2003 Vol. 20, No. 2
Display Method:
2003, 20(2): 71-75.
doi: 10.11804/NuclPhysRev.20.02.071
Abstract:
The status and development of the studies on reaction mechanism for synthesis of superheavy elements has been reviewed. In this paper it is pointed out the difficulties existing in the studies and synthesis of superheavy elements and some conceives for measurement and identification of very heavy residues. The fusion of nearsymmetric reaction systems is discussed and proposed to do more investigations on the fusion cross sections of these reactions on both theory and experiment.
The status and development of the studies on reaction mechanism for synthesis of superheavy elements has been reviewed. In this paper it is pointed out the difficulties existing in the studies and synthesis of superheavy elements and some conceives for measurement and identification of very heavy residues. The fusion of nearsymmetric reaction systems is discussed and proposed to do more investigations on the fusion cross sections of these reactions on both theory and experiment.
2003, 20(2): 76-90.
doi: 10.11804/NuclPhysRev.20.02.076
Abstract:
The history of the synthesis of the transuranium nuclei is briefly introduced. The most successful techniques currently used for synthesizing superheavy nuclei are surveyed and discussed in detail. The drawbacks and the problems for reaching the stability island of superheavy nuclei with the techniques currently used are discussed. The present status and perspectives of the super heavy nuclei research at different laboratories are also introduced. Finally, a brief prospect on the trends...
The history of the synthesis of the transuranium nuclei is briefly introduced. The most successful techniques currently used for synthesizing superheavy nuclei are surveyed and discussed in detail. The drawbacks and the problems for reaching the stability island of superheavy nuclei with the techniques currently used are discussed. The present status and perspectives of the super heavy nuclei research at different laboratories are also introduced. Finally, a brief prospect on the trends...
2003, 20(2): 91-95.
doi: 10.11804/NuclPhysRev.20.02.091
Abstract:
Several important aspects in the cross section calculations for the synthesis of superheavy nuclei have been inquired. They are the effects of the coupledchannels, the damping of shell correction energy, the collective enhancements in the level density and the spin distributions of evaporation residues. The channel coupling of relative motion with internal degrees of freedom will enhance significantly the capture cross section at subbarrier energies. However, recent measurements of spin distributions for ...
Several important aspects in the cross section calculations for the synthesis of superheavy nuclei have been inquired. They are the effects of the coupledchannels, the damping of shell correction energy, the collective enhancements in the level density and the spin distributions of evaporation residues. The channel coupling of relative motion with internal degrees of freedom will enhance significantly the capture cross section at subbarrier energies. However, recent measurements of spin distributions for ...
2003, 20(2): 96-98.
doi: 10.11804/NuclPhysRev.20.02.096
Abstract:
The present status of investigation on the surperheavy nuclei are analyzed. After 259Db synthesized, the next objective nuclide is determined to be265Bh, a new isotope of Z=107 element, according to our existing available equipment and conditions.The test result of the MG rotating wheel collection and detection system is described. The αdecay spectra of motherdaughter of the product252No from24Mg +232Th reaction are observed and measured successfully in this test experiment. It is regarde...
The present status of investigation on the surperheavy nuclei are analyzed. After 259Db synthesized, the next objective nuclide is determined to be265Bh, a new isotope of Z=107 element, according to our existing available equipment and conditions.The test result of the MG rotating wheel collection and detection system is described. The αdecay spectra of motherdaughter of the product252No from24Mg +232Th reaction are observed and measured successfully in this test experiment. It is regarde...
2003, 20(2): 99-101.
doi: 10.11804/NuclPhysRev.20.02.099
Abstract:
A new setup was built in IMP. The reaction 24Mg+232Th was performed as a test experiment for this setup. The decaychains of 252No and 253No have been observecl in this reaction. The results show that this setup is efficient for the rear events and it is possible to use this setup in the future experiment.
A new setup was built in IMP. The reaction 24Mg+232Th was performed as a test experiment for this setup. The decaychains of 252No and 253No have been observecl in this reaction. The results show that this setup is efficient for the rear events and it is possible to use this setup in the future experiment.
