Author: Ratner, D.F.
Paper Title Page
WEYB02
 Hard X-ray Self-seeding at the Linac Coherent Light Source  
 
  • P. Emma, J.W. Amann, F.-J. Decker, Y.T. Ding, Y. Feng, J.C. Frisch, D. Fritz, J.B. Hastings, Z. Huang, J. Krzywinski, H. Loos, A.A. Lutman, H.-D. Nuhn, D.F. Ratner, J.A. Rzepiela, S. Spampinati, D.R. Walz, J.J. Welch, J. Wu, D. Zhu
    SLAC, Menlo Park, California, USA
  • W. Berg, R.R. Lindberg, D. Shu, Yu. Shvyd'ko, S. Stoupin, E. Trakhtenberg, A. Zholents
    ANL, Argonne, USA
  • V.D. Blank, S. Terentiev
    TISNCM, Troitsk, Russia
  
  Funding: Work supported by US Department of Energy, contract number DE-AC02-76SF00515.
We report on experimental results of FEL self-seeding with Angstrom wavelengths at the Linac Coherent Light Source (LCLS) at SLAC. The scheme, suggested at DESY*, replaces the 16th 4-m long undulator segment (out of 33 total) with a weak magnetic chicane and a diamond-based monochromator in Bragg transmission geometry. The monochromatized SASE FEL pulse from the first half of the undulator line then seeds the second half. This demonstration of hard x-ray self-seeding is shown to narrow the FEL bandwidth by a factor 40-50, allows longitudinally coherent x-ray pulses near the Fourier-transform limit, and may eventually allow an increases in peak brightness by 1-2 orders of magnitude after applying an aggressive undulator field taper.
* G. Geloni, V. Kocharyan, E. Saldin, DESY 10-133, Aug. 2010. 		 
slides icon Slides WEYB02 [5.946 MB]  
 
THAP02
 APS/DPB 2012 Outstanding Doctoral Thesis Research in Beam Physics  
 
  • D.F. Ratner
    Stanford University, Stanford, California, USA
  
  Control of collective properties of relativistic particles is increasingly important in modern accelerators. In particular, shot noise affects accelerator performance by driving instabilities or by competing with coherent processes. A beam with reduced shot noise current fluctuations could have diverse accelerator applications, including lowering power requirements for seeded Free Electron Lasers (FELs). In this talk I will describe recent theoretical models and experimental observations of shot noise reduction in relativistic electrons.  
slides icon Slides THAP02 [3.746 MB]