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Hinode, F.

Paper Title Page
TPPE060 Simulation Study of a Thermionic RF Gun for High Brightness and Short Pulse Beam 3499
 
  • T. Tanaka, H. Hama, F. Hinode, M. Kawai
    LNS, Sendai
  • A. Miyamoto
    HSRC, Higashi-Hiroshima
  • K. Shinto
    Tohoku University, Sendai
 
  Characteristics of thermionic RF guns are not understood completely. In particular, measured intense beam emittances extracted from thermionic RF guns do not agree well with simulated values so far. Most of simulation codes solve the equation of electron motion in an intrinsic mode of the RF field calculated by a separated code. The way of such simulation codes is not self-consistent completely. That is probably a major reason for the discrepancy between the experiments and the simulations. One of the other way for a self-consistent simulation codes is to use an FDTD (Finite Difference Time Domain) method. Since the FDTD method can take into account the microwave propagation including the space charge effect and the beam loading self-consistently, we have developed an FDTD code as 3-D Maxwell's equation solver and applied for a study of beam dynamics in a thermionic RF gun. The main purpose of simulaiton study is to obtain overall properties of the beam dynamics at the time. The goal of this simulation study of the thermionic RF gun is to understand correct characteristics of the thermionic RF gun for producing high brightness and short pulse beam.  
FPAE025 Study of Slow Beam Extraction Through the Third Order Resonance with Transverse Phase Space Manipulation by a Mono-Frequency RFKO 1892
 
  • A. Miyamoto, H. Hama, F. Hinode, M. Kawai, K. Shinto, T. Tanaka
    LNS, Sendai
 
  An electron pulse-stretcher ring (STB ring) has a function which converts a pulse beam generated by RF linac into a quasi-continuous beam. Circulating beam in the ring is extracted by the third order resonance. Since there is no accelerating field in the ring, the beam approaches a transverse resonance condition due to synchrotron radiation loss with finite chromaticity. The extracted beam from the ring has some spread in time and space corresponding to injected beam from linac even if the injected beam is perfectly matched to the ring optics. However, the extracted beam emittance can be reduced by applying a phase space manipulation using an RF shaker. Under the influence of perturbation using an RF shaker driven by a mono-frequency, the betatron amplitude of circulating beam can be controlled in order to reduce the extracted beam emittance. The experimental results will be reported in this conference.  
FPAE036 Lattice Modification of a 1.2 GeV STB Ring for Generation of High Energy Gamma-Rays Using Internal Target Wire 2458
 
  • F. Hinode, H. Hama, M. Kawai, A. Kurihara, A. Miyamoto, M. Mutoh, M. Nanao, Y. Shibasaki, K. Shinto, S. Takahashi, T. Tanaka
    LNS, Sendai
 
  A 1.2 GeV Stretcher-Booster Ring (STB ring) has been routinely operated at Laboratory of Nuclear Science (LNS), Tohoku University. The STB ring has functions of a pulse-beam stretcher and a booster-storage ring. In the booster-storage operation, high energy gamma-ray beam generated via bremsstrahlung from internal target wire is utilized for experiments of nuclear physics. Some fractions of circulating electrons are also deflected in the target wire due to Coulomb scattering without significant loss of the energy. The scattered electrons that are not getting out of the dynamic aperture once can circulate in the ring. Such electrons, however, would hit the chamber walls and supports of the target wire during further turns, because they have very large betatron amplitude. Consequently the Coulomb scattered electrons must be a source of significant background and may cause a degradation of gamma-ray beam quality. The quality of the gamma-ray beam has been improved by modifying the lattice functions of the ring, and we report the improvement in this conference.