2003, 20(2): 102-110.
doi: 10.11804/NuclPhysRev.20.02.102
Abstract:
The progress and challenge on studies of superheavy elements both experiments and theories has been briefly introduced. It is emphasis to introduce a generalized liquid drop model, including the proximity effects, the asymmetry, an accurate nuclear radius, and quasi molecular shapes. The α decay halflives of 373 nuclei and superheavy elements have been calculated in the generalized liquid drop model and compared with the available experimental data. The deformed energies have also been obtained ...
The progress and challenge on studies of superheavy elements both experiments and theories has been briefly introduced. It is emphasis to introduce a generalized liquid drop model, including the proximity effects, the asymmetry, an accurate nuclear radius, and quasi molecular shapes. The α decay halflives of 373 nuclei and superheavy elements have been calculated in the generalized liquid drop model and compared with the available experimental data. The deformed energies have also been obtained ...
2003, 20(2): 111-115.
doi: 10.11804/NuclPhysRev.20.02.111
Abstract:
In the concept of Dinuclear system (DNS) the complete fusion probability of two touch nuclei via nucleon transfer is described by numerically solving the Master equation. The excitation energy of two colliding nuclei is supplied by the energy dissipation of their relative motion, thus the nucleon transfer process and the relative motion are coupled. For Pb based cold fusion reactions to form super heavy nuclei, the optimal excitation energy, the capture crosssection to form a DNS, the compound nuclear ...
In the concept of Dinuclear system (DNS) the complete fusion probability of two touch nuclei via nucleon transfer is described by numerically solving the Master equation. The excitation energy of two colliding nuclei is supplied by the energy dissipation of their relative motion, thus the nucleon transfer process and the relative motion are coupled. For Pb based cold fusion reactions to form super heavy nuclei, the optimal excitation energy, the capture crosssection to form a DNS, the compound nuclear ...
2003, 20(2): 116-120.
doi: 10.11804/NuclPhysRev.20.02.116
Abstract:
The groundstate properties of superheavy nuclei are investigated using the SkyrmeHartreeFock model. The pairing correlation is treated by the BCS method with the pairing δ force. Binding energies, α decays, spontaneous fissions, shell structures and deformations are discussed. Our calculations reproduce experimential binding energies and α decay energies.It is found that superheavy nuclei can be grouped with two kinds of deformations: i) well deformed prolate shapes (β2≈0.2) around 270108...
The groundstate properties of superheavy nuclei are investigated using the SkyrmeHartreeFock model. The pairing correlation is treated by the BCS method with the pairing δ force. Binding energies, α decays, spontaneous fissions, shell structures and deformations are discussed. Our calculations reproduce experimential binding energies and α decay energies.It is found that superheavy nuclei can be grouped with two kinds of deformations: i) well deformed prolate shapes (β2≈0.2) around 270108...
2003, 20(2): 121-131.
doi: 10.11804/NuclPhysRev.20.02.121
Abstract:
An improved Quantum Molecular Dynamics (QMD) model is proposed and the fusion reactions 40, 48Ca+90, 96Zr are studied by using this model. With our improved QMD model, the ground state properties and their time evolution of nuclei from 6Li to 208Pb can be reproduced reasonably well and the excitation functions of fusion cross section for reactions40Ca+96Zr and 40Ca+96Zr at near barrier can be reproduced remarkably well with the same set of parameters...
An improved Quantum Molecular Dynamics (QMD) model is proposed and the fusion reactions 40, 48Ca+90, 96Zr are studied by using this model. With our improved QMD model, the ground state properties and their time evolution of nuclei from 6Li to 208Pb can be reproduced reasonably well and the excitation functions of fusion cross section for reactions40Ca+96Zr and 40Ca+96Zr at near barrier can be reproduced remarkably well with the same set of parameters...
2003, 20(2): 132-136.
doi: 10.11804/NuclPhysRev.20.02.132
Abstract:
Dissipative dynamics of fusion of massive nuclei is studied in terms of the twocenter shape parameterization. Fusion probability is obtained analytically from a Brownian particle passing over a parabolic potential barrier along the elongation coordinate. The neck variable at the initial contact shape is supposed to be a Gaussian distribution. Fusion probabilities of several symmetric or nearly symmetric systems in central collisions are calculatedand compared with experimental data. Effects of neck folding...
