Author: Fu, Q.
Paper Title Page
TUPEA044 The Design of Control System for the Optical Cavity Adjuster of a FEL-THz Source 1232
  • X. Liu, Q. Fu, B. Qin, P. Tan, C. Wang, Y.Q. Xiong, J. Yang, H. Zeng
    HUST, Wuhan, People's Republic of China
  The optical cavity adjuster is an important sub-system in a FEL-THz source, which is used to adjust the position and angle of the optical cavity with a high precision. In view of the requirements of the optical cavity adjuster of the FEL-THz source, this paper presents the design of the control system of the optical cavity adjuster. The design of the control system based on a PC and a motion controller is adopted. The motion controller controls high-precision linear stage to adjust linear direction and picomotors are controlled to enable the adjustment of roll and yaw. According to relevant calculation, the range of linear direction and the accuracy can be reached at ±3mm and 0.2~0.5μm; the range of the adjustment of roll and yaw and the accuracy can be reached at ±2° and 20″. In summing up it can be stated that the design meets the requirements and it also lays the foundation for engineering on developing the optical cavity adjuster.  
TUPWO034 Focusing Magnetic Field Design for a FEL Linac 1949
  • Q.S. Chen, Q. Fu, T. Hu, B. Qin, B. Wu, H. Zeng
    HUST, Wuhan, People's Republic of China
  • J. Li, Y.J. Pei
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  A linac-based Free Electron Laser is planned to be built in Huazhong University of Science and Technology (HUST). As an important part of the whole project, the focusing magnetic field is carefully designed. Space-charge force is calculated at first to give a rough evaluation about the focusing field. Start-to-end simulation shows that the magnetic field has only great effect on spot size and phase space. With the final designed field, 10-ps-length pulse containing 200pC electrons can be got and the corresponding RMS emittance and RMS radius are 7 πmm•mrad and 0.25 mm, respectively. Finally, a new idea (double-peak scheme) is discussed and excitation current is proposed as the evaluation index.  
TUPWO035 Physical Design of Beam Transport Line of a Compact Terahertz FEL 1952
  • H. Zeng, Q.S. Chen, Q. Fu, B. Qin, B. Wu, Y.Q. Xiong
    HUST, Wuhan, People's Republic of China
  • G. Feng, Y.J. Pei
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  The single pass, linac-based compact terahertz source at HUST is now in the physical design stage. To match Twiss parameters and dispersion function of the electron beam at the undulator entrance and get smaller beta function in the whole line, several lattices based on the double bending achromat(DBA) structure were discussed and the optimized design is given with beam dynamics results–calculated by MAD and Trace 3D.  
WEPWA037 Effect of Ground Vibration on the Out-coupled Power in a Terahertz FEL Oscillator 2211
  • Q. Fu, L.Z. Deng, B. Qin, P. Tan, Y.Q. Xiong, Y.B. Yibin, H. Zeng
    HUST, Wuhan, People's Republic of China
  To acquire high power out-coupled, we must ensure the co-axis of electron orbit, optical beam and magnetic field. The propagation of ground vibration through the optical platform will lead to misalignment of the optical axis in the FEL optical cavity. Based on measurement results of the ground vibration, simulations of misalignment are studied with GENESIS+OPC. The tolerance of mirror tilt and offset is also discussed.