Author: Thongbai, C.
Paper Title Page
MOP025 Electron Beam Properties from a Compact Seeded Terahertz FEL Amplifier at Kyoto University 85
  • K. Damminsek, S. Rimjaem, S. Suphakul, C. Thongbai
    Chiang Mai University, Chiang Mai, Thailand
  • H. Ohgaki, H. Zen
    Kyoto University, Kyoto, Japan
  A compact seeded Terahertz FEL amplifier is started construction at Institute of Advanced Energy, Kyoto University, Japan. The system consists of a 1.6 cell BNL type S-Band photocathode RF-gun, a magnetic bunch compressor in form of a chicane, triplet quadrupole magnets and a short planar undulator. Electron beams from the photocathode RF-gun were measured and compared with the PARMELA simulation results. Numerical and experimental studies on the contribution of the space charge effect were carried out. By using the RF power of 9 MW, the RF phase of 40 degree, the laser pulse energy of 20 μJ, and the solenoid magnet current of 135 A, the electron beam with a bunch charge of 50 pC, a beam energy of around 5 MeV and an RMS emittance of 6-8 mm-mrad was achieved.  
poster icon Poster MOP025 [1.837 MB]  
Export • reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)  
WEP061 Numerical and Experimental Studies on Electron Beam Properties from Asymmetric RF-gun 698
  • S. Rimjaem, N. Chaisueb, J. Saisut, C. Thongbai, W. Thongpakdi
    Chiang Mai University, Chiang Mai, Thailand
  • N. Kangrang
    FNRF, Chiang Mai, Thailand
  • E. Kongmon, K. Kosaentor, P. Wichaisirimongkol
    IST, Chiang Mai, Thailand
  Funding: This work has been supported by the CMU Junior Research Fellowship Program, and the Department of Physics and Materials Science, Faculty of Science, Chiang Mai University.
The electron linear accelerator at the Plasma and Beam Physics Research Facility (PBP-CMU Linac), Chiang Mai University, Thailand, is used to produce femtosecond electron bunches for generation of THz radiation. The main components of the PBP-CMU Linac are a thermionic RF electron gun, an alpha magnet, a travelling wave linac structure, quadrupole lens, steering magnets, and various diagnostic components. The RF-gun consists of a 1.6 S-band standing wave structure and a side-coupling cavity. The 2856 MHz RF wave is transmitted from the klystron to the gun through a rectangular waveguide input-port. Both the RF input-port and the side-coupling cavity cause an asymmetric electromagnetic field distribution inside the gun. The electron beam from the RF-gun has asymmetric transverse shape with an emittance value, which is higher than the beam from the symmetric fields. The problems are increased when the beam is transported from the gun through the whole accelerator system. Beam dynamic simulations are performed to investigate the effect of the asymmetric fields on the electron properties by using the codes PARMELA and ELEGANT. An integrated electron beam diagnostic station to measure the beam properties will be installed in the system to investigate these effects. Results from numerical and experimental studies are reported in this contribution.
Export • reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)