Medium to high spin spectroscopy of A = 30 - 40 neutron-rich nuclei at JAEA

Motivated by the recent progress in the RI-beam physics and the discovery of the island of inversion, a systematic investigation of the medium to high spin excited states in neutron-rich A = 30 $\sim$ 40 region has been underway as a cooperative study at the JAEA tandem accelerator facility. Since the evolution of shell structure is a function of nuclear deformation and rotation as well as the isospin, systematic understanding of the levels in this neutron-rich region is of great interest. Especially, the systematic identification of the high-spin levels involving the {sd} to {fp} cross-shell excitation could be a key to clarify the evolution of N = 20 neutron shell gap. We will present recent results on some neutron rich nuclei in this mass region and disscuss their shell structure.