Seminar Details

Breakup Reaction Experiments at the New-Generation RI Beam Facility RIBF at RIKEN

Takashi Nakamura, Tokyo Institute of Technology
Wednesday, March 20, 4:10 PM - Nuclear Science Seminar
NSCL Lecture Hall

RIBF(RI beam factory) at RIKEN started its operation as a new-generation rare isotope beam facility in 2007. Since then it has provided a wide variety of experimental opportunities to explore the nuclei far from the stability. In this facility, heavy ions up to 238U can be accelerated at 345 MeV/nucleon with high intensity. For instance, intensity over 200 pnA for 48Ca beam has reached in 2012. In this seminar, I primarily present the results of the Coulomb and nuclear breakup experiments on very neutron rich nuclei from C to Si isotopes, using the high intense RI beams produced from the 48Ca beam. Coulomb breakup, which is dominated in the reaction with a high-Z target such as Pb, is sensitive to the neutron halo state because of the large electric dipole strength at low excitation energies, called soft E1 excitation. On the other hand, nuclear breakup, which is primarily induced in a reaction with a light target such as C, is a tool to probe a single particle state of a removed nucleon. I first show the inclusive Coulomb and nuclear breakup results, where 1) the change of the shell structure in the neutron rich nuclei near N=20 and N=28, and 2) the halo states in 22C, 31Ne, and 37Mg are found. I also demonstrate that the combined analysis of using these two breakup reactions is useful. In the second part, I will show the kinematically complete measurement of 19B, 22C Coulomb breakup, and some other breakup reactions performed at the SAMURAI facility, which is equipped with 3T large acceptance superconducting magnet and the large acceptance neutron detector array NEBULA. This facility has just commisioned in March, 2012. Finally I will show some future perspectives about breakup reactions and possible applications at the new-genaration RI beam facility. [1] T.Nakamura et al., Phys. Rev. Lett. 103, 262501 (2009). [2] N.Kobayashi, T.Nakamura et al., Phys. Rev. C 86, 054604 (2012). [3] T.Nakamura, Y. Kondo, p67-p119, Clusters in Nuclei Vol. 2 (Lecture Notes in Physics Vol. 848) ed C.Beck (Berlin: Springer) (2012).