We analyzed quasifission lifetimes of superheavy elements(SHEs)in the atomic number range 104≤Z≤120 and mass number range 243≤A≤301 considering various projectile-target combinations.Nucleusnucleus potentials were...We analyzed quasifission lifetimes of superheavy elements(SHEs)in the atomic number range 104≤Z≤120 and mass number range 243≤A≤301 considering various projectile-target combinations.Nucleusnucleus potentials were evaluated using the nuclear proximity 2010 model,and quasifission barriers were evaluated as the difference between minimum and maximum potentials.The quasifission lifetimes varied from 0.1 zs to 2040 zs,with lifetimes above 1600 zs for_(145)^(249)Rf,_(143)^(248)Db,_(154)^(260)Sg,and_(156)^(263)Hs.The quasifission lifetimes decreased with increasing Z,dropping to 0.1 zs at Z=120.Shorter quasifission lifetimes may contribute to a reduction in production cross-sections from nanobarns to picobarns for elements with Z=104 to Z=118.Furthermore,the impact of angular momentum on quasifission barriers exhibited a decreasing trend as the atomic number increased.The shortest lifetime of 253 zs was observed at Z=120,while longer lifetimes,such as 659 zs for^(64)Ni+^(196)Pt,suggest enhanced stability.The model was validated against data available in literature,generally producing lower values except for34S+186W and^(238)U+^(48)Ca,where significant increases were observed.展开更多
Fragment mass distributions of quasifission induced by 238U on 160, 26Mg, 32S, 35C1, 40Ca and 65Zn targets at several bombarding energies have been calculated with the two-step model. The experimental data are reprodu...Fragment mass distributions of quasifission induced by 238U on 160, 26Mg, 32S, 35C1, 40Ca and 65Zn targets at several bombarding energies have been calculated with the two-step model. The experimental data are reproduced consistently, and the mechanism of the distribution shape is also analyzed by investigating the different incident channels.展开更多
The quasifission dynamics in the reaction ^(48)Ca+^(244)Pu is investigated in the framework of time-dependent Hartree-Fock(TDHF)theory. The calculations are performed in three-dimensional Cartesian coordinate without ...The quasifission dynamics in the reaction ^(48)Ca+^(244)Pu is investigated in the framework of time-dependent Hartree-Fock(TDHF)theory. The calculations are performed in three-dimensional Cartesian coordinate without any symmetry restrictions. The full Skyrme energy functional is incorporated in our TDHF implementation. The quasifission dynamics is quite sensitive to the angular momentum of colliding system. The contact time of quasifission decreases as a function of angular momentum and then forms a plateau with small oscillations. The quasifission process is accompanied by an important multi-nucleon transfer. The quantum shell effect plays a crucial role in the mass and charge of quasifission fragments. The mass-angle distribution of the fragments is calculated, which can be compared directly with future experiments.展开更多
The entrance-channel dynamics including capture, fusion, and quasifission processes for the reaction ^40Ca+^208Pb is investigated in the fully microscopic time-dependent Hartree-Fock(TDHF) theory. The calculations are...The entrance-channel dynamics including capture, fusion, and quasifission processes for the reaction ^40Ca+^208Pb is investigated in the fully microscopic time-dependent Hartree-Fock(TDHF) theory. The calculations are performed in three-dimensional Cartesian coordinate without any symmetry restrictions, in which the full Skyrme energy functional SLy4d and SLy5 are adopted.We study the energy dependence of capture cross sections, and find that the experimental data are well reproduced by the TDHF calculations. Both fusion and quasifission events are observed in the reaction ^40Ca+^208Pb. The contact time, mass and charge of quasifission fragments show a wide distribution in SLy4d compared with SLy5, implying that more nucleons are transferred in the SLy4d calculations. We find that the total kinetic energy of quasifission fragments in the TDHF calculations is distributed around Viola systematics, indicating that most of the relative kinetic energy is dissipated in quasifission dynamics.展开更多
文摘We analyzed quasifission lifetimes of superheavy elements(SHEs)in the atomic number range 104≤Z≤120 and mass number range 243≤A≤301 considering various projectile-target combinations.Nucleusnucleus potentials were evaluated using the nuclear proximity 2010 model,and quasifission barriers were evaluated as the difference between minimum and maximum potentials.The quasifission lifetimes varied from 0.1 zs to 2040 zs,with lifetimes above 1600 zs for_(145)^(249)Rf,_(143)^(248)Db,_(154)^(260)Sg,and_(156)^(263)Hs.The quasifission lifetimes decreased with increasing Z,dropping to 0.1 zs at Z=120.Shorter quasifission lifetimes may contribute to a reduction in production cross-sections from nanobarns to picobarns for elements with Z=104 to Z=118.Furthermore,the impact of angular momentum on quasifission barriers exhibited a decreasing trend as the atomic number increased.The shortest lifetime of 253 zs was observed at Z=120,while longer lifetimes,such as 659 zs for^(64)Ni+^(196)Pt,suggest enhanced stability.The model was validated against data available in literature,generally producing lower values except for34S+186W and^(238)U+^(48)Ca,where significant increases were observed.
基金supported by the National Natural Science Foundation of China(Grant Nos.11275068,11375062,11305059 and 10979024)the C3S2 Computing Center in Huzhou Teachers College
文摘Fragment mass distributions of quasifission induced by 238U on 160, 26Mg, 32S, 35C1, 40Ca and 65Zn targets at several bombarding energies have been calculated with the two-step model. The experimental data are reproduced consistently, and the mechanism of the distribution shape is also analyzed by investigating the different incident channels.
基金supported by the National Natural Science Foundation of China(Grants Nos.11175252,and 11575189)Presidential Fund of University of Chinese Academy of Sciencesthe Natural Science Foundation of China-Japan Society for the Promotion of Science International Cooperation and Exchange Program(Grant No.11711540016)
文摘The quasifission dynamics in the reaction ^(48)Ca+^(244)Pu is investigated in the framework of time-dependent Hartree-Fock(TDHF)theory. The calculations are performed in three-dimensional Cartesian coordinate without any symmetry restrictions. The full Skyrme energy functional is incorporated in our TDHF implementation. The quasifission dynamics is quite sensitive to the angular momentum of colliding system. The contact time of quasifission decreases as a function of angular momentum and then forms a plateau with small oscillations. The quasifission process is accompanied by an important multi-nucleon transfer. The quantum shell effect plays a crucial role in the mass and charge of quasifission fragments. The mass-angle distribution of the fragments is calculated, which can be compared directly with future experiments.
基金supported by the National Natural Science Foundation of China(Grant Nos.11575189,and 11175252)NSFC-JSPS International Cooperation Program(Grant No.11711540016)the Presidential Fund of Universities and Colleges Admissions Service(UCAS)
文摘The entrance-channel dynamics including capture, fusion, and quasifission processes for the reaction ^40Ca+^208Pb is investigated in the fully microscopic time-dependent Hartree-Fock(TDHF) theory. The calculations are performed in three-dimensional Cartesian coordinate without any symmetry restrictions, in which the full Skyrme energy functional SLy4d and SLy5 are adopted.We study the energy dependence of capture cross sections, and find that the experimental data are well reproduced by the TDHF calculations. Both fusion and quasifission events are observed in the reaction ^40Ca+^208Pb. The contact time, mass and charge of quasifission fragments show a wide distribution in SLy4d compared with SLy5, implying that more nucleons are transferred in the SLy4d calculations. We find that the total kinetic energy of quasifission fragments in the TDHF calculations is distributed around Viola systematics, indicating that most of the relative kinetic energy is dissipated in quasifission dynamics.
