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. We have finished the installation of a SCRIT device into the SR2 in last year. Test experiment of SCRIT electron scattering using stable Cs isotope has been performed, and it was found that collision luminosity between electron beam and target Cs ions trapped in the SCRIT device exceeds 10^27 /(cm2s) at the electron beam current of 200 mA. An RI ion source and an ISOL system has been constructed and test experiment using stable Xe isotopes. Overall extraction efficiency was found to be 21 % and mass resolution (M/ΔM) of ISOL system was achieved to be 1600. We plan to start RI production at the ISOL system in 2012.

Research Subject

Developement of the SCRIT technology and electron scattering for unstable nuclei

List of Selected Publications

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