Measurements of the total reaction cross section for^(12-16)C,^(14-17)N and^(16-18)O on carbon target at intermediate energies were performed on RIBLL of HIRFL.A larger enhancement ofσR for^(15)C was observed than th...Measurements of the total reaction cross section for^(12-16)C,^(14-17)N and^(16-18)O on carbon target at intermediate energies were performed on RIBLL of HIRFL.A larger enhancement ofσR for^(15)C was observed than that for its neighbors.The analysis of these data indicates possible existence of an anomalous nuclear structure in^(15)C.A new quantity was suggested as the criterion to distinguish anomalous structure nuclei from normal nuclei.展开更多
Fragments produced in the reaction of 60 MeV/n^(18)O on Be have been measured experimentally.The isotopic distribution of fragmentation reaction is well reproduced by a modified statistical abrasion-ablation model It ...Fragments produced in the reaction of 60 MeV/n^(18)O on Be have been measured experimentally.The isotopic distribution of fragmentation reaction is well reproduced by a modified statistical abrasion-ablation model It is predicted that the isotopic distribution shifts toward the neutron rich side for neutron rich projectile,but this isospin effect decreases with the increase of the atomic number difference Z-Z_(A)and disappears at last,where Z and Z_(A)are atomic numbers of the isotopic distribution and the projectile respectively.展开更多
The excitation function and isospin dependencies ofσR have been investigated by using the Boltzmann-Uehling-Uhlenbeck(BUU)model with a square-type density distribution.When the width parameter of the square distribut...The excitation function and isospin dependencies ofσR have been investigated by using the Boltzmann-Uehling-Uhlenbeck(BUU)model with a square-type density distribution.When the width parameter of the square distribution is obtained by fittingσR at relativistic energies,the BUU-model can reproduce the experimental data at intermediate energies better than Glauber model.The systematical underestimation ofσR at intermediate energy by Glauber model was removed out now by BUU calculation framework.It is also found thatσR is sensitive to nuclear equation of state andσin-NN medium.The difference factor d defined in text is sensitive to the nuclear structure such as neutron halo and neutron skin,etc.展开更多
Isospin effects of the critical phenomena were studied via Xe isotopes in the frame of the lattice gas model.All the critical temperatures for four Xe isotopes are close to 5.5 MeV at the same freeze-out density of ab...Isospin effects of the critical phenomena were studied via Xe isotopes in the frame of the lattice gas model.All the critical temperatures for four Xe isotopes are close to 5.5 MeV at the same freeze-out density of about 0.39ρ0.The critical values of power law parameter of mass distribution,mean multiplicity of intermediate mass fragments,information entropy and Campi's second moment show minor dependence on the isospin at the critical point.展开更多
基金Supported by the National Natural Science Foundation of China for Distinguished Young Scholar under Grand No.19625513National Natural Science Foundation of China under Grant No.19675059+1 种基金Shanghai Science,Technology Development Fund under Grant No.96XD14011Major State Basic Research Development Program(G200077400).
文摘Measurements of the total reaction cross section for^(12-16)C,^(14-17)N and^(16-18)O on carbon target at intermediate energies were performed on RIBLL of HIRFL.A larger enhancement ofσR for^(15)C was observed than that for its neighbors.The analysis of these data indicates possible existence of an anomalous nuclear structure in^(15)C.A new quantity was suggested as the criterion to distinguish anomalous structure nuclei from normal nuclei.
基金Supported by the National Natural Science Foundation of China for Distinguished Young Scholar under Grand No.19625513National Natural Science Foundation of China under Grant No.19675059Shanghai Science and Technology Development Fund under Grant No.96XD14011.
文摘Fragments produced in the reaction of 60 MeV/n^(18)O on Be have been measured experimentally.The isotopic distribution of fragmentation reaction is well reproduced by a modified statistical abrasion-ablation model It is predicted that the isotopic distribution shifts toward the neutron rich side for neutron rich projectile,but this isospin effect decreases with the increase of the atomic number difference Z-Z_(A)and disappears at last,where Z and Z_(A)are atomic numbers of the isotopic distribution and the projectile respectively.
基金Supported by the National Natural Science Foundation of China for Distinguished Young Scholar under Grant No.19625513the National Natural Science Foundation of China under Grant No.19675059,the Major State Basic Research Development Program under Contract No.G200077400the Shanghai Science and Technology Development Fund under Grant No.96XD14011.
文摘The excitation function and isospin dependencies ofσR have been investigated by using the Boltzmann-Uehling-Uhlenbeck(BUU)model with a square-type density distribution.When the width parameter of the square distribution is obtained by fittingσR at relativistic energies,the BUU-model can reproduce the experimental data at intermediate energies better than Glauber model.The systematical underestimation ofσR at intermediate energy by Glauber model was removed out now by BUU calculation framework.It is also found thatσR is sensitive to nuclear equation of state andσin-NN medium.The difference factor d defined in text is sensitive to the nuclear structure such as neutron halo and neutron skin,etc.
基金Supported by the National Natural Science Foundation of China for Distinguished Young Scholar under Grant No.19725521)the National Natural Science Foundation of China under Grant No.19705012+2 种基金the Science and Technology Development Foundation of Shanghai under Grant No.97QA14038the Special Project of the Presidential Foundation of Chinese Academy of Sciencesthe Scientific Research Foundations for Returned Overseas Chinese Scholar by the National Human Resource Administration and Education Administration of China。
文摘Isospin effects of the critical phenomena were studied via Xe isotopes in the frame of the lattice gas model.All the critical temperatures for four Xe isotopes are close to 5.5 MeV at the same freeze-out density of about 0.39ρ0.The critical values of power law parameter of mass distribution,mean multiplicity of intermediate mass fragments,information entropy and Campi's second moment show minor dependence on the isospin at the critical point.