分类: 物理学 >> 核物理学 提交时间: 2024-03-09
摘要: The study of nuclide production and its properties in the N=126 neutron-rich region is the frontier and hot topic in nuclear physics and astrophysics research. The upcoming High energy FRagment Separator (HFRS) at the High Intensity heavy-ion Accelerator Facility (HIAF), an in-flight separator at relativistic energies, is characterized by high beam intensity, large ion-optical acceptance, high magnetic rigidity, and high momentum resolution power. It provides an opportunity for the study of the production and properties of neutron-rich nuclei around N=126. In this paper, an experimental scheme is proposed to produce the neutron-rich nuclei around N=126 and simultaneously measure their mass and lifetime based on the HFRS separator, and the feasibility of this scheme is evaluated by the simulations. The results show that under the high resolution optical mode many new neutron-rich nuclei approaching the r-process abundance peak around A=195 can be produced for the first time, and many nuclei with unknown mass and lifetime can be produced with high statistics. Using the time-of-flight corrected by the measured dispersive position and the energy loss information, the cocktails produced from the 208Pb fragmentation can be unambiguously identified. Moreover, the masses of some neutron-rich nuclei in the vicinity of N=126 can be measured with high precision using the time-of-flight magnetic rigidity technique. This indicates that the HIAF-HFRS facility has potential for the production and property research of neutron-rich nuclei around N=126, which is of great significance for expanding chart of nuclides, developing nuclear theories, and understanding the origin of heavy elements in the universe.
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: In order to study the effect of tensor force, we plan to perform a (p,d) reaction with a 4001600 MeV proton beam on the RIBLL2 at Lanzhou. Based on the experimental conditions of RIBLL2, a Monte Carlo method is used to simulate (p,d) reaction process. The distributions of primary beam and scattered deuterons are given on the target and at the F1, F2, F3, and F4 positions. Considering the yield of the deuteron, to separate the produced deuteron from the background particles, the target thickness is optimized. To obtain a clear particle identification spectrum by time of flight (TOF) and energy loss (E), the distance between the two detectors, as well as the energy and timing resolution of detectors are simulated. As a result, the distance between F2 and F4 is fit for that of TOF. After taking into account the particle distribution at F4, both sizes of Multi-Wire Drift Chamber, namely MWDC2 and MWDC3, are selected to be 50 mm50 mm.
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 experimental data of 100A MeV 12C + 12C elastic scattering are checked by using two-body kinematic calculation and 12C+p elastic scattering. It is shown that the measured data are true and reliable. In the paper, the transformation between the excited energy spectra of the 12C+12C system and the ground state energy spectra of the 12C+p system is introduced. The method of subtraction of the hydrogen background in the natural carbon target used in the experiment is elaborately described and the results are discussed. It is indicated that this method of subtraction of hydrogen background is reasonable and can be used in the data analysis. Based on the elastic scattering cross section of the previous experiment of 12C+p at 95.3A MeV, the hydrogen content entered into the reaction is analyzed. The final hydrogen content in the natural carbon target is (2.73 0.12)%.