Neutron spectra of Be(d,n) reaction were measured for deuteron energies from 13.5 to 22 MeV by using a stilbene scintillator detector and flight time technique.A special calibration method of neutron detector efficien...Neutron spectra of Be(d,n) reaction were measured for deuteron energies from 13.5 to 22 MeV by using a stilbene scintillator detector and flight time technique.A special calibration method of neutron detector efficiency for higher energy portion was adopted. The spectral neutron yield per unit beam charge on the Be target at 0° was determined. The fluence-averaged mean neutron energies of the neutron spectra are given as a function of the incident energy for several thresholds. The measured neutron spectra have an almost same shape at different incident deuteron energies. High energy portion (En】1.8MeV) and low energy portion (En【2.0MeV)of the neutron spectra were separately measured and they were concerned with each other by normalization. The energy range of whole neutron spectra is 0.7 MeV to 30MeV.展开更多
The thick target neutron yields （TTNYs） of deuteron-induced reaction on AI and Cu isotopes are analyzed by combining the improved nuclear models and particle transport effects. The modified Glauber model is employed...The thick target neutron yields （TTNYs） of deuteron-induced reaction on AI and Cu isotopes are analyzed by combining the improved nuclear models and particle transport effects. The modified Glauber model is employed mainly to produce the peak of double differential cross section for the breakup process, and the exciton model and the Hauser-Feshbach theory are used for the statistical processes. The thin-layer accumulation method is used to calculate the TTNYs considering the neutron attenuation effects in the target. The calculated results are compared with the existing experimental data, and the analysis method can predict the TTNY data well at the deuteron energy of 40 MeV.展开更多
Research on magnetic mirror reactors has had two serious problems since the beginning stage. One is the magnetohydrodynamic instability due to the negative curvature of the magnetic field lines around the center regio...Research on magnetic mirror reactors has had two serious problems since the beginning stage. One is the magnetohydrodynamic instability due to the negative curvature of the magnetic field lines around the center region of a mirror bottle. Another is the loss of charged particles escaping from the loss cone of a magnetic mirror. We have continued to inquire into a means to solve the latter problem. We here propose a new way which will be able to make a magnitude of a loss angle of a magnetic mirror for deuterons virtually zero.展开更多
It is shown that the formation of a Bose-condensate of delocalized deuterons in solid solutions of metals and deuterium leads to the possibility of a d-d-fusion reaction in which one superfluid deuteron and one deuter...It is shown that the formation of a Bose-condensate of delocalized deuterons in solid solutions of metals and deuterium leads to the possibility of a d-d-fusion reaction in which one superfluid deuteron and one deuteron that does not participate in superfluid motion participate.Overcoming the Coulomb barrier is due to the large kinetic energy of macroscopic superfluid motion.It is shown that the intensity of the nuclear reaction depends on the velocity of the superfluid motion and,as a consequence,on the magnitude of the vector B of the external magnetic field.In the London Electrodynamics approximation,a linear dependence of the power released during the nuclear reaction on the magnitude of the vector B of the external magnetic field is obtained.展开更多
The identification of deuterons with momenta in the range of 0.52−0.72 GeV/c is studied with specific ionization energy loss information using a data sample collected by the BESIII detector at center-of-mass energies ...The identification of deuterons with momenta in the range of 0.52−0.72 GeV/c is studied with specific ionization energy loss information using a data sample collected by the BESIII detector at center-of-mass energies between 4.009 and 4.946 GeV.Clean deuteron samples are selected using time of flight information.For all data samples,the deuteron identification efficiencies are higher than 95%,with a maximum difference of%between data and Monte Carlo simulation.This verifies the effectiveness of the deuteron identification method based on specific ionization energy loss and provides valuable information for future studies on processes involving deuterons in the final state at BESIII.展开更多
This study aims to analyze the differential cross sections （DCSs） of elastic scattering and total reaction cross sections （TRCSs） of the loosely-bound deuteron projectile impinging on lp-shell nuclei, such as 9Be,...This study aims to analyze the differential cross sections （DCSs） of elastic scattering and total reaction cross sections （TRCSs） of the loosely-bound deuteron projectile impinging on lp-shell nuclei, such as 9Be, 12C, and 160, at incident energies ranging between 10.6 and 171 MeV using the continuum discretized coupled channel （CDCC） method. By fitting the experimental data for the DCSs and TRCSs, energy-dependent renormalization factors for the real and imaginary parts of the nucleon-nucleus optical-model potentials deduced from the studies proposed by Koning and Delaroche （KD02） and by Watson, Singh, and Segel （WSS）, are obtained. It is found that with the WSS potential, which was obtained specifically for lp-shell nuclei, the CDCC calculations can simultaneously reproduce both the DCSs and the TRCSs. The results show that it is important to choose appropriate optical potentials to describe deuteron-induced reactions.展开更多
