辐射驱动不对称性对靶球压缩的影响

定量评估了驱动不对称性对靶球压缩的影响。对于不随时间变化不对称性驱动内爆,2维数值模拟结果表明:收缩比越小,驱动不对称性对靶球压缩变形和中子产额的影响越小;如果靶球压缩变形度为2.0,则相应的中子产额较少30%。改变黑腔长度,可得到不同时空性质辐射流,当腔长为1 350μm时,后来的反向不均匀性能消除前期不对称压缩的影响,最后压缩接近球形,内爆中子产额也最高。靶球压缩X光成像数值分析表明,用成像图的半高全宽(FWHM)值来分析燃料压缩变形特性是合理的。该研究结果已成功地用于神光Ⅱ间接驱动内爆物理实验的理论设计和测量数据分析。

Influence of radiation-driven asymmetry on capsule compression

Good radiation-driven symmetry is crucial for forming center hot spot in the indirect-driven inertial fusion. In this paper, our goal is to assess quantitatively the impacts of the radiation-driven asymmetry on the capsule compression. For the time-independent asymmetry, the 2D simulations show that the impact of the radiation-driven asymmetry on the capsule distortion and neutron yield will reduce as the convergence ratio of the capsule decreases. The neutron yield will degrade by 30% when the capsule distortion is about 2.0. In the hohlraums utilized in experiments, the asymmetry varies in space and time with different hohlraum lengths. For the length of 1 350 μm, the subsequent reversal of flux nonuniformity will be adequate to eliminate the effects of the earlier asymmetry, thus the c