首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
We propose a five-parameter dumbbell model to describe the fusion and fission processes of massive nuclei, where the collective variables are: the distance ρ between the center-of-mass of two fusing nuclei, the neck parameter ν, asymmetry D, two deformation variables β1 and β2 . The present model has macroscopic qualitative expression of polarization and nuclear collision of head to head, sphere to sphere, waist to waist and so on. The conception of the "projectile eating target" based on open mouth and swallow is proposed to describe the nuclear fusion process, and our understanding of the probability of fusion and quasi-fission is in agreement with some previous work. The calculated fission barriers of a lot of compound nuclei are compared with the experimental data.  相似文献   

2.
Two novel nonlinear mode coupling processes for reversed shear Alfvén eigenmode(RSAE) nonlinear saturation are proposed and investigated. In the first process, the RSAE nonlinearly couples to a co-propagating toroidal Alfvén eigenmode(TAE) with the same toroidal and poloidal mode numbers, and generates a geodesic acoustic mode. In the second process, the RSAE couples to a counter-propagating TAE and generates an ion acoustic wave quasi-mode. The condition for the two processes to occur is favored during current ramp. Both the processes contribute to effectively saturate the Alfvénic instabilities, as well as nonlinearly transfer of energy from energetic fusion alpha particles to fuel ions in burning plasmas.  相似文献   

3.
The current-mode-counting method is a new approach to observing transient processes,especially in transient nuclear fusion,based on the non-homogeneous Poisson process(NHPP)model.In this paper,a new measurement process model of the pulsed radiation field produced by transient nuclear fusion is built based on the NHPP.A simulated measurement is performed using the model,and the current signal from the detector is obtained by simulation based on Poisson process thinning.The neutron time spectrum is reconstructed and is in good agreement with the theoretical value,with its maximum error of a characteristic parameter less than 2.3%.Verification experiments were carried out on a CPNG-6 device at the China Institute of Atomic Energy,with a detection system with a nanosecond response time.The experimental charge amplitude spectra are in good agreement with those obtained by the traditional counting mode,and the characteristic parameters of the time spectrum are in good agreement with the theoretical values.This shows that the current-mode-counting method is effective for the observation of transient nuclear fusion processes.  相似文献   

4.
The(3+1)-dimensional Burgers equation, which describes nonlinear waves in turbulence and the interface dynamics,is considered. Two types of semi-rational solutions, namely, the lump–kink solution and the lump–two kinks solution, are constructed from the quadratic function ansatz. Some interesting features of interactions between lumps and other solitons are revealed analytically and shown graphically, such as fusion and fission processes.  相似文献   

5.
介绍了元素合成的总体框架,特别是其中通过原子核聚变释放能量的核燃烧方式和中子俘获过程,并重点说明了原子核的性质作为输入参数对各种天体过程物理图象的影响. Synthesis of stellar elements is outlined, including the nuclear burning processes by which lighter nuclei are combined to form heavier nuclei through fusion with energy releasing and the neutron capture processes. The scenarios of the stellar evolution as functions of improving nuclear properties are illustrated.  相似文献   

6.
The isotope effects of ablation processes in fusion plasma for five combinations of solid isotopic hydrogenic pellets H2, HD,D2,DT,and T2 have been studied for the first time to our knowledge.The results show that the modifications caused by isotope effects for pellet erosion speeds range from 1 for hydrogen pellet down to 0.487 for tritium pellet and are not negligible in ablation rate calculations.These effects can lead to deeper mass deposition and improved core fuelling efficiency.  相似文献   

7.
We perform a complete calculation for the dilepton production from the processes qq→ll Compton-like (qg-+qll, qg→qU, qq→gll, gluon fusion gg→cc, annihilation qq→cc as well as multiple scattering of quarks in a chemically equilibrating quark-gluon plasma system at finite baryon density. It is found that quark-antiquark annihilation, Compton-like, gluon fusion and multiple scattering of quarks give important contribution. Moreover, the increase of the quark phase life-time with increasing initial quark chemical potential makes the dilepton yield as an increasing function of the initial quark chemical potential.  相似文献   

