Journal of Synchrotron Radiation (Nov 2024)

Green upgrading of SPring-8 to produce stable, ultrabrilliant hard X-ray beams

  • Hitoshi Tanaka,
  • Takahiro Watanabe,
  • Toshinori Abe,
  • Noriyoshi Azumi,
  • Tsuyoshi Aoki,
  • Hideki Dewa,
  • Takahiro Fujita,
  • Kenji Fukami,
  • Toru Fukui,
  • Toru Hara,
  • Toshihiko Hiraiwa,
  • Kei Imamura,
  • Takahiro Inagaki,
  • Eito Iwai,
  • Akihiro Kagamihata,
  • Morihiro Kawase,
  • Yuichiro Kida,
  • Chikara Kondo,
  • Hirokazu Maesaka,
  • Tamotsu Magome,
  • Mitsuhiro Masaki,
  • Takemasa Masuda,
  • Shinichi Matsubara,
  • Sakuo Matsui,
  • Takashi Ohshima,
  • Masaya Oishi,
  • Takamitsu Seike,
  • Masazumi Shoji,
  • Kouichi Soutome,
  • Takashi Sugimoto,
  • Shinji Suzuki,
  • Minori Tajima,
  • Shiro Takano,
  • Kazuhiro Tamura,
  • Takashi Tanaka,
  • Tsutomu Taniuchi,
  • Yukiko Taniuchi,
  • Kazuaki Togawa,
  • Takato Tomai,
  • Yosuke Ueda,
  • Hiroshi Yamaguchi,
  • Makina Yabashi,
  • Tetsuya Ishikawa

DOI
https://doi.org/10.1107/S1600577524008348
Journal volume & issue
Vol. 31, no. 6
pp. 1420 – 1437

Abstract

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SPring-8-II is a major upgrade project of SPring-8 that was inaugurated in October 1997 as a third-generation synchrotron radiation light source. This upgrade project aims to achieve three goals simultaneously: achievement of excellent light source performance, refurbishment of aged systems, and significant reduction in power consumption for the entire facility. A small emittance of 50 pm rad will be achieved by (1) replacing the existing double-bend lattice structure with a five-bend achromat one, (2) lowering the stored beam energy from 8 to 6 GeV, (3) increasing the horizontal damping partition number from 1 to 1.3, and (4) enhancing horizontal radiation damping by installing damping wigglers in long straight sections. The use of short-period in-vacuum undulators allows ultrabrilliant X-rays to be provided while keeping a high-energy spectral range even at the reduced electron-beam energy of 6 GeV. To reduce power consumption, the dedicated, aged injector system has been shut down and the high-performance linear accelerator of SACLA, a compact X-ray free-electron laser (XFEL) facility, is used as the injector of the ring in a time-shared manner. This allows the simultaneous operation of XFEL experiments at SACLA and full/top-up injection of the electron beam into the ring. This paper overviews the concept of the SPring-8-II project, the system design of the light source and the details of the accelerator component design.

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