Abstract :
Recent studies of shell structures of nuclei far from the stability line are presented. In particular studies with RI beams such as interaction cross sections, fragments momentum distributions reveal new dynamic change of shell structure. Special attention is paid on neutron halo nuclei in the p-sd shell. In halo nuclei and other neutron rich nuclei, the2s1/2 orbital shows irregular behavior. One such extreme case is the new neutron magic numberN=16. The global behavior of2s1/2 shell is discussed also in relation to the interaction cross-sections and fragment momentum distributions.
