Author: Honda, Y.
Paper Title Page
MOPPP035 Initial Emittance and Temporal Response Measurement for GaAs Based Photocathodes 640
  • S. Matsuba
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
  • Y. Honda, T. Miyajima, T. Uchiyama, M. Yamamoto
    KEK, Ibaraki, Japan
  • X.G. Jin
    Institute for Advanced Research, Nagoya, Japan
  • Y. Takeda
    Nagoya University, Nagoya, Japan
  For future light source based on Energy Recovery Linac (ERL) is planned in KEK. For the ERL, an ultra low emittance and fast temporal response and high current electron source is needed. To achieve these requirements, a high voltage DC gun with a Negative Electron Affinity photo-cathode is under development. In this development, it is important to investigate the performance of photo-cathodes. We have constructed an ERL gun test stand to measure emittance and temporal profile. We use a solenoid scan technique for emittance measurements and a deflecting cavity technique for temporal profile measurements. In this presentation, we introduce KEK ERL gun test stand and beam test results.  
TUPPD056 Development of a Photo-injector Laser System for KEK ERL Test Accelerator 1530
  • Y. Honda
    KEK, Ibaraki, Japan
  As a test accelerator for future light source, Compact Energy Recovery Linac has been constructed in KEK. For its photo-injector, we have been developing a laser system. It requires high repetition rate and high average power at a visible wavelength. Development of an high power fiber amplifier and high efficiency wavelength conversion system utilizing an optical cavity will be reported.  
TUPPP016 Recent Development of PF Ring and PF-AR 1641
  • Y. Tanimoto, T. Aoto, S. Asaoka, K. Endo, K. Haga, K. Harada, T. Honda, Y. Honda, M. Izawa, Y. Kobayashi, A. Mishina, T. Miyajima, H. Miyauchi, S. Nagahashi, N. Nakamura, T. Nogami, T. Obina, T. Ozaki, C.O. Pak, H. Sakai, S. Sakanaka, H. Sasaki, Y. Sato, K. Satoh, M. Shimada, K. Shinoe, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, R. Takai, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, M. Yamamoto
    KEK, Ibaraki, Japan
  • H. Takaki
    ISSP/SRL, Chiba, Japan
  After the earthquake of March 11, two light sources of KEK, PF ring and PF-AR, have recovered the regular operation from October, 2011. We installed tandem variably-polarized undulators at PF ring in 2009. Recently, the orbit switching system has been completed with sufficient feed-forward orbit compensation at 10-Hz. PF ring is usually operated at 450 mA with a top-up injection using the pulsed sextupole magnet instead of the conventional kicker magnets. The transverse and longitudinal instabilities are suppressed by a digital feedback system using the iGp signal processor. In the longitudinal direction, we observed unstable quadrupole mode oscillation which could not be controlled by the feedback system. We had applied the phase modulation of the main RF cavity to stabilize the quadrupole oscillation before. Old-type RF-shielded gate valves damaged by the earthquake were removed from the ring during the summer maintenance. In the operation after autumn, the quadrupole oscillation can be cured by dividing the bunch train of partial-filling. Without the phase modulation, the effective brightness of SR beam has been improved especially at beam lines of finite dispersion function.  
WEOBB02 Refraction Contrast Imaging via Laser-Compton X-Ray Using Optical Storage Cavity 2146
  • K. Sakaue, T. Aoki, M. Washio
    RISE, Tokyo, Japan
  • M.K. Fukuda, Y. Honda, N. Terunuma, J. Urakawa
    KEK, Ibaraki, Japan
  We have been developing a pulsed-laser storage technique in a super-cavity for a compact x-ray sources. The pulsed-laser super-cavity enables to make high peak power and small waist laser at the collision point with the electron beam. Recently, using 357 MHz mode-locked Nd:VAN laser pulses which stacked in a super-cavity scattered off a multi-bunch electron beam, we obtained a multi-pulse x-rays through the laser-Compton scattering. Then, we performed a X-ray imaging via laser-Compton X-ray. The images have edge enhancement by refraction contrast because the X-ray source spot size was small enough. This is one of the evidences that laser-Compton X-ray is high quality. Our laser-Compton experimental setup, the results of X-ray imaging and future prospective will be presented at the conference.  
slides icon Slides WEOBB02 [4.393 MB]  
WEPPD055 Gamma-rays Generation with 3D 4-mirror Cavity for ILC Polarized Positron Source 2645
  • T. Akagi, S. Miyoshi
    Hiroshima University, Graduate School of Advanced Sciences of Matter, Higashi-Hiroshima, Japan
  • S. Araki, Y. Funahashi, Y. Honda, T. Okugi, T. Omori, H. Shimizu, N. Terunuma, J. Urakawa
    KEK, Ibaraki, Japan
  • H. Kataoka, T. Kon
    Seikei University, Japan
  • M. Kuriki, T. Takahashi
    Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
  • K. Sakaue, M. Washio
    RISE, Tokyo, Japan
  • R. Tanaka, H. Yoshitama
    Hiroshima University, Higashi-Hiroshima, Japan
  We are conducting gamma-rays generation experiment by the laser-Compton scattering using a Fabry-Perot cavity. We developed a 3D 4-mirror cavity, and it is installed at the KEK-ATF. By using a 3D 4-mirror cavity, small laser spot can be achieved with stable resonant condition. In addition, we aim 1900 times enhancement of input laser power by a 4-mirror cavity to increase the number of gamma-rays.  
WEPPP018 A New Beam Injection Scheme for a Compact Low-energy Storage Ring 2761
  • Y. Honda
    KEK, Ibaraki, Japan
  A very compact storage ring at low energy has an unique application such as Compton X-ray source. Scheme for efficient injection is an issue for such a compact storage ring. Utilizing a phase-shift in the non-relativistic energy region, a new idea for accumulating the incoming bunch on an already circulating bunch without any kicker or orbit bump has been presented. Its applicable parameter range will be presented.