, fel, klystron, pulse-length 126
 
  • G. D'Auria, P. Craievich, M. Ferianis, M.M. Milloch
    ELETTRA, Basovizza, Trieste
  • dc. Cheever, T. Zwart
    MIT, Middleton, Massachusetts
  • L.R. Doolittle, A. Ratti
    LBNL, Berkeley, California
  
 

The VUV soft x-ray FEL user facility, FERMI@Elettra, will use the existing 1.2 GeV linac to produce, in two separate phases, 100-40 nm and 40-10 nm, intense photon beams with single stage and double stage harmonic generation schemes respectively. To fulfill the stringent requirements of the project the present RF systems will be completely revised and upgraded. The work presented here describes the present performances of the system and plans for the linac upgrades to meet the required system specifications for FEL operation.

   
    
TUOB004 Bunch Compression Stability Dependence on RF Parameters linac, emittance, acceleration, simulation 250
 
  • T. Limberg, M. Dohlus
    DESY, Hamburg
  
 

In present designs for FEL's with high electron peak currents and short bunch lengths, higher harmonic RF systems are often used to optimize the final longitudinal charge distributions. This opens degrees of freedom for the choice of RF phases and amplitudes to achieve the necessary peak current with a reasonable longitudinal bunch shape. It had been found empirically that different working points result in different tolerances for phases and amplitudes. We give an analytical expression for the sensitivity of the compression factor on phase and amplitude jitter for a bunch compression scheme involving two RF systems and two magnetic chicanes as well numerical results for the case of the European XFEL.

   
    
THPP035 Observation of Femtosecond Bunch Length Using a Transverse Deflecting Structure linac, acceleration, sase, energy-spread 538
 
  • M. Huening, A. Bolzmann, H. Schlarb
    DESY, Hamburg
  • J.C. Frisch, D.J. McCormick, M.C. Ross, T.J. Smith
    SLAC, Menlo Park, California
  • J. Rossbach
    Uni HH, Hamburg
  
 

The design of the VUV-FEL at DESY demands bunch lengths in the order of 50 fs and below.For the diagnostic of such very short bunches a transverse deflecting RF structure (LOLA) has been installed which streaks the beam according to the longitudinal distribution. Tests in the VUV-FEL yielded a rich substructure of the bunches. The most pronounced peak in the has a rms length of approximately 50 fs during FEL operation and below 20 fs FWHM at maximum compression. Depending on the transverse focusing a resolution between 10-50 fs was achieved.