Numerical Simulation of 2-D Radiation-Drive Ignition Implosion Process

A Lagrangian compatible radiation hydrodynamic algorithm and the nuclear dynamics computing module are developed and implemented in the LARED Integration code, which is a radiation hydrodynamic code based on the 2-D cylindrical coordinates for the numerical simulation of the indirect-drive Inertial Confined Fusion. A number of 1-D and 2-D ignition implosion numerical simulations by using the improved LARED Integration code (ILARED) are presented which show that the 1-D numerical results are consistent with those computed by the 1-D radiation hydrodynamic code RDMG, while the simulation results of the 2-D low-mode radiative asymmetry and hydrodynamic instability growth,according to the physical analysis and anticipation, are satisfactory. The capsules driven by the sources from SGII experiments are also simulated by ILARED, and the fuel shapes agree well with the experimental results. The numerical simulations demonstrate that ILARED can be used in the simulation of the 1-D and 2-D ignition capsule implosion using the multi-group diffusion model for radiation.

Laser-driven plasma collider for nuclear studies

A novel method of initiating nuclear fusion reactions in a full plasma environment was suggested, and a proof-of-concept experiment was carried out with the D ＋D → n＋3He reaction. In this new approach, two plasma jets generated by high-intensity lasers collide headon-head. The center-of-mass energy of the nuclei increases accordingly, and therefore, reaction products can be significantly enhanced, especially in the sub-Coulomb barrier ranges. As a result of the fusion reaction, up to - 7.6 ×105 neutrons had been observed. This new type of ＂plasma collider＂ could provide an innovative tool to study nuclear reactions under astrophysical conditions.

Optimal design of coded aperture used for Z-Pinch driven fusion neutron imaging

Currently,the neutron yield of Z-Pinch is lower than that of laser driven fusion.In the neutron imaging for this facility,the signal to noise ratio(SNR)has a significant influence on the expected spatial resolution of the reconstructed fusion core,especially in the condition of low neutron yield.In this paper,mathematical model is purposed to describe the dependence of aperture parameters on the imaging SNR.The investigation shows that the imaging SNR is closely related to the size of contrast boundary on the point spread function.According to this,a novel non-uniform redundancy penumbra apertures array is designed.In addition,the imaging performances of this novel coded aperture,penumbra aperture and ring aperture are evaluated and compared by Monte Carlo method.The comparison shows that this novel aperture has significant advantage compared to the penumbra aperture which is commonly used for neutron imaging with low yield.The encouraging results can provide reference for the optimal design of the coded aperture used in the neutron imaging for Z-pinch driven fusion with low neutron yield.

Fusion Energy and Stopping Power in a Degenerate DT Pellet Driven by a Laser-Accelerated Proton Beam

In this paper, we have improved the fast ignition scheme in order to have more authority needed for highenergy-gain. Due to the more penetrability and energy deposition of the particle beams in fusion targets, we employ a laser-to-ion converter foil as a scheme for generating energetic ion beams to ignite the fusion fuel. We find the favorable intensity and wavelength of incident laser by evaluating the laser-proton conversion gain. By calculating the source-target distance, proton beam power and energy are estimated. Our analysis is generalized to the plasma degeneracy effects which can increase the fusion gain several orders of magnitude by decreasing the ion-electron collisions in the plasma.It is found that the wavelength of 0.53 μm and the intensity of about 1020W/cm^2, by saving about 10% conversion coefficient, are the suitable measured values for converting a laser into protons. Besides, stopping power and fusion burn calculations have been done in degenerate and non-degenerate plasma mediums. The results indicate that in the presence of degeneracy, the rate of fusion enhances.

基于次临界堆和压水堆的钍铀燃料循环研究

提出了一个实现钍铀燃料循环的新途径,即利用聚变驱动的次临界堆实现钍燃料增殖并将增殖的233U燃料应用于现有压水堆的概念设计。聚变驱动的次临界堆具有丰富的高能中子,因此具有很高的从232Th到233U的燃料增殖率。采用蒙特卡洛程序RMC,对基于国际热核实验堆(ITER)聚变源的次临界堆芯进行了设计分析,结果表明了次临界堆芯具有良好的燃料增殖效果。对于增殖的233U燃料,部分装入国内的压水堆组件及堆芯中,并采用CASMO和SIMULATE程序包进行了分析,结果表明,压水堆中用部分233U燃料替代235U燃料不会对当前的堆芯物理设计产生很大影响,同时可减少锕系废料的产生。