Study of α-cluster Structure in ²² Mg Using a Radioactive Ion Beam

The α-clusterization of an atomic nucleus has been studied for a long time, even from the earliest days of nuclear physics. Our understanding of the α-cluster structure is, however, mainly limited to the self-conjugate A = 4n (n = 2, 3, 4, · · ·) light nuclei and some of the neutron-rich radionuclides such as ¹⁰ Be, ¹¹ B, and ¹⁴ C. In order to study the α-cluster structure of a neutron-deficient ²² Mg nucleus, we have measured the ¹⁸ Ne(α, α) ¹⁸ Ne scattering in inverse kinematics by using radioactive ¹⁸ Ne beams and the ⁴ He gas target at the Center for Nuclear Study radioactive ion beam separator of the University of Tokyo. Recoiling α particles from the scattering were detected by using silicon strip detectors, which constitute ΔE-E telescopes for particle identification. By adopting a thick target method, we were able to investigate a wide range of excitation energies E _x = 9.9 - 16.5 MeV in ²² Mg in this work.