In this paper are illustrated the main features of tunneling travelling between two deuterons within a lattice. Considering thescreening effect due to lattice electrons we compare the d-d fusion rate evaluated from di...In this paper are illustrated the main features of tunneling travelling between two deuterons within a lattice. Considering thescreening effect due to lattice electrons we compare the d-d fusion rate evaluated from different authors assuming different screeningefficiency and different d-d potentials. Then, we propose an effective potential which describes very well the attractive contribution dueto Plasmon exchange between two deuterons and by means of it we will compute the d-d fusion rates for different energy values.展开更多
In this paper the main features of tunneling travelling are illustrated between two deuterons within a lattice.Considering the screening effect due to lattice electrons we compared the d-d fusion rate evaluated from d...In this paper the main features of tunneling travelling are illustrated between two deuterons within a lattice.Considering the screening effect due to lattice electrons we compared the d-d fusion rate evaluated from different authors assuming different screening efficiency and different d-d potentials.Then,we proposed an effective potential which describes very well the attractive contribution due to plasmon exchange between two deuterons and by means of it we will compute the d-d fusion rates for different energy values.展开更多
The effect of deuteron breakup in d-nucleus reaction is treated with the continuum discretized coupled channels （CDCC） approach, and the effects on the total reaction cross sections and elastic scattering angular di...The effect of deuteron breakup in d-nucleus reaction is treated with the continuum discretized coupled channels （CDCC） approach, and the effects on the total reaction cross sections and elastic scattering angular distributions are studied by comparing the calculations of CDCC and spherical optical model with our global deuteron optical potential [Phys. Rev. C 73 （2006） 054605] below 200 MeV, for target nuclei ranging from ^12C to ^208Pb. The contributions from the closed channels to the total reaction and breakup cross sections, and angular distributions of elastic scattering are also seriously discussed.展开更多
The deuteron breakup on heavy targets has been investigated in the framework of an improved quantum molecular dynamics model,focusing on the production of neutrons near zero degrees.The experimental differential cross...The deuteron breakup on heavy targets has been investigated in the framework of an improved quantum molecular dynamics model,focusing on the production of neutrons near zero degrees.The experimental differential cross sections of neutron production in the 102 MeV d+C reactions were reproduced by simulations.Based on the consistency between the model prediction and experiment,the feasibility of producing a neutron beam through the breakup of deuteron on a carbon target was demonstrated.Because of the nucleon Fermi motion inside the deuteron,the energy spectrum of the inclusive neutron near 0°in the laboratory exhibits considerable energy broadening in the main peak,whereas the long tail on the low-energy side is suppressed.By coincidentally measuring the accompanying deuteron breakup proton,the energy of the neutron can be tagged with an intrinsic uncertainty of approximately 5%(1σ).The tagging efficiency of the accompanying proton on the forward-emitted neutron can reach 90%,which ensures that the differential cross section in the(d,np)channel remains two orders higher than that in(p,n)after considering the measurement of accompanying protons.This enables the application of a well-defined energy neutron beam in an event-by-event scheme.展开更多
In this paper we model in a new way the nuclei of deuterium and tritium. We consider the nucleons as toroids that rotate at a constant angular velocity around a line perpendicular to their rotation plane and passing t...In this paper we model in a new way the nuclei of deuterium and tritium. We consider the nucleons as toroids that rotate at a constant angular velocity around a line perpendicular to their rotation plane and passing through the center of mass of the nuclei. Based on exact analytical formulas obtained by us for the electrostatic interaction between two spheres with arbitrary radii and charges, we obtain that the known binding energy of the deuteron and triton has an electromagnetic nature. We also obtain through these formulas the force of interaction inside these nuclei. Besides that, within the framework of the classical model we use, we calculate the volumes and mass densities of the nucleons. Throughout all that we use the experimentally obtained results for the radii and masses of the nucleons and nuclei under study. Through our toroid model we confirm the main experimental results obtained for the deuteron and triton not only for the binding energy but also for the magnetic moments, spins and stability.展开更多
