A method based on the dinuclear system(DNS)is proposed to describe the angular distribution of products in multinucleon transfer(MNT)reactions.By considering fluctuation effects,the angular distributions of reactions ...A method based on the dinuclear system(DNS)is proposed to describe the angular distribution of products in multinucleon transfer(MNT)reactions.By considering fluctuation effects,the angular distributions of reactions involving^(136)Xe+^(208)Pb,^(136)Xe+^(209)Bi,^(86)Kr+^(166)Er,^(84)Kr+^(209)Bi,and^(84)Kr+^(208)Pb are examined,demonstrating good agreement with experimental data.Moreover,the double differential cross-sections(dσ^(2)/dl_(i)dΘand dσ^(2)/dZdΘ)of reactions^(136)Xe+^(208)Pb and^(136)Xe+^(209)Bi are analyzed to explore the mechanism of angular distribution in MNT reactions.Additionally,the optimal angles for detecting N=126 isotopes are determined via an analysis on the influence of proton and neutron numbers of the projectiles on the angular distribution of the N=126 isotopic line.The results of this study can provide valuable insights for experimental detection.展开更多
Within the framework of the dinuclear system model,the multinucleon transfer dynamics for nearly symmetric nuclear collisions has been investigated.The reaction mechanism in the systems of 198Pt+198Pt and 204Hg+198Pt ...Within the framework of the dinuclear system model,the multinucleon transfer dynamics for nearly symmetric nuclear collisions has been investigated.The reaction mechanism in the systems of 198Pt+198Pt and 204Hg+198Pt was investigated at beam energies around the Coulomb barrier.It was found that the isotopic yields are enhanced with increased incident energy in the domain of proton-rich nuclides.However,the production on the neutron-rich side weakly depends on the energy.The angular distribution with the beam energy was also analyzed in the multinucleon transfer reactions.Projectile-like fragments were produced toward the forward emission with increasing incident energy.The target-like fragments manifested the opposite trend in the transfer reactions.展开更多
The 13C（7Li, 6He）laN reaction is measured at E（TLi） = 34 MeV with the Q3D mag- netic spectrometer of HI-13 tandem accelerator. Angular distributions at forward angles for proton transfer to the ground and the firs...The 13C（7Li, 6He）laN reaction is measured at E（TLi） = 34 MeV with the Q3D mag- netic spectrometer of HI-13 tandem accelerator. Angular distributions at forward angles for proton transfer to the ground and the first excited states in 14N are obtained. In addition, angular distri- bution for 7Li ＋ 13C elastic scattering is also measured. The optical potential parameters for the entrance and exit channels of the transfer reactions are derived by fitting the 7Li ＋ 13C and 6Li ＋ 14N elastic scattering experimental data, and their angular distributions are well reproduced by the distorted wave Born approximation calculations. A phase shift of about 2° between the calculations and the experiment data has been found in the earlier （TLi, 6He） study, whereas no such phase shift is observed in the present work.展开更多
The mechanism of multinucleon transfer reactions has been investigated within the dinuclear system model, in which the sequential nucleon transfer is described by solving a set of microscopically derived master equati...The mechanism of multinucleon transfer reactions has been investigated within the dinuclear system model, in which the sequential nucleon transfer is described by solving a set of microscopically derived master equations. The transfer dynamics in the reaction of^(136)Xe+^(208)Pb near Coulomb barrier energies is thoroughly analyzed. It is found that the total kinetic energies of primary fragments are dissipated from the relative motion energy of two touching nuclei and exhibit a symmetric distribution along the fragment mass. The angular distribution of the projectile-like fragments moves forward with increasing beam energy. However, the target-like fragments exhibit an opposite trend. The shell effect is pronounced due to the fragment yields in multinucleon transfer reactions.展开更多
<正>A mathematical method was developed to calculate the yield,energy spectrum and angular distribution of neutrons from D(d,n)~3He(D-D)reaction in a thick deuterium-titanium target for incident deuterons in ene...<正>A mathematical method was developed to calculate the yield,energy spectrum and angular distribution of neutrons from D(d,n)~3He(D-D)reaction in a thick deuterium-titanium target for incident deuterons in energies lower than 1.0MeV.The data of energy spectrum and angular distribution were applied to set up the neutron source model for the beam-shaping-assembly(BSA)design of Boron-Neutron-Capture-Therapy(BNCT)using MCNP-4C code. Three cases of D-D neutron source corresponding to incident deuteron energy of 1000,400 and 150 key were inves- tigated.The neutron beam characteristics were compared with the model of a 2.45 MeV mono-energetic and isotropic neutron source using an example BSA designed for BNCT irradiation.The results show significant differences in the neutron beam characteristics,particularly the fast neutron component and fast neutron dose in air,between the non-isotropic neutron source model and the 2.5 MeV mono-euergetic and isotropic neutron source model.展开更多
Fully differential cross-sections of single ionization of He and Ne atoms are studied by linearly polarized extreme ultraviolet(XUV)photons in the energy range of 22.1 e V–43.7 e V,using a reaction microscope.Photoel...Fully differential cross-sections of single ionization of He and Ne atoms are studied by linearly polarized extreme ultraviolet(XUV)photons in the energy range of 22.1 e V–43.7 e V,using a reaction microscope.Photoelectron angular distributions and theβasymmetry parameters for He 1s^(2) electrons prove the reliability of our experiment,and the β asymmetry parameters extracted from the angular distributions of Ne 2p^(6) electrons are obtained.By comparing with different theoretical calculations,it is found that the contribution of the electron correlation effect in Ne 2p^(6) single ionization becomes increasingly important as the incident photon energy increases,while the relativistic effect is relatively low in the whole incident energy range.Our experimentalβasymmetry parameters may serve as a significant reference to test the most elaborated theories in the field.The datasets presented in this paper,including the photoelectron angular distributions andβasymmetry parameters,are openly available at https://doi.org/10.57760/sciencedb.j00113.00073.展开更多
基金Supported by the Guangdong Major Project of Basic and Applied Basic Research(2021B0301030006)the National Natural Science Foundation of China(12175151,12105181,11847235)the Steady Support Program for Higher Education Institutions of Shenzhen(20200817005440001)。
文摘A method based on the dinuclear system(DNS)is proposed to describe the angular distribution of products in multinucleon transfer(MNT)reactions.By considering fluctuation effects,the angular distributions of reactions involving^(136)Xe+^(208)Pb,^(136)Xe+^(209)Bi,^(86)Kr+^(166)Er,^(84)Kr+^(209)Bi,and^(84)Kr+^(208)Pb are examined,demonstrating good agreement with experimental data.Moreover,the double differential cross-sections(dσ^(2)/dl_(i)dΘand dσ^(2)/dZdΘ)of reactions^(136)Xe+^(208)Pb and^(136)Xe+^(209)Bi are analyzed to explore the mechanism of angular distribution in MNT reactions.Additionally,the optimal angles for detecting N=126 isotopes are determined via an analysis on the influence of proton and neutron numbers of the projectiles on the angular distribution of the N=126 isotopic line.The results of this study can provide valuable insights for experimental detection.
