丰中子超重核素分离关键技术

自1960年代以来，理论预言以质子数114（120或126）、中子数184（或172等）为中心存在 “超重核稳定岛”。合成稳定岛上核素并研究其性质，将揭示在极强库仑场下原子核的结构和性质、发现可能存在的最大核幻数。攀登“超重核稳定岛”是人类的科学梦想之一。国内外正在兴建新一代强流重离子加速器装置，使利用重锕系核弹靶系统通过多核子转移反应产生丰中子超重核素成为可能，将为探索“超重核稳定岛”提供重大机遇。本项目将针对重锕系核间多核子转移反应特点，解决丰中子超重核素分离关键技术，设计建造一台集转靶系统、气体单元、六极离子导向器、射频四极冷却聚束器、质量分析器于一体的丰中子超重核素分离谱仪。建成后，该谱仪能够制备低能、高品质、脉冲离子束流，如果与相关实验测量设备相连接，将在国际上形成独具特色、极具竞争力的超重核素合成、超重核素衰变性质研究、超重元素化学性质研究、超重原子结构研究综合实验平台。

Since 1960s nuclear theories have predicted the existence of the super-heavy island of stability centered at proton number of 114, 120 or 126 and neutron number of 184 or 172. Exploration of the super-heavy island is crucial for understanding of nuclear structure and properties under extremely strong Coulomb fields, and discovery of the maximum nuclear magic numbers. With the construction of next generation high intensity heavy-ion accelerators, renewed interest in multinucleon transfer reactions with actinide beams and targets has been arising due to the potentials for the production of neutron rich not-yet-known super-heavy nuclides. This would bring us a great opportunity to explore the super-heavy island of stability, and therefore it is now pressing for planning such experiments at near future available accelerator facilities. In this project, we first aim at working out the key techniques to separate the neutron rich super-heavy nuclides from the products of low-energy multinucleon transfer reactions using actinide beams and targets, and then building a dedicated spectrometer for separation of neutron rich super-heavy nuclides. This spectrometer is composed of rotating target system, gas cell, sextuple ion guide device, radio-frequency quadruple ion cooler and buncher, and mass analyzer. It can provide low-energy, high quality, and pulsed ions with atomic mass well identified. Coupling with various experimental detection equipments, the spectrometer will be the first and essentially unique platform in the world for synthesis and decay study of super-heavy nuclides, study of chemical properties of super-heavy elements, and study of atomic structure of super-heavy atoms.