基于Gogny能量密度泛函的最新参数化D1 M $^{*}$，用约束Hartree-Fock-Bogoliubov近似描述了435个超重核的裂变. Gogny-D1 M $^{*}$参数化是对现有的实验数据的基准内和第二势垒高度，激发能的裂变异构体和半衰期在一组选定的钚，Cm，Cf，Fm，没有，Rf，Sg，Hs和F1核。结果也与Gogny-D1 M能量密度泛函得到的结果进行了比较。详细研究了原子序数为100 $\le$ Z $\le$ 126的同位素链的最小能量裂变路径，其中包括来自双中子滴线的高达约4 MeV的非常富中子的扇区。还讨论了单粒子能量、基态变形、配对相关、两核子分离能和势垒高度。除了裂变路径外，受约束的哈特里-福克-博戈留博夫框架还提供了集体质量和零点量子转动能和振动能。这些量是用于评估自发裂变半衰期t $_\mathrm{SF}$的系统性的Wentzel-Kramer-Brillouin形式主义内的构建块。通过对Viola-Seaborg公式进行参数化，计算$α$衰变半衰期t $_\mathrmα$，研究了自发裂变与$α$衰变之间的竞争.通过与已有实验数据和其它理论方法的比较，得出结论：D1 M $^{*}$是描述重核和超重核裂变的一个合理的出发点。
英文摘要：
The constrained Hartree-Fock-Bogoliubov approximation, based on the recent parametrization D1M$^{*}$ of the Gogny energy density functional, is used to describe fission in 435 superheavy nuclei. The Gogny-D1M$^{*}$ parametrization is benchmarked against available experimental data on inner and second barrier heights, excitation energies of the fission isomers and half-lives in a selected set of
Pu, Cm, Cf, Fm, No, Rf, Sg, Hs and Fl nuclei. Results are also compared with those obtained with the Gogny-D1M energy density functional. A detailed study of the minimal energy fission paths is carried out for isotopic chains with atomic numbers 100 $\le$ Z $\le$ 126 including very neutron-rich sectors up to around 4 MeV from the two-neutron driplines. Single-particle energies, ground state deformations, pairing correlations, two-nucleon separation energies and barrier heights are also discussed. In addition to fission paths, the constrained Hartree-Fock-Bogoliubov framework provides collective masses and zero-point quantum rotational and vibrational energies. Those quantities are building blocks within the Wentzel-Kramer-Brillouin formalism employed to evaluate the systematic of the spontaneous fission half-lives t$_\mathrm{SF}$. The competition between spontaneous fission and $α$-decay is studied, through the computation of the $α$-decay half-lives t$_\mathrmα$ using a parametrization of the Viola-Seaborg formula. From the comparison with the available experimental data and the results obtained with other theoretical approaches, it is concluded that D1M$^{*}$ represents a reasonable starting point to describe fission in heavy and superheavy nuclei.
The interplay between quadrupole and octupole degrees of freedom is discussed in a series of neutron-rich actinides and superheavy nuclei with $92 \le$ Z $\le 110$ and $186 \le$ N $\le 202$. In addition to the static Hartree-Fock-Bogoliubov approach, dynamical beyond-mean-field correlations are taken into account via both parity restoration and symmetry-conserving Generator Coordinate Method calculations based on the Gogny-D1M energy density functional. Physical properties such as correlation energies, negative-parity excitation energies as well as reduced transition probabilities $B(E1)$ and …
Alpha decay favoured isotopes of some superheavy nuclei: Spontaneous fission versus alpha decay
自发裂变和α衰变是超重核的主要衰变方式。与自发裂变半衰期相比，具有较小α衰变半衰期的超重核将在裂变中存活，并且可以通过α衰变在实验室中检测到。我们研究了Z = 100-130原子范围内的一些超重元素的α衰变半衰期和自发半衰期。超重核的自发裂变半衰期已经用唯象公式计算，α衰变半衰期用Viola-Seaborg-Sobiczewski公式（Sobiczewski et al. 1989）、Brown（1992）的半经验关系式和Dasgupta-Schubert and Reyes（2007）基于广义液滴模型的公式计算。结果报告于此。
This work investigated the first-chance survival probabilities of highly excited compound superheavy nuclei in the prospect of synthesizing new superheavy elements. The main feature of our modelings is the adoption of microscopic temperature dependent fission barriers in calculations of fission rates. A simple derivation is demonstrated to elucidate the connection between Bohr-Wheeler statistical model and imaginary free energy method, obtaining a new formula for fission rates. The best modeling is chosen with respect to reproducing the experimental fission probability of $^{210}$Po. Systemati…
