Tea Time学术活动系列邀请报告（273）

　　报告题目: Evolution of fission properties in Fermium region

　　报告人：Timur Shneidman（俄罗斯杜布纳联合核子研究所）

　　时间：2026年3月12日（星期四）15:30-16:30

　　地点：理学院1-401

　　报告内容: I would like to present a model of spontaneous fission, which allows one to describe simultaneously a large set of observables, including mass and charge distributions, distributions of the total kinetic energy (TKE), neutron multiplicity, and angular momenta of the fragments. The model assumes that after crossing the fission barrier a fissioning nucleus can be described as a superposition of dinuclear systems (DNS) specified by masses, charges, and deformations of their constituent fragments. Potential energies of DNS are calculated by taking into account the realistic interaction between the fragments and the deformation-dependent shell and pairing corrections to the binding energies of the fragments. Before the decay, DNS evolves in mass/charge asymmetry coordinates and in deformation of the fragments. Depending on the landscape of potential energy, nucleus can undergo fission from various regions, characterized by different masses, charges and deformations of DNS fragments. This phenomenon leads to the multimodality in mass and TKE distributions. Our investigation of fission properties of even-even $^{244-260}$Fm have shown that in addition to the competition between symmetric and asymmetric fission modes, another type of bimodality, associated with coexistence of spherical and deformed mass symmetric fission modes, is manifested in the vicinity of $^{258}$Fm. The model is also applied to the description of recent experimental data on neutron multiplicities in ${^256,260}$Rf and $^{258,260}$Sg nuclei.

　　报告人简介: Timur Shneidman，俄罗斯杜布纳（Dubna）联合核子研究所高级研究员，长期致力于奇特原子核结构研究。1998年毕业于莫斯科工程物理研究所，2003年获物理与数学科学博士学位。2001-2003年在德国吉森大学从事研究工作，2003年就职于俄罗斯杜布纳联合核子研究所。2004、2016、2025年获联合核子研究所理论物理一等奖，2011年获俄罗斯核子研究联合研究所理论物理学青年科学家奖，同年获得德国DAAD青年科学家奖，2013、2015年获中国国际青年科学家奖。参与著作1部，在《Phys. Rev. Lett.》《Nat. Comm.》《Phys. Lett. B》以及《Phys. Rev. C》等国际顶级期刊发表论文80余篇，引用700余次。 2015年、2016年国家自然科学基金委员会（NSFC）与俄罗斯基础研究基金会（RFBR）双边合作交流项目主要参与人。