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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. Tanaka and A. Kagamihata.:
    "Thermal demagnetization in in-vacuum undulators and effect of magnetic configuration on choice of magnet grade"
    Nuclear Instruments and Methods in Physics Research Section A, 165112 (2021)
  • 2. T. Tanaka, Y. Kida, R. Kinjo et al.:
    "Development of an undulator with a variable magnetic field profile"
    Journal of Synchrotron Radiation 28, 404–409 (2021)
  • 3. P. R. Ribic and T. Tanaka.:
    "Isolated single-cycle extreme-ultraviolet pulses from undulator radiation"
    Opt. Lett. 45, 5234–5237 (2020)
  • 4. R. Kinjo and T. Tanaka.:
    "Undulator configuration for helicity switching in in-vacuum undulators"
    Phys. Rev. Accel. Beams 23, 020705 (2020)
  • 5. T. Tanaka.:
    "Electron bunch compression with an optical laser"
    Phys. Rev. Accel. Beams 22, 110704 (2019)
  • 6. T. Tanaka and P. R. Ribic.:
    "Shortening the pulse duration in seeded free-electron lasers by chirped microbunching"
    Opt. Express 27, 30875–30892 (2019)
  • 7. T. Tanaka and A. Kagamihata.:
    "Demonstration of high-performance pole pieces made of monocrys- talline dysprosium for short-period undulators,”
    Journal of Synchrotron Radiation 26, 1220–1225 (2019)
  • 8. T. Tanaka.:
    "Universal representation of undulator phase errors"
    Phys. Rev. Accel. Beams 21, 110704 (2018)
  • 9. 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
  • 10. T. Tanaka.:
    "Difference frequency generation in free electron lasers"
    Opt. Lett. 43, 4485 (2018)

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
Extension: 3806
Email: ztanaka [at] spring8.or.jp