The mechanism of deuteron formation in neutron-induced reactions is studied within the framework of the isospin-dependent quantum molecular dynamics model,using the GEMINI code.The influence of the n+p→d reaction cha...The mechanism of deuteron formation in neutron-induced reactions is studied within the framework of the isospin-dependent quantum molecular dynamics model,using the GEMINI code.The influence of the n+p→d reaction channel is investigated by analyzing the deuteron production cross sections in the neutron-induced reactions12C(n,d),16O(n,d),and 28Si(n,d),with incident energies of 20-100 MeV.By including the n+p→d reaction channel when modeling the collision,the deuteron production cross sections increase,optimizing the cross-section results and bringing them closer to the experimental data values.This indicates that the n+p→d reaction channel is an important mechanism for enhancing deuteron production.展开更多
The deuteron transverse charge density ρC(b) is the two-dimensional Fourier transform of its charge form factor in the impact space. We show that different parameterizations of the charge form factors provide differe...The deuteron transverse charge density ρC(b) is the two-dimensional Fourier transform of its charge form factor in the impact space. We show that different parameterizations of the charge form factors provide different ρC(b),in particular at the central value of impact parameter(b = 0), although all the parameterizations can well reproduce the form factors in the region of small Q2. In addition, we also check the explicit contributions from the different coordinate intervals of the deuteron wave function to its root-mean-square radius.展开更多
Using the quark-like model, we have improved the existing deviation between theoretical and experimental values of magnetic dipole moment of deuteron. Based upon Pauli Exclusion Principle, the constituent quarks form ...Using the quark-like model, we have improved the existing deviation between theoretical and experimental values of magnetic dipole moment of deuteron. Based upon Pauli Exclusion Principle, the constituent quarks form a ground state for l = 0. The expectation value of the deuteron magnetic dipole moment operator is determined to be equal to 0.861 597 8μ N in better agreement with the measured value of 0.857 437 6μ N as compared to the shell model calculations.展开更多
By using a simplified Coulomb explosion model, the laser-driven Coulomb explosion processes of three deuterated alkane clusters, i.e., deuterated methane（CD4）N, ethane（C2D6）N and propane（C3D8）N clusters are simu...By using a simplified Coulomb explosion model, the laser-driven Coulomb explosion processes of three deuterated alkane clusters, i.e., deuterated methane（CD4）N, ethane（C2D6）N and propane（C3D8）N clusters are simulated numerically.The overrun phenomenon that the deuterons overtake the carbon ions inside the expanding clusters, as well as the dependence of the energetic deuterons and fusion neutron yield on cluster size, is discussed in detail. Researches show that the average kinetic energy of deuterons and neutron yield generated in the Coulomb explosion of（C2D6）N cluster are higher than those of（CD4）N cluster with the same size, in qualitative agreement with the reported conclusions from the experiments of（C2 H6）N and（CH4）N clusters. It is indicated that（C2D6）N clusters are superior to（CD4）N clusters as a target for the laser-induced nuclear fusion reaction to achieve a higher neutron yield. In addition, by comparing the relevant data of（C3D8）N cluster with those of（C2D6）N cluster with the same size, it is theoretically concluded that（C3D8）N clusters with a larger competitive parameter might be a potential candidate for improving neutron generation. This will provide a theoretical basis for target selection in developing experimental schemes on laser-driven nuclear fusion in the future.展开更多
Deuteron separation energy is not only the basis for validating the nuclear mass models and nucleon-nucleon interaction potential,but also can determine the stability of a nuclide to certain extent.Bayesian neural net...Deuteron separation energy is not only the basis for validating the nuclear mass models and nucleon-nucleon interaction potential,but also can determine the stability of a nuclide to certain extent.Bayesian neural network(BNN)approach,which has strong predictive power and can naturally give theoretical errors of predicted values,had been successfully applied to study the different kinds of separations except the deuteron separation.In this paper,several typical nuclear mass models,such as macroscopic model BW2,macroscopic-microscopic model WS4,and microscopic model HFB-31,are chosen to study the deuteron separation energy combining BNN approach.The root-mean-square deviations of these models are partly reduced.In addition,the inclusion of physical parameters related to the pair and shell effects in the input layer can further improve the theoretical accuracy for the deuteron separation energy.The results show that the theoretical predictions are more reliable as more physical features of BNN approach are included.展开更多
