Centers & Labs

RIKEN SPring-8 Center

Advanced X-Ray Laser Group

Group Director: Takashi Tanaka (D.Eng.)
Takashi  Tanaka(D.Eng.)

The mission of Advanced X-ray Laser Laboratory is to upgrade the light source performance of SACLA (XFEL: X-ray free electron laser facility) and SPring-8 (large-scale SR: synchrotron radiation facility), which are in operation in RIKEN SPring-8 Center (RSC). We are developing magnetic devices called undulators, which produce intense X-ray laser and highly brilliant SR by deflecting the high energy electron beam. We also explore more advanced XFEL and SR concepts that will open up a new possibility of X-ray science. By promoting these R&Ds, we pursue the goal of enhancing the light source performances of SACLA and SPring-8, and establish an “ultimate X-ray laser facility” in RSC, which eventually leads to creation of a new field of photon science exploiting X-ray lasers.

Main Research Field

Interdisciplinary science and engineering

Related Research Fields

Mathematical and physical sciences / Engineering


  • free electron laser
  • synchrotron radiation
  • undulator
  • simulation
  • permanent magnet

Selected Publications

  1. T. Tanaka:
    "Coherent mode decomposition using mixed Wigner functions of Hermite--Gaussian beams"
    Optics Letters 42, 1576 (2017)
  2. Y. Kida, R. Kinjo and T. Tanaka:
    "Synthesizing high-order harmonics to generate a sub-cycle pulse in free-electron lasers"
    Applied Physics Letters 109, 151107 (2016)
  3. R. Kinjo and T. Tanaka:
    "Spectrum splitting for fast polarization switching of undulator radiation"
    Journal of Synchrotron Radiation 23, 751 (2016)
  4. T. Bizen et al.:
    "Radiation-induced magnetization reversal causing a large flux loss in undulator permanent magnets"
    Scientific Reports 6, 37937 (2016)
  5. T. Tanaka et al.:
    "Using irregularly spaced current peaks to generate an isolated attosecond X-ray pulse in free-electron lasers"
    Journal of Synchrotron Radiation 23, 1273 (2016)
  6. T. Tanaka:
    "Reducing the group velocity of coherent radiation for upconverting the single-cycle electron density modulation"
    Applied Physics Letters 108, 061106 (2016)
  7. R. Kinjo, T. Bizen, and T. Tanaka:
    "Undulator Development for SPring-8-II"
    Synchrotron Radiation News 28, 45 (2015)
  8. T. Tanaka:
    "SIMPLEX: simulator and postprocessor for free-electron laser experiments"
    Journal of Synchrotron Radiation 22, 1319 (2015)
  9. T. Tanaka:
    "Proposal to generate an isolated monocycle X-ray pulse by counteracting the slippage effect in free-electron lasers"
    Physical Review. Letters 114, 044801 (2015)
  10. T. Tanaka:
    "Numerical methods for characterization of synchrotron radiation based on the Wigner function method"
    Physical Review ST-AB 17, 060702 (2014)

Lab Members

Principal Investigator

Takashi Tanaka
Group Director

Core Members

Ryota Kinjo
Research Scientist

Contact information

Structural Biology Facility 311,
1-1-1 Kouto, Sayo-cho, Sayo-gun
Hyogo 679-5148, Japan
Tel: +81-(0)791-58-0802

Email: ztanaka [at]

Related links