Protons are emitted much more affluently in neutron-deficient system ^(40)Ar+^(112)Sn while triton emissions are greater in a neutron-rich system ^(40)Ar+^(124)Sn at incident energy of 30 MeV/u.Similar to neutron,prot...Protons are emitted much more affluently in neutron-deficient system ^(40)Ar+^(112)Sn while triton emissions are greater in a neutron-rich system ^(40)Ar+^(124)Sn at incident energy of 30 MeV/u.Similar to neutron,proton emission provied a dominant contribution to neutralize the system N/Z in the decay process of the hot nuclei.The emission of hydrogen isotopes with high energies is much enhanced in the ^(112)Sn system.The original temperature of the hot nuclei in the ^(40)Ar+^(112)Sn reaction is 5.8±0.3 MeV,about 0.7 MeV higher than 5.1±0.3 MeV as in the ^(40)Ar+^(124)Sn reaction.展开更多
Total reaction cross sections σR for some proton-rich isotones (N = 10) near ^(23)Al on a carbon target have been measured at intermediate energies in the experiment performed at the Radioactive Ion Beam Line of the ...Total reaction cross sections σR for some proton-rich isotones (N = 10) near ^(23)Al on a carbon target have been measured at intermediate energies in the experiment performed at the Radioactive Ion Beam Line of the Heavy Ion Research Facility in Lanzhou. The Z-dependence of σR shows a remarkable enhancement for ^(23)Al relative to its neighbours. The difference factor d has been deduced from the measured σR by using the Glauber or Boltzmann-Uehling-Uhlenbeck models. From the above analysis, a possible one-proton halo structure is suggested for ^(23)Al.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
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 experimental measurement of the total interaction cross sections of N,C,B,and Be isotopes on 12C target at medium energies is described.A new formula that gives a good description of the energy-range relationship ...The experimental measurement of the total interaction cross sections of N,C,B,and Be isotopes on 12C target at medium energies is described.A new formula that gives a good description of the energy-range relationship of energetic ions over a wide energy range is presented.The energy calibration of detectors is made by a Monte Carlo simulation method based on this new formula.展开更多
The angular distributions of intermediate mass fragments with charge numbers from 3 to 24 emitted in 30 MeV/u 40Ar+58,64Ni and 115In reactions over an angular range of 5o-140ohave been measured.In different angular re...The angular distributions of intermediate mass fragments with charge numbers from 3 to 24 emitted in 30 MeV/u 40Ar+58,64Ni and 115In reactions over an angular range of 5o-140ohave been measured.In different angular region an exponential distribution function dσ/dΩ=N exp(-θ/α)was used to fit the measured angular distributions.The decay factor a which can be connected with the interaction time T and the factor N which is related to the intensity of the emission sources have been extracted.The relationship ofα(Z)and N(Z)with Z for different reaction systems and different angular regions has been discussed.The different behavior of dσ/dΩ,α(Z),and N(Z)for the three studied reaction systems exists mainly in the middle and backward angular regions.The dependencies of angular distributions on isospin and the size of reaction systems have also been discussed.展开更多
An inclusive measurement was performed for 30 MeV/u ^(40)Ar+^(58,64)Ni and ^(115)In.By employing the degree of freedom of N/Z,the production mechanism of the high energy component of the intermediate mass fragments(IM...An inclusive measurement was performed for 30 MeV/u ^(40)Ar+^(58,64)Ni and ^(115)In.By employing the degree of freedom of N/Z,the production mechanism of the high energy component of the intermediate mass fragments(IMFs:3≤Z≤13)has been discussed.Special attention has been paid to the target dependence of N/Z ratio of the energetic fragments.These IMFs may be produced by a projectile fragmentation process with energy dissipation.展开更多
