Ion kinetic effects on the ignition and burn of inertial confinement fusion targets: A multi-scale approach
Ion kinetic effects on the ignition and burn of inertial confinement fusion targets: A multi-scale approach
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离子动力学对惯性约束聚变目标点火和燃烧的影响：多尺度方法
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
V. Tikhonchuk
中科院分区：
文献类型：
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作者：
B. Peigney;O. Larroche;V. Tikhonchuk
在本文中，我们在离子动力学水平上研究了惯性约束聚变弹丸中热核燃料的流体动力学和燃烧。该分析基于双速度尺度 Vlasov-Fokker-Planck 动力学模型，该模型专门用于以与热体自洽的方式处理聚变产物（超热 α 粒子）。该模型假设构型空间中呈球对称性，并且在平均流速周围的速度空间中呈轴对称性。考虑典型的热点点火设计。与应用多组扩散方案来模拟 α 输运的流体模拟相比，全离子动力学方法揭示了对高能 α 粒子输运的显着非局部效应。这对燃烧过程中的流体动力学空间分布有直接影响：热点反应性降低，而内部致密燃料层被逃逸的α-超热粒子预热，这些粒子被输送到远离热点的地方。我们展示了聚变产物的动力学传输增强如何导致聚变产率显着降低。
In this article, we study the hydrodynamics and burn of the thermonuclear fuel in inertial confinement fusion pellets at the ion kinetic level. The analysis is based on a two-velocity-scale Vlasov-Fokker-Planck kinetic model that is specially tailored to treat fusion products (suprathermal α-particles) in a self-consistent manner with the thermal bulk. The model assumes spherical symmetry in configuration space and axial symmetry in velocity space around the mean flow velocity. A typical hot-spot ignition design is considered. Compared with fluid simulations where a multi-group diffusion scheme is applied to model α transport, the full ion-kinetic approach reveals significant non-local effects on the transport of energetic α-particles. This has a direct impact on hydrodynamic spatial profiles during combustion: the hot spot reactivity is reduced, while the inner dense fuel layers are pre-heated by the escaping α-suprathermal particles, which are transported farther out of the hot spot. We show how the kinetic transport enhancement of fusion products leads to a significant reduction of the fusion yield.