We have inquired into a means to decrease the number of charged particles escaping from a loss cone of a magnetic mirror reactor as many as possible. We previously reported the way of installing a supplemental magneti...We have inquired into a means to decrease the number of charged particles escaping from a loss cone of a magnetic mirror reactor as many as possible. We previously reported the way of installing a supplemental magnetic mirror (which has a cyclotron heating space within) at the exit of a main magnetic bottle. The cyclotron heating space was set to increase a reflection-efficiency of the supplemental mirror. We could not suppress the loss of the escaping deuteron ions sufficiently even with a very long mirror and a very powerful electric field. Then, in this work we propose a new plan of installing another supplemental mirror besides the previous supplemental mirror. A new mirror is set perpendicularly to the center axis of the main bottle. By the addition of the perpendicular mirror, an efficiency of sending back of escaping deuteron ions is considerably theoretically improved. Also in the previous work, since we did not touch how to supply a high-frequency electric field to the cyclotron heating space, here we consider supplying it by an extraordinary-wave with a cyclotron frequency. It is mentioned that propagation of an extraordinary-wave with an electron cyclotron frequency depends on a magnetic field strength and density of escaping electrons.展开更多
The multiple scattering cluster (MSC) method has been employed to perform a theoretical analysis on carbon is near edge X-ray absorption fine structure of the deuteron acetylene (C2 D2) adsorbed on Si(111)7× 7 at...The multiple scattering cluster (MSC) method has been employed to perform a theoretical analysis on carbon is near edge X-ray absorption fine structure of the deuteron acetylene (C2 D2) adsorbed on Si(111)7× 7 at room temperature. From the MSC study. it is confirmed that the (22D2 molecule is bonded to a pair of adjacent Si adatom and Si restatom with C-Si bond length about 0.18nm. The carbon-deuteron bond is bent away front the surface and the CCD bond angle is about 120°. The molecule plane tilt slightly away from the surface normal. Compared with C2D2 in gas phase, the C-C bond and C-D bond are elongated by about 0.03nm and 0.02nm respectively when acetylene was adsorbed on the subtrate. Keyowrds: adsorption of deuteron acetylene on Si(111)7×7. near edge X- ray absorption fine structure. multiple scattering cluster method展开更多
By using a Hamiltonian based on the coupling through flux lines, we have calculated the interaction energy between two fermions via mass less bosons as well as via massive particles. In the case of interaction via mas...By using a Hamiltonian based on the coupling through flux lines, we have calculated the interaction energy between two fermions via mass less bosons as well as via massive particles. In the case of interaction via mass less bosons we obtain an equivalent expression for the Coulomb＇s energy on the form cthc/r, where a is the fine structure constant. In the case of the interaction via massive particles we obtain that the interaction energy contains a term building the potential well. Also, we take into account the spin-spin interaction of the nucleons and we show that this interaction modulates the interaction potential through a cosine factor. The obtained results are in a good agreement with experimental data, for example, of deuteron. We have determined the radial functions for the deuteron.展开更多
文摘Neutron spectra of Be(d,n) reaction were measured for deuteron energies from 13.5 to 22 MeV by using a stilbene scintillator detector and flight time technique.A special calibration method of neutron detector efficiency for higher energy portion was adopted. The spectral neutron yield per unit beam charge on the Be target at 0° was determined. The fluence-averaged mean neutron energies of the neutron spectra are given as a function of the incident energy for several thresholds. The measured neutron spectra have an almost same shape at different incident deuteron energies. High energy portion (En】1.8MeV) and low energy portion (En【2.0MeV)of the neutron spectra were separately measured and they were concerned with each other by normalization. The energy range of whole neutron spectra is 0.7 MeV to 30MeV.
基金Supported by the Project of China Academy of Engineering Physics under Grant No 2013B0103015
文摘The thick target neutron yields （TTNYs） of deuteron-induced reaction on AI and Cu isotopes are analyzed by combining the improved nuclear models and particle transport effects. The modified Glauber model is employed mainly to produce the peak of double differential cross section for the breakup process, and the exciton model and the Hauser-Feshbach theory are used for the statistical processes. The thin-layer accumulation method is used to calculate the TTNYs considering the neutron attenuation effects in the target. The calculated results are compared with the existing experimental data, and the analysis method can predict the TTNY data well at the deuteron energy of 40 MeV.
