Centers & Labs

RIKEN Nishina Center for Accelerator-Based Science

Radioactive Isotope Physics Laboratory

Chief Scientist: Hiroyoshi Sakurai (D.Sci.)
Hiroyoshi  Sakurai(D.Sci.)

This Laboratory conducts programs at “RI Beam Factory (RIBF)”, and explores exotic nuclear structures and dynamics in exotic nuclei with largely imbalanced proton and neutron numbers. Our aim is to develop new experimental techniques utilizing fast radioactive isotope beams at RIBF, to discover new phenomena and properties in exotic nuclei. The Laboratory is focusing three major subjects; shell evolution of very neutron-rich nuclei, the r-process path and equation-of-state in asymmetric nuclear matter. The Laboratory has initiated international collaborations for in-beam gamma spectroscopy, decay spectroscopy and heavy-ion induced reactions, and has formed a discussion forum for next generation gamma detectors.

Main Research Field

Mathematical and physical sciences

Related Research Fields

Interdisciplinary science and engineering


  • Radioactive Isotope Beam
  • Exotic Nuclei
  • Gamma Spectroscopy
  • Heavy-ion induced Reactions

Selected Publications

  1. Wang H., Otsu H., Sakurai H., et al.:
    "Spallation reaction study for fission products in nuclear waste: Cross section measurements for Cs-137 and Sr-90 on proton and deuteron"
    Phys. Lett. B 754, 104-108 (2016)
  2. Shane R., McIntosh A.B., Isobe T., et al.:
    "S pi RIT: A time-projection chamber for symmetry-energy studies"
    Nucl. Instrum. Methods A 784, 513-517 (2015)
  3. Lorusso G., Nishimura S., et al:
    "beta-Decay Half-Lives of 110 Neutron-Rich Nuclei across the N=82 Shell Gap: Implications for the Mechanism and Universality of the Astrophysical r Process"
    Phys. Rev. Lett. 114, 192501 (2015)
  4. Steppenbeck D., et al.
    "Evidence for a new nuclear 'magic number' from the level structure of Ca-54"
    Nature 502, 207 (2013)
  5. Nishimura S., Li Z, Watanabe H., Yoshinaga K, et al.:
    "Beta-Decay Half-Lives of Very Neutron-Rich Kr to Tc Isotopes on the Boundary of the r-Process Path: An Indication of Fast r-Matter Flow"
    Phys. Rev. Lett. 106, 052502 (2011)
  6. Doornenbal P, Scheit H, Aoi N, Takeuchi S, et al.:
    "Spectroscopy of Ne-32 and the "Island of Inversion""
    Phys. Rev. Lett. 103, 152503 (2009)
  7. Suzuki D., Iwasaki H., Otsu H., et al.:
    "Breakdown of the Z=8 Shell Closure in Unbound O-12 and its Mirror Symmetry"
    Phys. Rev. Lett. 103, 152503 (2009)
  8. Ong, H. J., Imai, N., Suzuki D., Iwasaki H., Sakurai H., Onishi T.K., Suzuki M.K., Ota S., Takeuchi S., Nakao T., et al.:
    "Lifetime measurements of first excited states in C-16, C-18"
    Physical Review C 78, 014308 (2008)
  9. Yoneda K., Sakurai H. et al.:
    "Deformation of 34Mg studied via in-beam -ray spectroscopy using RI beam fragmentation"
    Physics Letters B 499, 233-237 (2001).
  10. Sakurai, H., Lukyanov, S.M., Notani, M., Aoi, N., Beaumel, D., Fukuda, N., Hirai, M., Ideguchi, E., Imai, N., Ishihara, M., Iwasaki, H., Kubo, T., Kusaka, K., Kumagai, H., Nakamura, T., Ogawa, H., Penionzhkevich, Yu.E., Teranishi, T., Watanabe, Y.X., Yone.:
    "Evidence for particle stability of 31F and particle instability of 25N and 28O"
    Physics Letters B 448, 180-184 (1999).

Lab Members

Principal Investigator

Hiroyoshi Sakurai
Chief Scientist

Core Members

Takashi Ichihara
Vice Chief Scientist
Shunji Nishimura
Senior Research Scientist
Yoichi Nakai
Senior Research Scientist
Akihisa Kohama
Senior Research Scientist
Tadaaki Isobe
Senior Research Scientist
Daisuke Suzuki
Research Scientist
Pieter Christiaan Doornenbal
Research Scientist
He Wang
Foreign Postdoctoral Researcher
Paer-Anders Soederstroem
Foreign Postdoctoral Researcher
Mizuki Nishimura
Contract Researcher
David Steppenbeck
Contract Researcher

Contact information

Nishina RIBF Bldg.,
2-1 Hirosawa,
Wako, Saitama
351-0198, Japan

Email: sakurai [at]

Related links

Recent research results