Fragments produced in the reactions of 69 MeV/nucleon ^(36)Ar and ^(55)MeV/nucleon ^(40)Ar on a Be target have been measured experimentally.The isotopic distributions from fragmentation reaction for both projectiles a...Fragments produced in the reactions of 69 MeV/nucleon ^(36)Ar and ^(55)MeV/nucleon ^(40)Ar on a Be target have been measured experimentally.The isotopic distributions from fragmentation reaction for both projectiles are reproduced by using a modified statistical abrasion-ablation model.Strong isospin effect exhibits in the isotopic distributions produced in ^(36)Ar and ^(40)Ar fragmentation.Experimental evidence is seen for the disappearance of the isospin effect in fragmentation reaction.展开更多
The excitation functions were measured in the reaction of 27Al+27Al at incident energies from 114MeV to 127MeV in steps of 200keV. The detection angles were continuously covered from 10o to 57° in the laboratory ...The excitation functions were measured in the reaction of 27Al+27Al at incident energies from 114MeV to 127MeV in steps of 200keV. The detection angles were continuously covered from 10o to 57° in the laboratory system. The energy autocorrelation functions of the dissipative fragments were analyzed by using different approaches. The nonself-averaging oscillations in the excitation functions were considered due to the angular momentum coherence and damping of the coherent nuclear rotation. The damping results from a quantum chaotic motion.展开更多
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
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
The excitation functions of dissipative products have been measured in the reaction 27Al+27Al at incident energies from 114 to 127MeV in steps of 200keV. Detection angles vary continuously from 10.4° to 57.4°...The excitation functions of dissipative products have been measured in the reaction 27Al+27Al at incident energies from 114 to 127MeV in steps of 200keV. Detection angles vary continuously from 10.4° to 57.4° in laboratory system. An angular coherent width more than 40° in center of mass is obtained. The results from the analysis of excitation functions with nonself-averaging are characterized by a quasi-periodic long-range energy structure embedded in the disorder Ericson fluctuation.展开更多
基金Supported by the Major State Basic Research Development Program in China Under Contract No.G200077400.
文摘Fragments produced in the reactions of 69 MeV/nucleon ^(36)Ar and ^(55)MeV/nucleon ^(40)Ar on a Be target have been measured experimentally.The isotopic distributions from fragmentation reaction for both projectiles are reproduced by using a modified statistical abrasion-ablation model.Strong isospin effect exhibits in the isotopic distributions produced in ^(36)Ar and ^(40)Ar fragmentation.Experimental evidence is seen for the disappearance of the isospin effect in fragmentation reaction.
基金the National Natural Science Foundation (No.19775057), and by the Chinese Academyof Sciences and the Laboratori Nazionale del
文摘The excitation functions were measured in the reaction of 27Al+27Al at incident energies from 114MeV to 127MeV in steps of 200keV. The detection angles were continuously covered from 10o to 57° in the laboratory system. The energy autocorrelation functions of the dissipative fragments were analyzed by using different approaches. The nonself-averaging oscillations in the excitation functions were considered due to the angular momentum coherence and damping of the coherent nuclear rotation. The damping results from a quantum chaotic motion.
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 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the National Natural Science Foundation of China under Grant No.19775057the Chinese Academy of Sciences(No.KJ95T-03).
文摘The excitation functions of dissipative products have been measured in the reaction 27Al+27Al at incident energies from 114 to 127MeV in steps of 200keV. Detection angles vary continuously from 10.4° to 57.4° in laboratory system. An angular coherent width more than 40° in center of mass is obtained. The results from the analysis of excitation functions with nonself-averaging are characterized by a quasi-periodic long-range energy structure embedded in the disorder Ericson fluctuation.