文摘Research on magnetic mirror reactors has had two serious problems since the beginning stage. One is the magnetohydrodynamic instability due to the negative curvature of the magnetic field lines around the center region of a mirror bottle. Another is the loss of charged particles escaping from the loss cone of a magnetic mirror. We have continued to inquire into a means to solve the latter problem. We here propose a new way which will be able to make a magnitude of a loss angle of a magnetic mirror for deuterons virtually zero.
文摘It is shown that the formation of a Bose-condensate of delocalized deuterons in solid solutions of metals and deuterium leads to the possibility of a d-d-fusion reaction in which one superfluid deuteron and one deuteron that does not participate in superfluid motion participate.Overcoming the Coulomb barrier is due to the large kinetic energy of macroscopic superfluid motion.It is shown that the intensity of the nuclear reaction depends on the velocity of the superfluid motion and,as a consequence,on the magnitude of the vector B of the external magnetic field.In the London Electrodynamics approximation,a linear dependence of the power released during the nuclear reaction on the magnitude of the vector B of the external magnetic field is obtained.
基金Supported by the National Natural Science Foundation of China(11975118,12205141,12375071)。
文摘The identification of deuterons with momenta in the range of 0.52−0.72 GeV/c is studied with specific ionization energy loss information using a data sample collected by the BESIII detector at center-of-mass energies between 4.009 and 4.946 GeV.Clean deuteron samples are selected using time of flight information.For all data samples,the deuteron identification efficiencies are higher than 95%,with a maximum difference of%between data and Monte Carlo simulation.This verifies the effectiveness of the deuteron identification method based on specific ionization energy loss and provides valuable information for future studies on processes involving deuterons in the final state at BESIII.
基金supported by the National Key R&D Program of China(Grant No.2018YFA0404403)the National Natural Science Foundation of China(Grant Nos.11775004,and 11775036)
文摘This study aims to analyze the differential cross sections （DCSs） of elastic scattering and total reaction cross sections （TRCSs） of the loosely-bound deuteron projectile impinging on lp-shell nuclei, such as 9Be, 12C, and 160, at incident energies ranging between 10.6 and 171 MeV using the continuum discretized coupled channel （CDCC） method. By fitting the experimental data for the DCSs and TRCSs, energy-dependent renormalization factors for the real and imaginary parts of the nucleon-nucleus optical-model potentials deduced from the studies proposed by Koning and Delaroche （KD02） and by Watson, Singh, and Segel （WSS）, are obtained. It is found that with the WSS potential, which was obtained specifically for lp-shell nuclei, the CDCC calculations can simultaneously reproduce both the DCSs and the TRCSs. The results show that it is important to choose appropriate optical potentials to describe deuteron-induced reactions.
文摘In this paper are illustrated the main features of tunneling travelling between two deuterons within a lattice. Considering thescreening effect due to lattice electrons we compare the d-d fusion rate evaluated from different authors assuming different screeningefficiency and different d-d potentials. Then, we propose an effective potential which describes very well the attractive contribution dueto Plasmon exchange between two deuterons and by means of it we will compute the d-d fusion rates for different energy values.
文摘In this paper the main features of tunneling travelling are illustrated between two deuterons within a lattice.Considering the screening effect due to lattice electrons we compared the d-d fusion rate evaluated from different authors assuming different screening efficiency and different d-d potentials.Then,we proposed an effective potential which describes very well the attractive contribution due to plasmon exchange between two deuterons and by means of it we will compute the d-d fusion rates for different energy values.
文摘The effect of deuteron breakup in d-nucleus reaction is treated with the continuum discretized coupled channels （CDCC） approach, and the effects on the total reaction cross sections and elastic scattering angular distributions are studied by comparing the calculations of CDCC and spherical optical model with our global deuteron optical potential [Phys. Rev. C 73 （2006） 054605] below 200 MeV, for target nuclei ranging from ^12C to ^208Pb. The contributions from the closed channels to the total reaction and breakup cross sections, and angular distributions of elastic scattering are also seriously discussed.