The ratio of isotope yields integrated over a part of their energy spectrum is proposed to extract nuclear temperature of the excited emitter nucleus formed in heavy ion reactions.The nuclear temperature extracted fro...The ratio of isotope yields integrated over a part of their energy spectrum is proposed to extract nuclear temperature of the excited emitter nucleus formed in heavy ion reactions.The nuclear temperature extracted from the isotope ratio is consistent with that extracted from the relative populations of the particle unstable states.展开更多
Excitation functions of the dissipative products in the reaction 19F+51V have been measured from 102.25 to 109.50MeV by 250keV steps at θl = 21.7°, 36.1°and 40.5°. The rotation angular velocities ω an...Excitation functions of the dissipative products in the reaction 19F+51V have been measured from 102.25 to 109.50MeV by 250keV steps at θl = 21.7°, 36.1°and 40.5°. The rotation angular velocities ω and the energy coherence widths of the corresponding dinuclear systems were extracted. The coherence rotation and its importance in the reaction process have been discussed.展开更多
Two low-lying isomeric states in 169Ta have been identified via ^(159)Tb(l6O,6nγ)^(169)Ta reaction.Their half-lives are measured to be 28±5ns for the 9/2^(-)level and 17±4 ns for the 5/2^(-)level by using t...Two low-lying isomeric states in 169Ta have been identified via ^(159)Tb(l6O,6nγ)^(169)Ta reaction.Their half-lives are measured to be 28±5ns for the 9/2^(-)level and 17±4 ns for the 5/2^(-)level by using the delayedγ-γcoincidence method.These two isomeric states are considered to be the bandheads with 9/2-[514]and 1/2-[541]configurations,respectively.Possible neutron quasiparticle configuration for the ground state of ^(169)W is discussed.展开更多
High spin states of the odd-odd ^(162)Lu nucleus have been studied via ^(147)Sm(^(19)F,4nγ)reaction at 95MeV beam energy.Level scheme for yrast band based on π[h_(11/2)]v[i_(13/2)]quasiparticle configuration was est...High spin states of the odd-odd ^(162)Lu nucleus have been studied via ^(147)Sm(^(19)F,4nγ)reaction at 95MeV beam energy.Level scheme for yrast band based on π[h_(11/2)]v[i_(13/2)]quasiparticle configuration was established up to I^(π)-(23^(-))for the first time.This band shows the signature inversion in energy before backbending generally appeared in this mass region.It is stressed that the signature splitting in 162Lu is larger than that in 160 Tm nucleus.展开更多
High spin states in ^(170)Ta have been studied via ^(159)Tb(^(16)O,5nγ)^(170)Ta reaction at 105MeV beam energy.Three rotational bands have been observed among which one coupled band and an unfavoredΔI=2 transition s...High spin states in ^(170)Ta have been studied via ^(159)Tb(^(16)O,5nγ)^(170)Ta reaction at 105MeV beam energy.Three rotational bands have been observed among which one coupled band and an unfavoredΔI=2 transition sequence of the semidecoupled band are identified in this work.The effects of theπ1/2^(-)[541]proton intruder orbital are qualitatively discussed.展开更多
基金Supported by the One Hundred Talents Project and Major Subjects of the Chinese Academy of Sciences under Grant No.KJ95T-03。
文摘Protons are emitted much more affluently in neutron-deficient system ^(40)Ar+^(112)Sn while triton emissions are greater in a neutron-rich system ^(40)Ar+^(124)Sn at incident energy of 30 MeV/u.Similar to neutron,proton emission provied a dominant contribution to neutralize the system N/Z in the decay process of the hot nuclei.The emission of hydrogen isotopes with high energies is much enhanced in the ^(112)Sn system.The original temperature of the hot nuclei in the ^(40)Ar+^(112)Sn reaction is 5.8±0.3 MeV,about 0.7 MeV higher than 5.1±0.3 MeV as in the ^(40)Ar+^(124)Sn reaction.
基金Supported by the Major State Basic Research Development Program under contract No.G200077400。
文摘Total reaction cross sections σR for some proton-rich isotones (N = 10) near ^(23)Al on a carbon target have been measured at intermediate energies in the experiment performed at the Radioactive Ion Beam Line of the Heavy Ion Research Facility in Lanzhou. The Z-dependence of σR shows a remarkable enhancement for ^(23)Al relative to its neighbours. The difference factor d has been deduced from the measured σR by using the Glauber or Boltzmann-Uehling-Uhlenbeck models. From the above analysis, a possible one-proton halo structure is suggested for ^(23)Al.