基金supported by the National Natural Science Foundation of China(Nos.11722546 and 11675226)the Talent Program of South China University of Technology。
文摘Within the framework of the dinuclear system model,the multinucleon transfer dynamics for nearly symmetric nuclear collisions has been investigated.The reaction mechanism in the systems of 198Pt+198Pt and 204Hg+198Pt was investigated at beam energies around the Coulomb barrier.It was found that the isotopic yields are enhanced with increased incident energy in the domain of proton-rich nuclides.However,the production on the neutron-rich side weakly depends on the energy.The angular distribution with the beam energy was also analyzed in the multinucleon transfer reactions.Projectile-like fragments were produced toward the forward emission with increasing incident energy.The target-like fragments manifested the opposite trend in the transfer reactions.
基金supported by National Natural Science Foundation of China (Nos. 11021504, 10975193, 10735100, 10720101076)the National Basic Research Program of China (No. 2007CB815003)
文摘The 13C（7Li, 6He）laN reaction is measured at E（TLi） = 34 MeV with the Q3D mag- netic spectrometer of HI-13 tandem accelerator. Angular distributions at forward angles for proton transfer to the ground and the first excited states in 14N are obtained. In addition, angular distri- bution for 7Li ＋ 13C elastic scattering is also measured. The optical potential parameters for the entrance and exit channels of the transfer reactions are derived by fitting the 7Li ＋ 13C and 6Li ＋ 14N elastic scattering experimental data, and their angular distributions are well reproduced by the distorted wave Born approximation calculations. A phase shift of about 2° between the calculations and the experiment data has been found in the earlier （TLi, 6He） study, whereas no such phase shift is observed in the present work.
基金supported by the National Natural Science Foundation of China(Nos.11722546 and 11675226)the Talent Program of South China University of Technology(No.K5180470)
文摘The mechanism of multinucleon transfer reactions has been investigated within the dinuclear system model, in which the sequential nucleon transfer is described by solving a set of microscopically derived master equations. The transfer dynamics in the reaction of^(136)Xe+^(208)Pb near Coulomb barrier energies is thoroughly analyzed. It is found that the total kinetic energies of primary fragments are dissipated from the relative motion energy of two touching nuclei and exhibit a symmetric distribution along the fragment mass. The angular distribution of the projectile-like fragments moves forward with increasing beam energy. However, the target-like fragments exhibit an opposite trend. The shell effect is pronounced due to the fragment yields in multinucleon transfer reactions.
文摘<正>A mathematical method was developed to calculate the yield,energy spectrum and angular distribution of neutrons from D(d,n)~3He(D-D)reaction in a thick deuterium-titanium target for incident deuterons in energies lower than 1.0MeV.The data of energy spectrum and angular distribution were applied to set up the neutron source model for the beam-shaping-assembly(BSA)design of Boron-Neutron-Capture-Therapy(BNCT)using MCNP-4C code. Three cases of D-D neutron source corresponding to incident deuteron energy of 1000,400 and 150 key were inves- tigated.The neutron beam characteristics were compared with the model of a 2.45 MeV mono-energetic and isotropic neutron source using an example BSA designed for BNCT irradiation.The results show significant differences in the neutron beam characteristics,particularly the fast neutron component and fast neutron dose in air,between the non-isotropic neutron source model and the 2.5 MeV mono-euergetic and isotropic neutron source model.
基金the National Natural Science Foundation of China(Grant Nos.11905089 and U1932133)the National Key Research and Development Program of China(Grant No.2017YFA0402300)。
文摘Fully differential cross-sections of single ionization of He and Ne atoms are studied by linearly polarized extreme ultraviolet(XUV)photons in the energy range of 22.1 e V–43.7 e V,using a reaction microscope.Photoelectron angular distributions and theβasymmetry parameters for He 1s^(2) electrons prove the reliability of our experiment,and the β asymmetry parameters extracted from the angular distributions of Ne 2p^(6) electrons are obtained.By comparing with different theoretical calculations,it is found that the contribution of the electron correlation effect in Ne 2p^(6) single ionization becomes increasingly important as the incident photon energy increases,while the relativistic effect is relatively low in the whole incident energy range.Our experimentalβasymmetry parameters may serve as a significant reference to test the most elaborated theories in the field.The datasets presented in this paper,including the photoelectron angular distributions andβasymmetry parameters,are openly available at https://doi.org/10.57760/sciencedb.j00113.00073.
