Author: Deng, H.X.
Paper Title Page
Harmonic Lasing & Gain Cascading: More Efficient X-Ray Free Electron Laser Oscillators  
  • H.X. Deng
    SINAP, Shanghai, People's Republic of China
  In this talk, I will focus on the recent theoretical progresses on X-ray free-electron laser oscillator (XFELO). A simplified one-dimensional theoretical model for fast XFELO optimization, harmonic lasing XFELO scheme which reduces the requiered beam energy for a interested radiation wavelength, and the gain-cascading scheme which may increase the pulse energy and the peak power of XFELO will be presented.  
slides icon Slides MOBB01 [3.468 MB]  
Design Study and Preparations for the Echo-30 Experiment at SXFEL  
  • C. Feng, S. Chen, H.X. Deng, B. Liu, D. Wang, X.T. Wang, Z.T. Zhao
    SINAP, Shanghai, People's Republic of China
  • D. Xiang
    Shanghai Jiao Tong University, Shanghai, People's Republic of China
  In this work, design study and hardware preparations for the echo-30 experiment at the SXFEL test facility are presented. With the realistic parameters of the SXFEL, start-to-end simulations considering various three-dimensional effects have been carried out, and the simulation results demonstrate that a single-stage EEHG can generate high-power soft x-ray radiation pulses with narrow bandwidth directly from UV seed lasers. We also show the preparations of the seed lasers, undulators and photon beam diagnostics for the echo-30 experiment at the SXFEL.  
Considerations on X-ray FEL Oscillator Operation for the Shanghai Coherent Light Facility  
  • K. Li, H.X. Deng
    SINAP, Shanghai, People's Republic of China
  Shanghai Coherent Light Facility (SCLF) is a quasi-CW hard X-ray free electron laser user facility which is recently proposed. Due to the high repetition rate and high quality electron beams, it is straightforward to consider an X-ray free electron laser oscillator (XFELO) operation for SCLF. The main parameters required for the undulator, X-ray cavity and electron beam for XFELO operation are discussed, and the performances of the expected fully coherent X-ray pulses are investigated and optimized by the combination of theoretical analysis and numerical simulation.  
Design of the Beam Distribution System for a Soft X-Ray FEL User Facility in Shanghai  
  • S. Chen, H.X. Deng, C. Feng, B. Liu, D. Wang
    SINAP, Shanghai, People's Republic of China
  A soft X-ray user facility will be upgraded from an existing soft X-ray test facility in Shanghai. One or more extended FEL undulator lines will be constructed parallel to the previous undulator line. For simultaneous operation of several undulator lines, a beam distribution system is required for spreading the electron bunches from linac to each undulator lines. In this work, the physics design of such a beam distribution system will be described.  
WEP063 A Two-in-One Type Undulator 1
  • D. Wang, H.X. Deng, Z. Jiang
    SINAP, Shanghai, People's Republic of China
  Funding: This work is supported by the Ministry of Science and Technology of China.
The typical X-ray free electron lasers have long tunnels to accommodate high energy electron linear accelerator and long undulator line to produce intense coherent radiations at very short wavelengths. The number of undulator lines is limited by the available space in the tunnel. This is especially true for those facilities that adopt underground tunnels or utilize the existing tunnels originally built for other purpose. This work explored the possibility to better use the tunnel space for accommodating more FEL undulator lines by designing a new type of undulator structure.