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 experimental method was used to evaluate the primary isotope yields of semi-central collisions in the reaction system 64Zn+112Sn at 40A MeV. The characteristic nature of the hot nuclear matter at the time of the isotope formation was studied. The multiplicities of light particles (LPs) associated with intermediate mass fragments (IMFs) were determined experimentally by using a kinematical focusing technique. The primary isotope distributions, reconstructed by a Monte Carlo method, were compared with those of the AMD-Gemini simulations. ac/T=0.11 and asym/T=3.34 were extracted from the reconstructed primary fragments yield. These are consistent with those of the primary fragments of the AMD simulation.
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 symmetry energy at the time of the production of intermediate mass fragments (IMFs) is studied using experimentally observed IMF multiplicities combined with quantum statistical model calculations (QSM of Hahn and Stcker). The ratios of difference in chemical potentials between neutrons and protons relative to the temperature, (np)/T, and the double ratio temperature, T, were extracted experimentally in the reactions of 64,70Zn, 64Ni+58,64Ni, 112,124Sn, 197Au, 232Th at 40A MeV. The extracted (np)/T scales linearly with NN, where NN is the asymmetry parameter, (NZ)/A, of the emitting source and (np)/T=(11.11.4)NN0.21 was derived. The experimentally extracted (np)/T and the double ratio temperatures are compared with those from the QSM calculations. The temperatures, T, and densities, , extracted from the (np)/T values agreed with those from the double ratio thermometer which used the yield ratios of d, t, h and particles. However the two analyses of the differential chemical potential analysis and the initial temperature analysis end up almost identical relation between T and . T=5.250.75 MeV is evaluated from the (np)/T analysis, but no density determination was possible. From the extracted T value, the symmetry energy coefficient Esym=14.63.5 MeV is determined for the emitting source of T=5.250.75 MeV.