Author: Shintake, T.
Paper Title Page
MOOA4
 Fist Lasing of SACLA  
 
  • T. Shintake
    RIKEN Spring-8 Harima, Hyogo, Japan
  
  On June 7 2011, we observed the first lasing X-ray at 1.2 Angstrom in our new X-ray FEL (SACLA) in Japan. The construction project, previously called XFEL/Japan, started in 2006 at SPring-8, spending four and half years for civil construction, fabrication of hardware components, installation and another half year for high power processing and debugging, then completed in March 2011. After three-month beam commissioning and tuning, we tried lasing at 7.1 GeV, by sending beam into the undulator line. We slowly closed undulator gaps from upstream, when we came to 8th undulator, we firstly observed a bright spot on YAG-screen in a middle of spontaneous radiation. Using whole undulators (sixteen of 5 m each), the power reached to 20 μJ/pulse at 30 fsec with 3 kA beam. The FEL power has not yet reached to its saturation level. We currently tuning whole machine, and preparing for X-ray experiments from this autumn run. The accelerator construction itself was a big project and tremendous effort was made by Joint Construction Team (JASRI+RIKEN) and a large number of industry people. We would like to thank all contributors and all friends in FEL community.  
slides icon Slides MOOA4 [3.858 MB]  
 
THPA29 Performance of the RF Cavity BPM at XFEL/SPring-8 “SACLA” 539
 
  • H. Maesaka, T. Ohshima, Y. Otake
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • H. Ego, S. Matsubara
    JASRI/SPring-8, Hyogo-ken, Japan
  • S.I. Inoue
    SES, Hyogo-pref., Japan
  • T. Shintake
    RIKEN Spring-8 Harima, Hyogo, Japan
  
  We have developed an rf cavity beam position monitor (RF-BPM) for the XFEL facility at SPring-8, “SACLA”. The demanded position resolution of the BPM is less than 1 μm, because an electron beam and X-rays must be overlapped with 4 μm precision in the undulator section. To achieve this requirement, we employed a C-band RF-BPM that has a resonant frequency of 4760 MHz. The RF-BPM has a TM110 dipole mode resonator for position detection and a TM010 monopole mode resonator for phase reference and charge normalization. Rf signals from the RF-BPM are detected by IQ (In-phase and Quadrature) demodulators and the detected signals are recorded by 238 MHz waveform digitizers. The position resolution was confirmed to be 0.2 μm by using a 250 MeV electron beam at the SCSS test accelerator. Then, 57 RF-BPMs were produced and installed into SACLA. The beam tuning of SACLA started in February 2011 and the RF-BPM system has been working well. We report the basic performance such as a resonant frequency, a Q factor, machining accuracy etc. for each cavity and the achieved position resolution of the RF-BPM system.  
 
MOOBI2 High Harmonics from Gas, a Suitable Source for Seeding FEL from the Vacuum-ultraviolet to Soft X-ray Region 9
 
  • G. Lambert, J. Gautier, V. Malka, A. Sardinha, S. Sebban, F. Tissandier, B. Vodungbo, P. Zeitoun
    LOA, Palaiseau, France
  • B. Carré, D. Garzella
    CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
  • O.V. Chubar, M.-E. Couprie, M. Labat
    SOLEIL, Gif-sur-Yvette, France
  • M. Fajardo
    IPFN, Lisbon, Portugal
  • T. Hara
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • C.P. Hauri
    Paul Scherrer Institut, Villigen, Switzerland
  • H. Kitamura, T. Shintake
    RIKEN/SPring-8, Hyogo, Japan
  • J. Lüning
    CCPMR, Paris, France
  • Y.T. Tanaka
    JASRI/SPring-8, Hyogo-ken, Japan
  • T. Tanikawa
    PhLAM/CERCLA, Villeneuve d'Ascq Cedex, France
  
  FEL have been recently evolving very fast in the extreme-ultraviolet to soft X-ray region. Once seeded with high harmonics generated in gas, these light sources deliver amplified emissions with properties which are, for most of them, directly linked to the injected harmonic beam, e.g. the ultrashort pulse duration for FEL and the high temporal and spatial degree of coherence. Since the last two years the developments of techniques for improving the harmonic properties for seeding FEL lead to major results on tunability, intensity, repetition rate and polarization. Actually harmonics are nowadays used for numbers of applications, before limited to FEL facility. Also, FEL based on harmonic seeding can benefit from the natural synchronization between the FEL, the harmonic and the laser used for generation, which makes it a perfect candidate for pump-probe experiment with fs resolution.  
slides icon Slides MOOBI2 [1.782 MB]