The complete-fusion reaction^(204)Pb(^(48)Ca,2n)^(250)No was used to study two activities of^(250)No with distinct half-lives.A total of 1357 events were observed in the SFiNx neutron detection system.The average numb...The complete-fusion reaction^(204)Pb(^(48)Ca,2n)^(250)No was used to study two activities of^(250)No with distinct half-lives.A total of 1357 events were observed in the SFiNx neutron detection system.The average number of neutrons emitted per spontaneous fission of^(250)No was determined to be(4.1±0.1).The unusually symmetrical shape of the prompt neutron multiplicity distribution was restored and presented for the first time.Statistical tests were performed to compare the prompt neutron multiplicity distributions associated with the ground state and K-isomer state decays.展开更多
The angular momentum dependencies parity bands of heavy nuclei have been analyzed of parity splitting and electric dipole transitions in the alternating It is shown that these dependencies can be treated in a universa...The angular momentum dependencies parity bands of heavy nuclei have been analyzed of parity splitting and electric dipole transitions in the alternating It is shown that these dependencies can be treated in a universal manner with a single critical angular momentum parameter, which characterizes phase transition from octupole vibrations to the stable octupole deformation. Using the simple but useful model of axially-symmetric reflection- asymmetric mode, the analytical expressions for parity splitting and electric dipole transitional moment have been obtained. The findings are in good agreement with the experimental data for various isotopes of Ra, Th, U, and Pu.展开更多
A theoretical evaluation of the collective excitation spectra of nucleus at large deformations is possible within the framework of the dinuclear system(DNS) model, which treats the wave function of the fissioning nucl...A theoretical evaluation of the collective excitation spectra of nucleus at large deformations is possible within the framework of the dinuclear system(DNS) model, which treats the wave function of the fissioning nucleus as a superposition of a mononucleus configuration and two-cluster configurations in a dynamical way, permitting exchange of nucleons between clusters. In this work the method of calculation of the potential energy and the collective spectrum of fissioning nucleus at scission point is presented. Combining the DNS model calculations and the statistical model of fission we calculate the angular distribution of fission fragments for the neutron–induced fission of239 Pu.展开更多
文摘The complete-fusion reaction^(204)Pb(^(48)Ca,2n)^(250)No was used to study two activities of^(250)No with distinct half-lives.A total of 1357 events were observed in the SFiNx neutron detection system.The average number of neutrons emitted per spontaneous fission of^(250)No was determined to be(4.1±0.1).The unusually symmetrical shape of the prompt neutron multiplicity distribution was restored and presented for the first time.Statistical tests were performed to compare the prompt neutron multiplicity distributions associated with the ground state and K-isomer state decays.
基金Supported by the RFBR(Moscow)(16-02-00068A)the Russian Government Subsidy Program of the Competitive Growth of Kazan Federal University+5 种基金partly supported by the National Key R&D Program of China(2018YFA0404402)the NSF of China(11525524,11621131001,11647601,11747601,11711540016)the CAS Key Research Program of Frontier Sciences(QYZDB-SSWSYS013)the IAEA CRP“F41033”the HPC Cluster of KLTP/ITP-CASthe Supercomputing Center,CNIC of CAS
文摘The angular momentum dependencies parity bands of heavy nuclei have been analyzed of parity splitting and electric dipole transitions in the alternating It is shown that these dependencies can be treated in a universal manner with a single critical angular momentum parameter, which characterizes phase transition from octupole vibrations to the stable octupole deformation. Using the simple but useful model of axially-symmetric reflection- asymmetric mode, the analytical expressions for parity splitting and electric dipole transitional moment have been obtained. The findings are in good agreement with the experimental data for various isotopes of Ra, Th, U, and Pu.
基金Russian Foundation for Basic Research(12-02-91159)Natural Science Foundation of China(11121403,11120101005,11211120152,11275248.)
文摘A theoretical evaluation of the collective excitation spectra of nucleus at large deformations is possible within the framework of the dinuclear system(DNS) model, which treats the wave function of the fissioning nucleus as a superposition of a mononucleus configuration and two-cluster configurations in a dynamical way, permitting exchange of nucleons between clusters. In this work the method of calculation of the potential energy and the collective spectrum of fissioning nucleus at scission point is presented. Combining the DNS model calculations and the statistical model of fission we calculate the angular distribution of fission fragments for the neutron–induced fission of239 Pu.