Dissipative dynamics of fusion of massive nuclei is studied in terms of the twocenter shape parameterization. Fusion probability is obtained analytically from a Brownian particle passing over a parabolic potential barrier along the elongation coordinate. The neck variable at the initial contact shape is supposed to be a Gaussian distribution. Fusion probabilities of several symmetric or nearly symmetric systems in central collisions are calculatedand compared with experimental data. Effects of neck folding...
2003, 20(2): 137-147.
doi: 10.11804/NuclPhysRev.20.02.137
Abstract:
The studieson structure and reaction for superheavy elements are reviewed. Based on constrained relativistic mean field(CRMF) theory, binding energiesof elements from Z=102 to Z=112, which can be measured experimentally, as a function of deformation arecalculated, and the properties of equilibrium and saddle point of these nuclides are obtained. Using the single particle levels based on CRMF, the shell effects are obtained with Structinsky method. The cross sections of the cold fusion are est...
The studieson structure and reaction for superheavy elements are reviewed. Based on constrained relativistic mean field(CRMF) theory, binding energiesof elements from Z=102 to Z=112, which can be measured experimentally, as a function of deformation arecalculated, and the properties of equilibrium and saddle point of these nuclides are obtained. Using the single particle levels based on CRMF, the shell effects are obtained with Structinsky method. The cross sections of the cold fusion are est...
2003, 20(2): 148-153.
doi: 10.11804/NuclPhysRev.20.02.148
Abstract:
The Potential Energy Surface (PES) for particle exchange in Dinuclear system is studied in detail. It is found that the nuclear deformation effect can change the shape of PES significantly. The dynamical deformation as a function of the reaction time in the reaction process is investigated in a simple model and we found that its variation with time is dramatic. The fusion probabilities P-CN of some reaction channels based on the mechanism of cold fusion are also calculated.
The Potential Energy Surface (PES) for particle exchange in Dinuclear system is studied in detail. It is found that the nuclear deformation effect can change the shape of PES significantly. The dynamical deformation as a function of the reaction time in the reaction process is investigated in a simple model and we found that its variation with time is dramatic. The fusion probabilities P-CN of some reaction channels based on the mechanism of cold fusion are also calculated.
2003, 20(2): 154-159.
doi: 10.11804/NuclPhysRev.20.02.154
Abstract:
The ground state properties of the eveneven nuclei with proton number Z=94-104 have been systematically calculated in the deformed relativistic meanfield (RMF) theory with two sets of force parameters, TMA and NL Z2. Comparing the calculated binding energies and alphadecay energys with the experimental ones, it is found that theoretical results are in good agreement with experimental data. The reliability of the RMF model for eveneven superheavy nuclei has been tested by this comparison...
The ground state properties of the eveneven nuclei with proton number Z=94-104 have been systematically calculated in the deformed relativistic meanfield (RMF) theory with two sets of force parameters, TMA and NL Z2. Comparing the calculated binding energies and alphadecay energys with the experimental ones, it is found that theoretical results are in good agreement with experimental data. The reliability of the RMF model for eveneven superheavy nuclei has been tested by this comparison...
2003, 20(2): 160-164.
doi: 10.11804/NuclPhysRev.20.02.160
Abstract:
Particle transfer driven potentials in Di nuclear System (DNS) in heavy ion collisions based on 208Pb target are calculated. The driven potential controls the particle transfer velocity in the process governed by the diffusion equation, and as a consequence determines the compound nuclear formation probability of DNS. The minimum excitation energy to form a compound nucleus, which is the optimum excitation energy to form the most stable compound nucleus, has been calculated, and the results are basica...
Particle transfer driven potentials in Di nuclear System (DNS) in heavy ion collisions based on 208Pb target are calculated. The driven potential controls the particle transfer velocity in the process governed by the diffusion equation, and as a consequence determines the compound nuclear formation probability of DNS. The minimum excitation energy to form a compound nucleus, which is the optimum excitation energy to form the most stable compound nucleus, has been calculated, and the results are basica...
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