【摘要】 探索原子核的电荷与质量极限,合成长寿命超重核是当前原子核物理研究的重要前沿问题之一。本文综述了我们近几年在超重原子核结构性质与合成机制方面取得的理论研究进展。在结构性质方面,利用处理对关联的粒子数守恒方法,基于推转壳模型,系统研究了锕系核与超镄核低激发谱,发展了多维形状约束的协变密度泛函理论并用于研究锕系核势能面和裂变位垒以及N=150同中子素中的非轴对称八极关联等。在超重核合成机制方面,系统研究了利用重离子熔合反应合成超重核的三步过程,包括俘获过程——提出了一个位垒穿透概率新公式、熔合过程——提出了一个基于动力学形变势能面的双核模型、存活过程——系统研究了激发态超重复合核存活概率等。系统研究了合成超重核的热熔合反应,得到的熔合蒸发截面与实验符合,并预言了合成119和120号超重元素的生成截面。更多还原

【Abstract】 The exploration of charge and mass limits of atomic nuclei and the synthesis of long-lived or stable superheavy nuclei(SHN) are on the frontier of modern nuclear physics. Recent theoretical progresses made by us on the study of structure and synthesis mechanism of SHN are reviewed. The study of structure properties includes a systematic study of low-lying spectra of actinide and transfermium nuclei by using a cranked shell model with the pairing treated by a particle number conserving method(PNC-CSM), the study of potential energy surfaces and fission barriers of actinide nuclei and non-axial octupole correlations in N = 150 isotones by using newly-developed multi-dimensional constraint covariant density functional theories(MDCCDFT). The study of the synthesis mechanism of SHN is carried out by examining in details of the three steps in producing SHN via heavy-ion fusion reactions: i) For the capture process, a new barrier penetration formula is proposed for potential barriers containing a long-range Coulomb interaction; ii) For the fusion process, a dinuclear system model with a dynamical potential energy surface(the DNS-DynPES model) is developed; and iii) For the survival process, a systematic study of the survival probability against fission in the 1n-channel of SHN with 100 Z 134 is made and it is found that the survival probability in the 1n-channel is mainly determined by the nuclear shell effects. By using the DNS-DynPES model, hot fusion reactions for synthesizing SHN with charge numbers Z = 112 ～ 120 are studied. The calculated evaporation residue cross sections are in good agreement with available data and predictions are made for synthesizing SHN with Z = 119 and 120.更多还原