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RIKEN SPring-8 Center Advanced X-Ray Laser Group

Group Director: Takashi Tanaka (D.Eng.)

Research Summary

Takashi  Tanaka(D.Eng.)

The mission of Advanced X-ray Laser Group 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 Fields

  • Interdisciplinary Science & Engineering

Related Research Fields

  • Mathematical & Physical Sciences
  • Engineering
  • Quantum Beam Science
  • Applied Physics
  • Integrated Engineering


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

Selected Publications

  • 1.T. Bizen, R. Kinjo and T. Tanaka.:
    "Enhancing the radiation resistance of undulator permanent magnets by tilting the easy axis of magnetization"
    Phys. Rev. Lett. 121, 124801 (2018) 4
  • 2.T. Tanaka.
    "Difference frequency generation in free electron lasers"
    Opt. Lett. 43, 4485 (2018)
  • 3.T. Tanaka.
    "Numerical methods for free electron laser simulations"
    Journal of Electromagnetic Waves and Applications 32, 371 (2018)
  • 4.R. Kinjo, A. Kagamihata, T. Seike et al.:
    "Lightweight-compact variable-gap undulator with force cancellation system based on multipole monolithic magnets"
    Review of Scientific Instruments 88, 073302 (2017)
  • 5.T. Tanaka and R. Kinjo:
    "High gain harmonic generation free electron lasers enhanced by pseudoenergy bands"
    Phys. Rev. Accel. Beams 20, 080706 (2017)
  • 6.T. Tanaka.
    "Current status and future perspectives of accelerator-based x-ray light sources"
    Journal of Optics 19, 093001 (2017)
  • 7.T. Tanaka:
    "Coherent mode decomposition using mixed Wigner functions of Hermite--Gaussian beams"
    Optics Letters 42, 1576 (2017)
  • 8.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)
  • 9.T. Bizen et al.:
    "Radiation-induced magnetization reversal causing a large flux loss in undulator permanent magnets"
    Scientific Reports 6, 37937 (2016)
  • 10.T. Tanaka:
    "Reducing the group velocity of coherent radiation for upconverting the single-cycle electron density modulation"
    Applied Physics Letters 108, 061106 (2016)

Recent Research Results

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] spring8.or.jp