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 Science Foundation of China for Distinguished Young Scholar under Grand No.19625513.
文摘The experimental measurement of the total interaction cross sections of N,C,B,and Be isotopes on 12C target at medium energies is described.A new formula that gives a good description of the energy-range relationship of energetic ions over a wide energy range is presented.The energy calibration of detectors is made by a Monte Carlo simulation method based on this new formula.
基金Supported by the National Natural Science Foundation of China under Grant No.19235012the Foundation of Chinese Academy of Sciences。
文摘The angular distributions of intermediate mass fragments with charge numbers from 3 to 24 emitted in 30 MeV/u 40Ar+58,64Ni and 115In reactions over an angular range of 5o-140ohave been measured.In different angular region an exponential distribution function dσ/dΩ=N exp(-θ/α)was used to fit the measured angular distributions.The decay factor a which can be connected with the interaction time T and the factor N which is related to the intensity of the emission sources have been extracted.The relationship ofα(Z)and N(Z)with Z for different reaction systems and different angular regions has been discussed.The different behavior of dσ/dΩ,α(Z),and N(Z)for the three studied reaction systems exists mainly in the middle and backward angular regions.The dependencies of angular distributions on isospin and the size of reaction systems have also been discussed.
基金Supported by the National Natural Science Foundation of China under Grant No.19205006.
文摘An inclusive measurement was performed for 30 MeV/u ^(40)Ar+^(58,64)Ni and ^(115)In.By employing the degree of freedom of N/Z,the production mechanism of the high energy component of the intermediate mass fragments(IMFs:3≤Z≤13)has been discussed.Special attention has been paid to the target dependence of N/Z ratio of the energetic fragments.These IMFs may be produced by a projectile fragmentation process with energy dissipation.
基金Supported by the National Natural Science Foundation of China.
文摘The ratio of isotope yields integrated over a part of their energy spectrum is proposed to extract nuclear temperature of the excited emitter nucleus formed in heavy ion reactions.The nuclear temperature extracted from the isotope ratio is consistent with that extracted from the relative populations of the particle unstable states.
基金the National Natural Science Foundation of Chinathe Natural Science Foundation of Gansu Province,China.
文摘Excitation functions of the dissipative products in the reaction 19F+51V have been measured from 102.25 to 109.50MeV by 250keV steps at θl = 21.7°, 36.1°and 40.5°. The rotation angular velocities ω and the energy coherence widths of the corresponding dinuclear systems were extracted. The coherence rotation and its importance in the reaction process have been discussed.
基金Supported by the State Education Committee of Chinathe National Natural Science Foundation of China under Grant No.19605008.
文摘Two low-lying isomeric states in 169Ta have been identified via ^(159)Tb(l6O,6nγ)^(169)Ta reaction.Their half-lives are measured to be 28±5ns for the 9/2^(-)level and 17±4 ns for the 5/2^(-)level by using the delayedγ-γcoincidence method.These two isomeric states are considered to be the bandheads with 9/2-[514]and 1/2-[541]configurations,respectively.Possible neutron quasiparticle configuration for the ground state of ^(169)W is discussed.
基金Supported by the Research Fund of National Post-Doctor Committeethe China National Education Committeethe Chinese Academy of Sciences.
文摘High spin states of the odd-odd ^(162)Lu nucleus have been studied via ^(147)Sm(^(19)F,4nγ)reaction at 95MeV beam energy.Level scheme for yrast band based on π[h_(11/2)]v[i_(13/2)]quasiparticle configuration was established up to I^(π)-(23^(-))for the first time.This band shows the signature inversion in energy before backbending generally appeared in this mass region.It is stressed that the signature splitting in 162Lu is larger than that in 160 Tm nucleus.
基金Supported by the State Education Commit tee of Chinathe National Natural Science Foundation of China under Grant No 19605008。
文摘High spin states in ^(170)Ta have been studied via ^(159)Tb(^(16)O,5nγ)^(170)Ta reaction at 105MeV beam energy.Three rotational bands have been observed among which one coupled band and an unfavoredΔI=2 transition sequence of the semidecoupled band are identified in this work.The effects of theπ1/2^(-)[541]proton intruder orbital are qualitatively discussed.
