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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

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