分类: 核科学技术 >> 辐射物理与技术 提交时间: 2024-04-29
摘要: One-neutron stripping process between 6Li and 209Bi was studied at 28, 30, and 34 MeV using the in-beam γ-ray spectroscopy method. The γ-γ coincident analysis clearly identified two γ-rays feeding the ground and long-lived isomeric states, which were employed to determine the cross section. The one-neutron stripping cross sections were similar to the cross sections of complete fusion in the 6Li+209Bi system, but the one-neutron stripping cross sections decreased more gradually at the sub-barrier region. A coupled-reaction-channel calculation was performed to study the detailed reaction mechanism of the one-neutron stripping process in 6Li. The calculations indicated that the first excited state of 5Li is critical in the actual one-neutron transfer mechanism, and the valence proton of 209Bi can be excited to the low-lying excited state in (6Li, 5Li) reaction, unlike in the (d,p) reaction.
分类: 物理学 >> 核物理学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: The temperature of fragmenting source in central heavy-ion collisions at Fermi energy is investigated by the isospin-dependent quantum molecular dynamics model in combination with the statistical decay model GEMINI. Five different nuclear thermometers are used to extract nuclear temperature. We find that the He and Li isotope temperature reaches a plateau at about 70100 MeV/nucleon of beam energy. The slope temperature and the quadrupole fluctuation temperature give high values. The quantum slope temperature and the quantum quadrupole fluctuation temperature are more close to the He and Li isotope temperatures.
分类: 物理学 >> 核物理学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: An improved isospin dependent Boltzmann Langevin model, in which the inelastic channels and momentum dependent interactions are incorporated, is used to investigate the high-density behavior of nuclear symmetry energy. By taking several forms of nuclear symmetry energy, we calculate the time evolutions of neutron over proton ratio, multiplicity and /+ ratio, and the kinetic energy and transverse momentum spectra of /+ ratio in the heavy ion collisions at 400A MeV. It is found that the neutron over proton ratio and /+ ratio are very sensitive to the nuclear symmetry energy, and the is more sensitive to the nuclear symmetry energy than the +. A supersoft symmetry energy results in a larger /+ ratio.