Author: Otake, Y.
Paper Title Page
MOP022 Pulse by Pulse Electron Beam Distribution for Multi-beamline Operation at SACLA 71
  • T. Hara, T. Inagaki, C. Kondo, Y. Otake, H. Takebe, H. Tanaka
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • K. Fukami
    JASRI/SPring-8, Hyogo-ken, Japan
  In order to meet the increasing demand for XFEL user operation, the second undulator beamline (BL2) will be installed during the 2014 summer shutdown at SACLA. Following the installation of BL2, a pulse by pulse electron beam distribution system composed of a kicker and a DC twin-septum magnet, which are currently under development, is planned be installed in January 2015. To distribute the electron beam on a bunch-to-bunch basis, the electron beam is deflected into 0 and ±10 mrad directions at 60 Hz by the kicker, and then the DC twin-septum magnet augments the separation angle to ±50 mrad. The kicker magnet is driven by a 60 Hz trapezoidal waveform and stability less than 30 ppm (peak-peak) has been achieved. This pulse by pulse distribution system will be also used for the beam injection to the upgraded low emittance ring of SPring-8 (SPring-8-II) in future. Since the SPring-8-II storage ring has a small dynamic aperture, low emittance is required for the injection beam. Also the beam injection in parallel with the XFEL operation enables to save the running cost of the injector during top-up operation.  
TUC01 Hard X-ray Self-Seeding Setup and Results at SACLA 603
  • T. Inagaki, N. Adumi, T. Hara, T. Ishikawa, R. Kinjo, H. Maesaka, Y. Otake, H. Tanaka, T. Tanaka, K. Togawa, M. Yabashi
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • S. Goto, Y. Inubushi, T.K. Kameshima, T. Ohata, K. Tono
    JASRI/SPring-8, Hyogo, Japan
  • T. Hasegawa, S. Tanaka
    SES, Hyogo-pref., Japan
  • H. Kimura, A. Miura, H. Ohashi, H. Yamazaki
    Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Hyogo, Japan
  In order to improve the spectral and temporal properties of XFEL, the self-seeding option based on the transmission crystal optics has been implemented in SACLA since 2012. The self-seeding setup composed of four dipole magnets that can generate up to 50 fs temporal delay and a diamond single crystal with the thickness of 180 micro-m has been installed at the position of the 9th undulator segment, which has been moved downstream. In 2013, the installation of all the components has been completed in August and the commissioning has been started in October. After a number of tuning processes such as the beam collimation and undulator K-value optimization, significant spectral narrowing has been confirmed at 10 keV with the C(400) Bragg reflection. The spectral bandwidth of seeded FEL is about 3 eV, which is nearly one order narrower than that of SASE measured without the diamond crystal. The peak spectral intensity of seeded FEL is about 5 times higher than that of SASE. Systematic optimization on beam properties is now in progress towards experimental use of seeded XFELs. This talk gives the overview of the plan, achieved results and ongoing R&D.  
slides icon Slides TUC01 [20.337 MB]  
THP063 Production of C-band Disk-loaded type CG Accelerating Structures 885
  • N. Shigeoka, S. Miura, D. Suzuki
    MHI, Hiroshima, Japan
  • T. Asaka, T. Inagaki, Y. Otake, T. Sakurai
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • H. Ego
    JASRI/SPring-8, Hyogo-ken, Japan
  In April 2013, MITSUBISHI HEAVY INDUSTRIES, LTD. contracted with RIKEN to produce six C-band disk-loaded type and constant gradient (CG) accelerating structures for removal of SCSS. These structures were newly designed by RIKEN for operation with an acceleration gradient of over 45 MeV/m and a repletion rate of 120 pps. The first structure was delivered in August 2013 to RIKEN and the other five was also delivered in March 2014. The accelerating structures were stacked from one hundred accelerating cells and formed by the vacuum brazing method. These cells using oxygen free copper were ultra-precisely machined. Unlike the C-band choke-mode type structures, which MHI manufactured in past for SACLA, the accelerating cells of the CG structure can be tuned after the brazing by pushing dimpling at the tuning hole of each cell. Demands of a VSWR < 1.1 and a phase error < 3 degree are fulfilled after the tuning by using the nodal shift method, which corrects cell frequency shifts due to the machining errors of cells and a cell’s deformation by the heat cycle of the brazing. The detailed results of the production and low-power RF tests will be presented in this presentation.  
poster icon Poster THP063 [0.623 MB]