Centers & Labs

RIKEN Nishina Center for Accelerator-Based Science


Team Leader: Masanori Wakasugi (D.Sci.)
Masanori  Wakasugi(D.Sci.)

We aim at the investigation of internal nuclear structure of short-lived radioactive nuclei (RI) by means of electron scattering. Electron scattering for RI's has never been performed duo to inability to make target of these nuclei. An electron-RI collider system, which requires a huge accelerator complex, has so far been unique solution to overcome the difficulty. We have developed a novel internal target system named SCRIT (Self-Confining RI Ion Target) in an electron storage ring to make the experiment easier with much compact experimental system. Construction of the SCRIT electron scattering facility wa started in 2009, and operation of electron accelerators, RTM and SR2, was started in 2010. Test experiments of the SCRIT system equipped in SR2 were performed in 2011-2012 to evaluate the SCRIT performances. The luminosity was reached to 10^27/(cm^2s) in case of 10^8 ions injection, and the confinement lifetime was over 1s. Therse are performances satisfactory to the electron scattering experiment. On the other hand, an ISOL type of RI generator (ERIS) in now developing. ERIS was constructed in 2011 and commissioned in 2012. In 2015, the construction of the detector system for scattered electrons are completed and it has been commissioned. In 2016, we succeeded in measurements of the momentum transfer distribution of the scattered electrons from 132Xe isotopes and in determination of the nuclear charge density distribution. We are now preparing the first experiment for unstable nuclei.

Main Research Field

Mathematical and physical sciences


  • Accelerator science
  • Nuclear physics
  • Electron scattering
  • Nuclear mass measurement

Selected Publications

  1. K. Tsukada et al.:
    "First elastic electron scattering from 132Xe at the SCRIT facility"
    Phys, Rev. Lett., to be published.
  2. T. Suda and H. Simon.:
    "Prospect for electron scattering on unstable, exotic nuclei"
    Nucl. Instrum, Meth. A, in press.
  3. T. Onisji et al.:
    "The SCRIT electron scattering facility at the RI beam factory"
    Phys. Scr. T166, 014071 (2015).
  4. M. Wakasugi et al.:
    "Construction of the SCRIT electron scattering facility at the RIKEN RI Beam Factory"
    Nucl. Instrum. Meth., B317, 668-673 (2013).
  5. T. Ohnishi et al.:
    "Electron-beam-driven RI separator for SCRIT (ERIS) at RIKEN RI beam factory"
    Nucl. Instrum. Meth., B317, 357-360 (2013).
  6. R. Ogawara et al.:
    "Ion-trapping properties of SCRIT"
    Nucl. Instrum. Meth., B317, 674-678 (2013).
  7. T. Suda et al.:
    "Nuclear Physics at the SCRIT electron scattering facility in RIBF"
    Prog. Theo. Exp. Phys., 03(2012), C008 (2012).
  8. T.Suda et al.:
    "First Demonstration of Electron Scattering usin a Novel Ion-Trap Target Developed for Short-Lived Nuclei"
    Phys. Rev. Letter, 102, 102501 (2009).
  9. M.Wakasugi et al.:
    "Electron Scattering Based on Novel Internal Target Technique SCRIT"
    Eur. Phys. J., A42, 453 (2009).

Lab Members

Principal Investigator

Masanori Wakasugi
Team Leader

Core Members

Masamitsu Watanabe
Senior Research Scientist
Tetsuya Ohnishi
Senior Technical Scientist
Takeshi Maie
Nishina Center Technical Scientist
Akitomo Enokizono
Contract Researcher

Contact information

2-1 Hirosawa,
Wako, Saitama
351-0198, Japan

Email: wakasugi [at]

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