Author Affiliations
Abstract
1 Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 10088, China
2 Institute of Applied Physics and Computational Mathematics, Beijing 10088, China
Extrapolation of implosion performance between different laser energy scales is investigated for indirect drive through a semi-hydro-equivalent design. Since radiation transport is non-hydro-equivalent, the peak radiation temperature of the hohlraum and the ablation velocity of the capsule ablator are not scale-invariant when the sizes of the hohlraum and the capsule are scale-varied. A semi-hydro-equivalent design method that keeps the implosion velocity Vi, adiabat αF, and (where PL is the laser power and Rhc is the hohlraum and capsule scale length) scale-invariant, is proposed to create hydrodynamically similar implosions. The semi-hydro-equivalent design and the scaled implosion performance are investigated for the 100 kJ Laser Facility (100 kJ-scale) and the National Ignition Facility (NIF-scale) with about 2 MJ laser energy. It is found that the one-dimensional implosion performance is approximately hydro-equivalent when Vi and αF are kept the same. Owing to the non-hydro-equivalent radiation transport, the yield-over-clean without α-particle heating (YOCnoα) is slightly lower at 100 kJ-scale than at NIF-scale for the same scaled radiation asymmetry or the same initial perturbation of the hydrodynamic instability. The overall scaled two-dimensional implosion performance is slightly lower at 100 kJ-scale. The general Lawson criterion factor scales as (where S is the scale-variation factor) for the semi-hydro-equivalent implosion design with a moderate YOCnoα. Our study indicates that χnoα ≈ 0.379 is the minimum requirement for the 100 kJ-scale implosion to demonstrate the ability to achieve marginal ignition at NIF-scale.
Matter and Radiation at Extremes
2024, 9(1): 015601
强激光与粒子束
2020, 32(9): 092004
北京应用物理与计算数学研究所, 北京 100088
激光等离子体相互作用(LPI)是制约在美国国家点火装置(NIF)上实现间接驱动惯性约束聚变的关键问题之一。LPI的激发不仅依赖于激光束功率密度与光束品质, 还强烈依赖于光束所经过的等离子体状态。模拟显示, 内环激光通道上靠近腔壁的He等离子体是受激拉曼散射(SRS)产生的主要区域。通过改变黑腔设计参数(包括构型、尺寸和填充物材料等)可以一定程度优化特定区域的等离子体状态, 进而抑制LPI的产生。据此, 提出了使用大黑腔高激光能量和改变填充气体组分两条控制SRS增长的技术路线。线性分析表明, 两条技术路线效果明显, 可分别将SRS峰值增益降低70%与63%。
间接驱动惯性约束聚变 激光等离子体相互作用 等离子体定标关系 点火黑腔设计 inertial confinement fusion laser and plasma interaction plasma scaling ignition hohlraum design 强激光与粒子束
2015, 27(5): 052001
本文报道用水平滑舟系统液相外延制备n~+InSb/PHg_(1-x)Cd_(?)Te异质结.该异质结外延层厚度在15~25μm之间,由电镜扫描分析出外延层和衬底之间的介面平直,组分过渡很徒.采用该异质结能制备3~5μm(x=0.3)、8~14μm(x=0.2)两波段的红外探测器,从介绍的单元器件的性能来看,该材料是红外焦平面列阵研究方面极有希望的膺选对象.