The effects of convergence ratio on the implosion behavior of DT layered inertial confinement fusion capsules
The effects of convergence ratio on the implosion behavior of DT layered inertial confinement fusion capsules
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DOI：
10.1063/1.4993065
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发表时间：
2017-07-01
影响因子：
2.2
通讯作者：
Shah, R. C.
中科院分区：
文献类型：
--
作者：
Haines, Brian M.;Yi, S. A.;Shah, R. C.
用于惯性约束聚变舱的湿泡沫舱设计，包括用氘氚液体润湿的泡沫层，使得在国家点火装置上具有宽范围的热点会聚比（CR）的分层舱内爆成为可能。我们提出了一个全尺寸的湿泡沫胶囊设计，表现出高增益的一维模拟。在这些模拟中，由于更高的热点温度和增加的燃料面密度，增加收敛比导致改进的胶囊产率。这种设计的高分辨率二维模拟提出了详细的和良好的解决模型的胶囊填充管，支持帐篷，表面粗糙度，并预测在X射线驱动器的不对称性。我们的模型，这些不对称性进行了验证与现有的实验数据的比较。在全尺寸润湿泡沫胶囊设计的2D模拟中，由填充管引起的喷射通过由于预热而导致的钨掺杂壳层的膨胀来防止。虽然表面粗糙度和预测的X射线驱动器中的不对称性的影响通过收敛效应而增强，但在高CR下在2D中可能预测不足，模拟预测胶囊对这些特征具有鲁棒性。然而，该设计非常容易受到胶囊支撑帐篷的影响，这否定了增加会聚比的所有一维益处。事实上，当支撑帐篷包括在模拟中时，当CR > 20时，产量随着收敛比的增加而降低。尽管如此，结果表明，全尺寸湿泡沫设计有可能优于冰层胶囊，因为当在低收敛比（CR < 20）下现场时，目前可实现的不对称水平。由AIP出版社出版。
The wetted foam capsule design for inertial confinement fusion capsules, which includes a foam layer wetted with deuterium-tritium liquid, enables layered capsule implosions with a wide range of hot-spot convergence ratios (CR) on the National Ignition Facility. We present a full-scale wetted foam capsule design that demonstrates high gain in one-dimensional simulations. In these simulations, increasing the convergence ratio leads to an improved capsule yield due to higher hot-spot temperatures and increased fuel areal density. High-resolution two-dimensional simulations of this design are presented with detailed and well resolved models for the capsule fill tube, support tent, surface roughness, and predicted asymmetries in the x-ray drive. Our modeling of these asymmetries is validated by comparisons with available experimental data. In 2D simulations of the full-scale wetted foam capsule design, jetting caused by the fill tube is prevented by the expansion of the tungsten-doped shell layer due to preheat. While the impacts of surface roughness and predicted asymmetries in the x-ray drive are enhanced by convergence effects, likely underpredicted in 2D at high CR, simulations predict that the capsule is robust to these features. Nevertheless, the design is highly susceptible to the effects of the capsule support tent, which negates all of the one-dimensional benefits of increasing the convergence ratio. Indeed, when the support tent is included in simulations, the yield decreases as the convergence ratio is increased for CR > 20. Nevertheless, the results suggest that the full-scale wetted foam design has the potential to outperform ice layer capsules given currently achievable levels of asymmetries when fielded at low convergence ratios (CR < 20). Published by AIP Publishing.