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The world’s most powerful X-ray laser beam

Focusing X-ray lasers to 1 um size by atomically precise mirrors


Graduate School of Engineering / Faculty of Engineering

The SPring-8 Angstrom Compact Free Electron Laser (SACLA), located at Harima in Hyogo Prefecture, can produce full coherent lasers at wavelengths shorter than 1 angstrom. This facility will help to reveal unknown atomic structures of important proteins and time-dependent structural changes of materials under extreme pressure conditions. To perform these experiments, it is necessary to further increase the intensity density of XFEL beams by focusing multiple beams on a single point.

Application field of focused X-ray free electron laser pulse © Hirokatsu Yumoto (JASRI)
The newly-developed XFEL focusing system which can produce extremely intensive X-ray pulses will open new frontiers in science

Dr. Hirokatsu Yumoto at Japan Synchrotron Radiation Institute, Professor Kazuto Yamauchi at Osaka University, Associate Professor Hidekazu Mimura at Department of Precision Engineering Graduate School of Engineering, The University of Tokyo, Group Director Dr. Yabashi Makina at RIKEN and their colleagues successfully fabricated ultraprecise X-ray mirrors with atomic-level accuracy and installed them to SACLA. The researchers performed focusing XFEL tests and realized a one micrometer size beam for the first time, achieving an intensity density of 6×1017W/cm2, currently the most intense value achieved anywhere in the world.

Research using the imaging system with the focused XFEL beam has already started to clarify the structures of single-celled creatures and the structure of proteins at atomic resolution. This research will be invaluable in determining the causes of diseases and in the development of new drugs.

Press release


Hirokatsu Yumoto, Hidekazu Mimura, Takahisa Koyama, Satoshi Matsuyama, Kensuke Tono, Tadashi Togashi, Yuichi Inubushi, Takahiro Sato, Takashi Tanaka, Takashi Kimura, Hikaru Yokoyama, Jangwoo Kim, Yasuhisa Sano, Yousuke Hachisu, Makina Yabashi, Haruhiko Ohashi, Hitoshi Ohmori, Tetsuya Ishikawa, Kazuto Yamauchi,
“Focusing of X-ray free electron laser pulses with reflective optics”,
Nature Photonics Online Edition: 2012/12/17 (Japan time), doi: 10.1038/nphoton.2012.306.
Article link


Graduate School of Engineering

Department of Precision Engineering, Graduate School of Engineering

Kunieda-Mimura group, Department of Precision Engineering, Graduate School of Engineering (Japanese)



Material Fabrication Laboratory, RIKEN Advanced Science Institute

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