利用直接核反应研究轻丰中子核的奇特结构

Studies on the exotic structure of neutron-rich nuclei via direct reactions

直接核反应是研究丰中子区核结构的重要手段.我们发展了质子标记的敲出反应实验方法,并用于6He和8He的结构研究,给出了7He共振态至今最精确的测量结果.发展了多中子关联测量技术,并基于此重建了8He激发态以及研究了8He中的双中子关联.通过12Be的非弹散射实验,观测到若干共振态,构成6He+6He和4He+8He两条分子转动带,支持12Be的-4n-集团结构.

Direct reaction is particularly useful in studying the nuclear structure of neutron-rich nuclei. By the use of the recoiled proton tagging technique, knockout reaction was developed into a clean spectroscopic probe and was applied to the study of the exotic structures of 6He and SHe. The most accurate parameters and related spectroscopic factor was obtained for the ground state of 7He. The Multi-neutron detection technique was also implemented, with which the resonant states of 8He and the corresponding neutron-neutron correlation function were measured. The cluster structure of 12Be was studied via inelastic excitation followed by coincidently recording the decay products, and molecular-like resonant states were observed for a -SHe and ^6He-^6He decaying channels. These states are part of the molecular rotational bands and therefore clearly support the highly clustering structure of 12Be.