发表机构
Advanced Science Research Center, Japan Atomic Energy Agency; Department of Pure and Applied Physics, Kansai University; Joint Institute for Nuclear Research; University of Bordeaux, CNRS, LP2i Bordeaux, UMR 5797（日本原子力机构先进科学研究中心; 关西大学纯应用物理系; 俄罗斯联合核研究所; 波尔多大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
利用六维朗之万方程计算$^{258}$Md$^*$裂变，识别出两种对称和两种不对称模式，并发现短模式与主导不对称模式涉及$Z=52$、$N=84$形变壳间隙的紧凑碎片。
AI 中文摘要
在激发能范围 $E^*=6$--36 MeV 内，使用六维朗之万方程计算了 $^{258}$Md$^*$ 的裂变。根据断裂时两个碎片的碎片质量和四极形变，计算事件被分类为两个对称和两个不对称裂变模式。对称模式通过其总动能区分为短（高TKE）和超长（低TKE）模式，而不对称模式在质量不对称性上有所不同。随着激发能的增加，短模式的产额减少，而两个不对称模式的组合产额增加，这与 $^{258}$Md$^*$ 的束内瞬发裂变研究中观察到的现象一致。通过对碎片形状和相关单粒子能级的分析，发现短模式和具有较小质量不对称性的主导不对称模式涉及一个紧凑碎片，其特征是 $Z=52$ 和 $N=84$ 处的形变壳间隙，而互补碎片在这两种模式中具有不同的四极形变。
英文摘要
The fission of $^{258}\mathrm{Md}^{*}$ is calculated in the excitation energy range of $E^{*} = 6$--$36$~MeV using a six-dimensional Langevin framework with the Cassini shape parametrization. The calculated events are classified into two symmetric and two asymmetric fission modes based on the fragment mass and the quadrupole deformations of the two fragments at scission. The symmetric modes are the short mode with high total kinetic energy (TKE) and the superlong mode with low TKE, whereas the asymmetric modes differ in mass asymmetry. With increasing excitation energy, the yield of the short mode decreases, whereas the combined yield of the two asymmetric modes increases, as observed in the in-beam prompt-fission study of $^{258}\mathrm{Md}^{*}$. From an analysis of the fragment shapes and associated single-particle levels, the short mode and the dominant asymmetric mode with the smaller mass asymmetry are found to involve a compact fragment characterized by deformed shell gaps at $Z = 52$ and $N = 84$, while the complementary fragment is compact in the short mode and strongly elongated in the asymmetric mode.
Comments6 pages, 5 figures
