Author: Chao, Y.-C.
Paper Title Page
Dispersion Based Fresh Slice Scheme  
  • M.W. Guetg, Y.-C. Chao, F.-J. Decker, Y. Ding, A.S. Fisher, Z. Huang, A.A. Lutman, T.J. Maxwell
    SLAC, Menlo Park, California, USA
  This paper presents experimental studies of the dispersion based fresh slice scheme at LCLS. This scheme lead to pulse shortening resulting in pulse lengths below 10 fs. Careful orbit control allowed generating two colors with individual delay control and color separation of more than 3%. Unlike the dechirper based fresh slice scheme, the dispersion based fresh slice scheme does not require additional hardware. Another key benefit of this scheme is a strong spectral stability making the photon pulse energy independent of the electron energy jitter.  
Generation of Two-Color X-Ray Free-Electron Lasers Using a Matching-Based Fresh-Slice Method  
  • W. Qin, Y.-C. Chao, Y. Ding, A.A. Lutman
    SLAC, Menlo Park, California, USA
  Two-color high intensity X-ray free-electron lasers (FELs) provide powerful tools for probing ultrafast dynamic systems. A novel concept of realizing fresh-slice two-color lasing through slice-dependent transverse mismatch has been proposed by one of the authors.* In this paper we present a feasible example following this concept based on the Linac Coherent Light Source parameters. Time-dependent mismatch along the bunch is generated by a passive dechirper module and controlled by downstream matching sections, enabling FEL lasing at different wavelengths with a split undulator configuration. Simulations for soft X-ray FELs show that tens of gigawatts pulses with femtosecond duration can be generated.
* Y. Chao, SLAC Report No. SLAC-PUB-16935, 2016.