In furtherance to improving agreement between calculated and experimental nuclear data, the nuclear reaction code GAMME was used to calculate the multistep compound(MSC) nucleus double differential cross sections(DDCs...In furtherance to improving agreement between calculated and experimental nuclear data, the nuclear reaction code GAMME was used to calculate the multistep compound(MSC) nucleus double differential cross sections(DDCs) for proton-induced neutron emission reactions using the Feshbach-Kerman-Koonin(FKK) formalism. The cross sections were obtained for reactor structural materials involving ^(52)Cr(p, n)^(52)Mn,^(56)Fe(p,n)^(56)Co, and ^(60)Ni(p, n)^(60)Cu reactions at 22.2 MeV incident energy using the zero-range reaction mechanism. Effective residual interaction strength was 28 MeV, and different optical potential parameters were used for the entrance and exit channels of the proton-neutron interactions. The calculated DDCs were fitted to experimental data at the same backward angle of 150°, where the MSC processes dominate. The calculated and experimental data agree well in the region of pre-equilibrium(MSC) reaction dominance against a weaker fit at the lower emission energies. We attribute underestimations to contributions from the other reaction channels and disagreement at higher outgoing energies to reactions to collectively excited states. Contrary to the FKK multi-step direct calculations, contributions from the higher stages to the DDCs are significant. Different sets of parameters resulted in varying levels of agreement of calculated and experimental data for the considered nuclei.展开更多
The structures of the neutron deficient Nd isotopes of A=128～140 are studied in a schematic hamiltonian in the interacting boson model. The level structure and E2 transitions can be well described in the sch...The structures of the neutron deficient Nd isotopes of A=128～140 are studied in a schematic hamiltonian in the interacting boson model. The level structure and E2 transitions can be well described in the scheme. In particular, the backbending in the ground state band is well reproduced.展开更多
Recent years have witnessed intense activity concerning the study of nuclei with equal numbers of neutrons and protons （N = Z）. Exotic properties have been exhibited in the N = Z nuclei, especially in those with ato...Recent years have witnessed intense activity concerning the study of nuclei with equal numbers of neutrons and protons （N = Z）. Exotic properties have been exhibited in the N = Z nuclei, especially in those with atomic masses around 80. In the present paper, the projected shell model（PSM）together with a relativistic Hartree-Bogoliubov （RHB） theory is used to study the nuclear structure near the N = Z line in the mass A ≈ 80 region. For three Zr isotopes 80,82,84Zr, the projected potential energy surfaces and ground state bands are calculated. It is shown that shape coexistence occurs in all of these nuclei. Moreover, we find that the residual neutron-proton interaction strongly affects the ground state band of 80Zr; however, it slightly modifies those of 82Zr and 84Zr.展开更多
文摘In furtherance to improving agreement between calculated and experimental nuclear data, the nuclear reaction code GAMME was used to calculate the multistep compound(MSC) nucleus double differential cross sections(DDCs) for proton-induced neutron emission reactions using the Feshbach-Kerman-Koonin(FKK) formalism. The cross sections were obtained for reactor structural materials involving ^(52)Cr(p, n)^(52)Mn,^(56)Fe(p,n)^(56)Co, and ^(60)Ni(p, n)^(60)Cu reactions at 22.2 MeV incident energy using the zero-range reaction mechanism. Effective residual interaction strength was 28 MeV, and different optical potential parameters were used for the entrance and exit channels of the proton-neutron interactions. The calculated DDCs were fitted to experimental data at the same backward angle of 150°, where the MSC processes dominate. The calculated and experimental data agree well in the region of pre-equilibrium(MSC) reaction dominance against a weaker fit at the lower emission energies. We attribute underestimations to contributions from the other reaction channels and disagreement at higher outgoing energies to reactions to collectively excited states. Contrary to the FKK multi-step direct calculations, contributions from the higher stages to the DDCs are significant. Different sets of parameters resulted in varying levels of agreement of calculated and experimental data for the considered nuclei.
基金Supported by the National Natural Scie-nce Foundation of China and the Nuclear
文摘The structures of the neutron deficient Nd isotopes of A=128～140 are studied in a schematic hamiltonian in the interacting boson model. The level structure and E2 transitions can be well described in the scheme. In particular, the backbending in the ground state band is well reproduced.
基金Supported by National Natural Science Foundation of China (10675170)Major State Basic Research Developing Program(2007CB815003)+1 种基金Natural Science Foundation of Jiangxi Province (0612003, 2007GZW0476)Foundation of the Education Department of Jiangxi Province ([2007]235)
文摘Recent years have witnessed intense activity concerning the study of nuclei with equal numbers of neutrons and protons （N = Z）. Exotic properties have been exhibited in the N = Z nuclei, especially in those with atomic masses around 80. In the present paper, the projected shell model（PSM）together with a relativistic Hartree-Bogoliubov （RHB） theory is used to study the nuclear structure near the N = Z line in the mass A ≈ 80 region. For three Zr isotopes 80,82,84Zr, the projected potential energy surfaces and ground state bands are calculated. It is shown that shape coexistence occurs in all of these nuclei. Moreover, we find that the residual neutron-proton interaction strongly affects the ground state band of 80Zr; however, it slightly modifies those of 82Zr and 84Zr.