基金supported by the National Natural Science Foundation of China(Nos.11961141004,11605119,11965004,12047567,and U1867212)the Jiangsu Natural Science Fund Youth Project(No.BK20160304)+1 种基金China Postdoctoral Science Foundation(No.2017M621818)the Ministry of Science and Technology(No.2020YFE0202001).
文摘The deuteron breakup on heavy targets has been investigated in the framework of an improved quantum molecular dynamics model,focusing on the production of neutrons near zero degrees.The experimental differential cross sections of neutron production in the 102 MeV d+C reactions were reproduced by simulations.Based on the consistency between the model prediction and experiment,the feasibility of producing a neutron beam through the breakup of deuteron on a carbon target was demonstrated.Because of the nucleon Fermi motion inside the deuteron,the energy spectrum of the inclusive neutron near 0°in the laboratory exhibits considerable energy broadening in the main peak,whereas the long tail on the low-energy side is suppressed.By coincidentally measuring the accompanying deuteron breakup proton,the energy of the neutron can be tagged with an intrinsic uncertainty of approximately 5%(1σ).The tagging efficiency of the accompanying proton on the forward-emitted neutron can reach 90%,which ensures that the differential cross section in the(d,np)channel remains two orders higher than that in(p,n)after considering the measurement of accompanying protons.This enables the application of a well-defined energy neutron beam in an event-by-event scheme.
文摘In this paper we model in a new way the nuclei of deuterium and tritium. We consider the nucleons as toroids that rotate at a constant angular velocity around a line perpendicular to their rotation plane and passing through the center of mass of the nuclei. Based on exact analytical formulas obtained by us for the electrostatic interaction between two spheres with arbitrary radii and charges, we obtain that the known binding energy of the deuteron and triton has an electromagnetic nature. We also obtain through these formulas the force of interaction inside these nuclei. Besides that, within the framework of the classical model we use, we calculate the volumes and mass densities of the nucleons. Throughout all that we use the experimentally obtained results for the radii and masses of the nucleons and nuclei under study. Through our toroid model we confirm the main experimental results obtained for the deuteron and triton not only for the binding energy but also for the magnetic moments, spins and stability.
基金the National Natural Science Foundation of China(Nos.11875328 and U1832182)the Natural Science Foundation of Guangdong Province+1 种基金China(No.18zxxt65)Fundamental Research Funds for the Central Universities(19lgpy306and 18lgpy87)。
文摘The mechanism of deuteron formation in neutron-induced reactions is studied within the framework of the isospin-dependent quantum molecular dynamics model,using the GEMINI code.The influence of the n+p→d reaction channel is investigated by analyzing the deuteron production cross sections in the neutron-induced reactions12C(n,d),16O(n,d),and 28Si(n,d),with incident energies of 20-100 MeV.By including the n+p→d reaction channel when modeling the collision,the deuteron production cross sections increase,optimizing the cross-section results and bringing them closer to the experimental data values.This indicates that the n+p→d reaction channel is an important mechanism for enhancing deuteron production.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10975146,11035006,11261130,and 11165005
文摘The deuteron transverse charge density ρC(b) is the two-dimensional Fourier transform of its charge form factor in the impact space. We show that different parameterizations of the charge form factors provide different ρC(b),in particular at the central value of impact parameter(b = 0), although all the parameterizations can well reproduce the form factors in the region of small Q2. In addition, we also check the explicit contributions from the different coordinate intervals of the deuteron wave function to its root-mean-square radius.
文摘Using the quark-like model, we have improved the existing deviation between theoretical and experimental values of magnetic dipole moment of deuteron. Based upon Pauli Exclusion Principle, the constituent quarks form a ground state for l = 0. The expectation value of the deuteron magnetic dipole moment operator is determined to be equal to 0.861 597 8μ N in better agreement with the measured value of 0.857 437 6μ N as compared to the shell model calculations.