8.
Studies of thermalization processes of energetic charged particles produced in D-He^3 fusion reactions are very important for calculations of their slowing down time, energy fraction transferred to background ions and electrons and fast ion pressure (that means fast ion β). Based on the assumption of binary collision, the total rate of energy loss of the test particle equals to the sum over the rats of energy losses to the electron and all ion species. For these calculations,  相似文献   

9.
Kinetic effects in the inertial confinement fusion ignition process are far from clear. In this work,we study the Richtmyer–Meshkov instability and reshock processes by using a two-fluid discrete Boltzmann method. The work begins by interpreting the experiment conducted by Collins and Jacobs(2002, J. Fluid Mech. 464, 113–136). It shows that the shock wave causes substances in close proximity to the substance interface to deviate more significantly from their thermodynamic equilibrium state. The ...  相似文献   

10.
A vast body of fusion data has been analyzed for different projectiles and target nuclei. It is indicated that the sub-barrier fusion depends on the fusion Q-value. In terms of a recently introduced fusion Q-value rule and an energy scaling reduction procedure, the experimental fusion excitation functions are reduced and compared with each other. It is found that the reduced fusion excitations of selected fusion systems show a similar trend. The fusion data for massive nuclei are in agreement with the Q-value rule. In the fusion process, the Q contribution should be considered. Within this approach, the sub-barrier fusion cross sections of most fusion systems can be predicted without involving any structure effects of colliding nuclei. Instances of disagreement are presented in a few fusion systems. The use of the energy scaling as a criterion of possible experimental data inconsistency is discussed. More precise experimental fusion data need to be measured.  相似文献   

11.
The crucial role of atomic and molecular collision processes in a number of outstanding issues in current magnetic fusion research is discussed. These issues are related to the achievement and control of thermonuclear burn conditions, thermal power and particle exhaust, and the optimization of fusion reactor performance. The status of the present knowledge on the characteristics of collision processes (cross sections, reaction rate coefficients) involved in these fusion research issues is presented. Significant gaps in this knowledge that prevent a full understanding of the background physics of the above mentioned fusion research problems and may affect the ways of their solution are identified. One of the purposes of the present article is to provide a motivation for undertaking the necessary atomic and molecular physics studies for bridging these gaps.  相似文献   

12.
An avalanche-like increase of research activities in the field was caused by the spectacular announcements and publications about the observation of nuclear fusion processes during the infusion of deuterium into metals. Though, the original claims by Fleischmann and Pons concerning the observation of macroscopic amounts of heat so far seem not to be approved in a quantitative manner by other groups, there are indications for the start of a new interesting field of research at the border between nuclear physics and solid state physics – investigations of nuclear fusion processes in condernsed matter. First conclusions drawn here about possible mechanisms of such processes have to be considered neither complete nor final.  相似文献   

13.
LD130是舞毒蛾核多角体病毒(Lymantria dispar multiple nucleopolyhedrovirus, LdMNPV)的膜融合蛋白(F蛋白),其F1亚基N端疏水的保守区为介导膜融合过程的活性肽段,即融合肽区域. 利用核磁共振的方法,确定了该融合肽在酸性条件下类膜环境中的溶液结构. 结果表明融合肽LdF具有典型的α螺旋结构,整个肽段于类膜环境中呈现两亲性,即螺旋沿轴向可分为亲水侧面和亲脂侧面. 该结构有利于对病毒囊膜与细胞膜融合过程的深入理解与研究.  相似文献   

14.
Fusion hindrance and roles of shell effects in superheavy mass region   总被引:1,自引:0,他引:1  
Y. Aritomo   《Nuclear Physics A》2006,780(3-4):222-246
We present the first attempt of systematically investigating the effects of shell correction energy for a dynamical process, which includes fusion, fusion–fission and quasi-fission processes. In the superheavy mass region, for the fusion process, shell correction energy plays a very important role and enhances the fusion probability when the colliding partner has a strong shell structure. By analyzing the trajectory in three-dimensional coordinate space with the Langevin equation, we reveal the mechanism of the enhancement of the fusion probability caused by ‘cold fusion valleys’. The temperature dependence of shell correction energy is considered.  相似文献   

