Author: Murokh, A.Y.
Paper Title Page
FRB03
 Tapering Enhanced Stimulated Superradiant Amplification  
 
  • J.P. Duris, P. Musumeci
    UCLA, Los Angeles, California, USA
  • A.Y. Murokh
    RadiaBeam, Marina del Rey, California, USA
  
  The electrical to optical conversion efficiency of FELs is typically limited to less than 1 percent. Efforts to improve conversion efficiency have generally involved undulator tapering to drive the interaction beyond saturation in combination with focusing the electron beam to compensate gain guiding losses within undulator. Here we propose a scheme whereby a coherent radiation seed is focused into a strongly tapered undulator to violently decelerate electrons, thereby converting as much as 70 percent of e-beam energy to coherent radiation. By tapering the undulator to accommodate the radiation growth, a modest input seed may be used to drive the FEL interaction far beyond saturation in order to achieve high electrical to optical conversion efficiency. The scheme relies on a prebunched beam and a seed laser focused into a strongly tapered undulator and is therefore called tapering enhanced stimulated superradiant amplification (TESSA).  
slides icon Slides FRB03 [1.100 MB]  
 
THP033 Mechanical Design for a Corrugated Plate Dechirper System for LCLS 785
 
  • M.A. Harrison, P. Frigola, D.W. Martin, A.Y. Murokh, M. Ruelas
    RadiaBeam Systems, Santa Monica, California, USA
  • Z. Huang, R.H. Iverson, T.J. Maxwell, Z. Zhang
    SLAC, Menlo Park, California, USA
  
  Funding: This work is supported by Department of Energy grant number DE-SC0009550.
RadiaBeam Systems is developing a novel passive chirp removal system using corrugated plates as studied by Bane and Stupakov.* Following on from low-energy experiments at BNL-ATF,** RBS will install a much larger and powerful system for removing the chirp from the 3-GeV beams in the LTU section at LCLS. The larger plates will present new challenges in the areas of manufacturing and mechanical control. In this paper we review the requirements for the dimensions of the corrugated plates for proper operation and the infrastructure necessary for precisely placing the plates so as not to adversely disrupt the beam.
* K. Bane, et al "Corrugated Pipe as a Beam Dechirper," SLAC-PUB-14925, 2012
** Harrison, M., et al "Removal of Residual Chirp in Compressed Beams Using a Passive Wakefield Technique." NaPAC13, 2013 		 
 
THP034 Further Analysis of Corrugated Plate Dechirper Experiment at BNL-ATF 788
 
  • M.A. Harrison, G. Andonian, P. Frigola, A.Y. Murokh, M. Ruelas, A.V. Smirnov
    RadiaBeam Systems, Santa Monica, California, USA
  • M.G. Fedurin
    BNL, Upton, Long Island, New York, USA
  
  Funding: This work is supported by Department of Energy grant number DE-SC0009550.
RadiaBeam Systems successfully completed testing of a proof-of-concept corrugated plate dechirper at the Brookhaven National Laboratory Accelerator Test Facility.* Such passive devices should prove indispensable for the efficient operation of future XFEL facilities. These experiments demonstrated a narrowing of the energy spectrum in chirped beam bunches at 57.6 MeV. In this paper, we compare these results with results from Elegant simulations of the BNL-ATF beam. We also compare GdfidL simulations of the wakefield with the analytic results of Bane and Stupakov.**
* Harrison, M., et al "Removal of Residual Chirp in Compressed Beams Using a Passive Wakefield Technique." NaPAC13, 2013
** K. Bane, et al "Corrugated Pipe as a Beam Dechirper," SLAC-PUB-14925, 2012