The evolution of structure property along the fission path in the superheavy nucleus $^{256}$Sg is predicted through the multi-dimensional potential-energy(or Routhian)-surface calculations,in which the phenomenological deformed Woods-Saxon potential is adopted. Calculated nuclear deformations and fission barriers for $^{256}_{106}$Sg$_{150}$ and its neighbors, e.g., $^{258,260}$Sg, $^{254}$Rf and $^{252}$No are presented and compared with other theoretical results. A series of energy maps and curves are provided and used to evaluate the corresponding shape-instability properties, especially i…
Simulation of fusion and quasi-fission in nuclear reactions leading to production of superheavy elements using the Constrained Molecular Dynamics model
Superheavy nuclei in microscopic collective Hamiltonian approach: the impact of beyond mean field correlations on the ground state and fission properties
Least action description of dynamic pairing correlations in the fission of Curium and Californium isotopes based on the Gogny energy density functional
Potential energy surfaces and fission barriers of superheavy nuclei are analyzed in the macroscopic-microscopic model. The Lublin-Strasbourg Drop (LSD) is used to obtain the macroscopic part of the energy, whereas the shell and pairing energy corrections are evaluated using the Yukawa-folded potential. A standard flooding technique has been used to determine the barrier heights. It was shown the Fourier shape parametrization containing only three deformation parameters reproduces well the nuclear shapes of nuclei on their way to fission. In addition, the non-axial degree of freedom is taken in…
The systematic investigation of the ground state and fission properties of even-even actinides and superheavy nuclei with $Z=90-120$ from the two-proton up to two-neutron drip lines with proper assessment of systematic theoretical uncertainties has been performed for the first time in the framework of covariant density functional theory (CDFT). These results provide a necessary theoretical input for the r-process modeling in heavy nuclei and, in particular, for the study of fission recycling. Four state-of-the-art globally tested covariant energy density functionals (CEDFs), namely, DD-PC1, DD…
采用基于变形Woods-Saxon单粒子势和Yukawa加指数宏观能的微观-宏观模型，计算了1305个重核和超重核$98\leq Z \leq 126$的静态裂变势垒$B_{f}$，包括偶-偶、奇-偶、偶-奇和奇-奇系统。对于奇核和奇-奇核，在费米能级以下10阶到费米能级以上10阶的能级上，通过极小化一个被阻挡中子或/和质子的组态，计算了绝热势能面.模型的参数，以前已经固定的偶偶重核质量的拟合保持不变。鞍点的搜索已被执行的“假想水流”的方法上的基本五维变形网格，包括三轴。两个辅助网格用于检查质量不对称性和十六极非轴性的影响。基态是通过能量最小化的方法得到的。我们发现非轴性显著地改变了许多核的第一和第二裂变势垒。质量不对称的效应，已知降低了锕系元素中第二个非常变形的势垒，在最重的核中出现在100多个核中变形较小的鞍区。它发生在那些三轴性不起任何作用的马鞍上，这表明质量不对称性和三轴性的影响之间是解耦的。我们还研究了对相互作用强度对$B_f$的交错奇数和偶数粒子数的影响。最后，我们提供了一个比较我们的结果与其他理论裂变势垒的评估和可用的实验估计。
This dissertation deals with theoretical descriptions of nuclear fission and synthesis of superheavy elements via fusion. The associated shape evolutions are treated using a random-walk approach where both the potential energy and the nuclear level density influence the dynamics. The work in this thesis extends the random-walk model by, in addition to the previous description of fragment mass yields, also simulating how much kinetic energy the fission-fragments obtain and the number of neutrons they emit, as well as how these two quantities are correlated. The thesis also presents studies of h…
Constraining the equation of state of nuclear matter from competition of fusion and quasi-fission in the reactions leading to production of the superheavy elements