15.
The effect of electric and magnetic plasma microfields on elementary many‐body processes in plasmas is considered. As detected first by Inglis and Teller in 1939, the electric microfield controls several elementary processes in plasmas as transitions, line shifts and line broadening. We concentrate here on the many‐particle processes ionization, recombination, and fusion and study a wide area of plasma parameters. In the first part the state of art of investigations on microfield distributions is reviewed in brief. In the second part, various types of ionization processes are discussed with respect to the influence of electric microfields. It is demonstrated that the processes of tunnel and rescattering ionization by laser fields as well as the process of electron collisional ionization may be strongly influenced by the electric microfields in the plasma. The third part is devoted to processes of microfield action on fusion processes and the effects on three‐body recombination are investigated. It is shown that there are regions of plasma densities and temperatures, where the rate of nuclear fusion is accelerated by the electric microfields. This effect may be relevant for nuclear processes in stars. Further, fusion processes in ion clusters are studied. Finally we study in this section three‐body recombination effects and show that an electric microfield influences the three‐body electron‐ion recombination via the highly excited states. In the fourth part, the distribution of the magnetic microfield is investigated for equilibrium, nonequilibrium, and non‐uniform magnetized plasmas. We show that the field distribution in a neutral point of a non‐relativistic ideal equilibrium plasma is similar to the Holtsmark distribution for the electrical microfield. Relaxation processes in nonequilibrium plasmas may lead to additional microfields. We show that in turbulent plasmas the broadening of radiative electron transitions in atoms and ions, without change of the principle quantum number, may be due to the Zeeman effect and may exceed Doppler and Stark broadening as well. Further it is shown that for optical radiation the effect of depolarization of a linearly polarized laser beams propagating through a magnetized plasma may be rather strong. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

16.
This lecture reviews the main aspects associated with fusion processes between heavy ions at energies below the Coulomb barrier. We discuss in particular the novel features arising in the case of fusion with weakly-bound nuclei. The role of continuum states and the coupling to break-up channels are particularly emphasized.  相似文献   

17.
 对少高能中子的D-3He聚变系统的点火燃烧过程进行了解析研究,给出了D-3He聚变点火和燃烧条件,并用数值模拟方法计算了几个典型的物理模型,得到了有关的物理图象和一些主要计算结果。研究结果进一步论证了D-3He聚变系统是将来少中子聚变电站的最佳候选者。  相似文献   

18.
Quasi-primary fields with dimensions that differ at most byO(1/N) and whose other quantum numbers are all equal, are called degenerate. Multiplets of such fields are produced by a chain of fusion processes. Forcing the fusion to run through different intermediate states leads to matrices of fusion and anomalous dimension amplitudes whose simultaneous diagonalization allows to resolve the degeneracy.  相似文献   

19.
对少高能中子的D-3He聚变系统的点火燃烧过程进行了解析研究,给出了D-3He聚变点火和燃烧条件,并用数值模拟方法计算了几个典型的物理模型,得到了有关的物理图象和一些主要计算结果。研究结果进一步论证了D-3He聚变系统是将来少中子聚变电站的最佳候选者。  相似文献   

20.
徐强  王海晏  杨海燕  王芳  陈鑫 《应用光学》2013,34(2):349-354
针对协同空战中激光数据链路系统传输的友机雷达探测信息与本机红外搜索跟踪系统(IRST)探测信息的不同特性,提出一种基于最优数据压缩的异步信息融合方法来提高探测系统性能。分析了包括时间配准、空间对准、数据融合、目标跟踪的信息融合过程,并通过仿真,对融合前、后所得的观测曲线与目标真实轨迹的比较及其误差曲线进行对比分析,融合后的方位角和俯仰角的误差已经维持在2mrad以内,结果表明该方法可以有效提高数据的精度。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号