基金supported by the National Natural Science Foundation of China(Grant No.11005080)
文摘By using a simplified Coulomb explosion model, the laser-driven Coulomb explosion processes of three deuterated alkane clusters, i.e., deuterated methane（CD4）N, ethane（C2D6）N and propane（C3D8）N clusters are simulated numerically.The overrun phenomenon that the deuterons overtake the carbon ions inside the expanding clusters, as well as the dependence of the energetic deuterons and fusion neutron yield on cluster size, is discussed in detail. Researches show that the average kinetic energy of deuterons and neutron yield generated in the Coulomb explosion of（C2D6）N cluster are higher than those of（CD4）N cluster with the same size, in qualitative agreement with the reported conclusions from the experiments of（C2 H6）N and（CH4）N clusters. It is indicated that（C2D6）N clusters are superior to（CD4）N clusters as a target for the laser-induced nuclear fusion reaction to achieve a higher neutron yield. In addition, by comparing the relevant data of（C3D8）N cluster with those of（C2D6）N cluster with the same size, it is theoretically concluded that（C3D8）N clusters with a larger competitive parameter might be a potential candidate for improving neutron generation. This will provide a theoretical basis for target selection in developing experimental schemes on laser-driven nuclear fusion in the future.
基金Supported by National Natural Science Foundation of China (12065003)Central Government Guidance Funds for Local Scientific and Technological Development of China (Guike ZY22096024)+1 种基金Natural Science Foundation of Guangxi (2019GXNSFDA185011)Scientific Research and Technology Development Project of Guilin (20210104-2)。
文摘Deuteron separation energy is not only the basis for validating the nuclear mass models and nucleon-nucleon interaction potential,but also can determine the stability of a nuclide to certain extent.Bayesian neural network(BNN)approach,which has strong predictive power and can naturally give theoretical errors of predicted values,had been successfully applied to study the different kinds of separations except the deuteron separation.In this paper,several typical nuclear mass models,such as macroscopic model BW2,macroscopic-microscopic model WS4,and microscopic model HFB-31,are chosen to study the deuteron separation energy combining BNN approach.The root-mean-square deviations of these models are partly reduced.In addition,the inclusion of physical parameters related to the pair and shell effects in the input layer can further improve the theoretical accuracy for the deuteron separation energy.The results show that the theoretical predictions are more reliable as more physical features of BNN approach are included.
文摘We have inquired into a means to decrease the number of charged particles escaping from a loss cone of a magnetic mirror reactor as many as possible. We previously reported the way of installing a supplemental magnetic mirror (which has a cyclotron heating space within) at the exit of a main magnetic bottle. The cyclotron heating space was set to increase a reflection-efficiency of the supplemental mirror. We could not suppress the loss of the escaping deuteron ions sufficiently even with a very long mirror and a very powerful electric field. Then, in this work we propose a new plan of installing another supplemental mirror besides the previous supplemental mirror. A new mirror is set perpendicularly to the center axis of the main bottle. By the addition of the perpendicular mirror, an efficiency of sending back of escaping deuteron ions is considerably theoretically improved. Also in the previous work, since we did not touch how to supply a high-frequency electric field to the cyclotron heating space, here we consider supplying it by an extraordinary-wave with a cyclotron frequency. It is mentioned that propagation of an extraordinary-wave with an electron cyclotron frequency depends on a magnetic field strength and density of escaping electrons.
基金The authors acknowledge the financial support of the National Natural Science Foun-dation of China (Grant No.19974036)
文摘The multiple scattering cluster (MSC) method has been employed to perform a theoretical analysis on carbon is near edge X-ray absorption fine structure of the deuteron acetylene (C2 D2) adsorbed on Si(111)7× 7 at room temperature. From the MSC study. it is confirmed that the (22D2 molecule is bonded to a pair of adjacent Si adatom and Si restatom with C-Si bond length about 0.18nm. The carbon-deuteron bond is bent away front the surface and the CCD bond angle is about 120°. The molecule plane tilt slightly away from the surface normal. Compared with C2D2 in gas phase, the C-C bond and C-D bond are elongated by about 0.03nm and 0.02nm respectively when acetylene was adsorbed on the subtrate. Keyowrds: adsorption of deuteron acetylene on Si(111)7×7. near edge X- ray absorption fine structure. multiple scattering cluster method
文摘By using a Hamiltonian based on the coupling through flux lines, we have calculated the interaction energy between two fermions via mass less bosons as well as via massive particles. In the case of interaction via mass less bosons we obtain an equivalent expression for the Coulomb＇s energy on the form cthc/r, where a is the fine structure constant. In the case of the interaction via massive particles we obtain that the interaction energy contains a term building the potential well. Also, we take into account the spin-spin interaction of the nucleons and we show that this interaction modulates the interaction potential through a cosine factor. The obtained results are in a good agreement with experimental data, for example, of deuteron. We have determined the radial functions for the deuteron.
