Invariant mass spectroscopy of neutron-rich nuclei with large acceptance spectrometer SAMURAI

SAMURAI magnetic spectrometer was constructed in RIBF facility, RIKEN, aiming at providing spectroscopic studies using radioactive isotope secondary beam with inverse kinematics.  Variety of detector devices[1] upstream and downstream of SAMURAI magnet enable us to perform kinematically complete measurement by detecting multiple particles emitted on the reaction in coincidence.

Since the start of SAMURAI experiment in 2012, a number of and variety of experiments have been carried out.  Within them, spectroscopic studies by invariant mass measurements are one of the main topics, which are effectively pursued by broadband and large angular acceptance magnetic spectrometer.
So far, a number of coincidence experiments with heavy ions(HI) and neutrons have performed around oxygen isotope[2] in early stage and they have been extended to Ne or Mg isotopes recently.
Furthermore, Coulomb dissociation studies has been performed up to Ca isotopes, and also several reactions of ⁷⁹Se and ⁹³Zr, long lived fission product isotopes, have been measured for interest of nuclear data activities.

In the presentation, the series of experimental results of invariant mass spectroscopy will be reviewed and the detail of the devices will be given which have realized such spectroscopic studies.  Near future plans within several years will be also mentiooned. 


[1] T. Kobayashi, et. al.,Nucl. Instr. Meth B 317 (2013) 294
[2] Y. Kondo, et. al., Phys. Rev. Lett. 116 (2016) 102503