氘氘冰层贯穿性缺陷对ICF冷冻靶内爆性能的影响

使用二维多群辐射扩散流体力学程序LARED-S, 模拟研究DD冰贯穿性缺陷在方波驱动DD冷冻靶内爆过程中的演化行为及其对内爆性能的影响。模拟结果表明: DD冰层贯穿性缺陷显著降低DD冷冻靶内爆的中子产额, 二维模拟产额仅为一维结果的23.8%。DD冰层贯穿性缺陷使靶丸CH(Si)的烧蚀层生成大幅度的尖钉, 穿透到芯部热斑区。在中子bang-time时刻, 热斑区混入了487 ng的烧蚀物质, 使芯部韧致辐射漏失功率相对一维理想内爆显著升高, 离子温度与DD核反应速度相应降低。同时, 高密度的烧蚀层尖钉把DD热斑推离球心, 显示明显的P1不对称性, 而且高温热斑具有定向流动速度, 降低了内爆动能转化为热斑内能的效率。

Influence of Penetrating Defect in DD Ice Layer on ICF Cryogenic Capsule Implosion Performance

A two-dimensional radiation diffusion hydrodynamic code LARED-S is used to investigate evolution behavior of a penetrating defect and its influences on square-pulsed DD cryogenic capsule implosion performance. It shows that a penetrating defect on DD ice layer reduces significantly the neutron yield with a YOC of 23.8%. The defect makes the Si-doped CH ablator layer produce a high-amplitude inward-facing spike, penetrating into the central DD gas. A large amount of ablation material is mixed into the hot spot with a mixing mass of 487 ng, leading to a significant increase in the bremsstrahlung radiation loss power from the hot spot compared to the 1D ideal implosion result. It results in a large reduction in the hot-spot temperature and the final DD reaction rate. Meanwhile, the high-density shell spike pushes the hot spot away from the capsule center, exhibiting a great P1 asymmetry. The P1-asymmetric hot spot has an obvious bulk flow velocity, which reduces the conversion efficiency of implosion kinetic energy into the internal energy of the hot spot.