Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Phys Rev Lett. 2013 Aug 23;111(8):085004. doi: 10.1103/PhysRevLett.111.085004.
Deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility have demonstrated yields ranging from 0.8 to 7×10(14), and record fuel areal densities of 0.7 to 1.3 g/cm2. These implosions use hohlraums irradiated with shaped laser pulses of 1.5-1.9 MJ energy. The laser peak power and duration at peak power were varied, as were the capsule ablator dopant concentrations and shell thicknesses. We quantify the level of hydrodynamic instability mix of the ablator into the hot spot from the measured elevated absolute x-ray emission of the hot spot. We observe that DT neutron yield and ion temperature decrease abruptly as the hot spot mix mass increases above several hundred ng. The comparison with radiation-hydrodynamic modeling indicates that low mode asymmetries and increased ablator surface perturbations may be responsible for the current performance.
在国家点火装置上进行的氘氚惯性约束聚变内爆实验已经展示了 0.8 到 7×10(14)的产量，并创下了 0.7 到 1.3 g/cm2 的记录燃料面密度。这些内爆使用空心器，用 1.5-1.9 MJ 能量的整形激光脉冲照射。激光峰值功率和峰值功率持续时间、胶囊烧蚀剂掺杂浓度和外壳厚度都有所变化。我们通过测量热点的升高的绝对 X 射线发射来量化烧蚀剂的流体动力学不稳定性混合到热点中的程度。我们观察到，随着热点混合质量超过几百纳克，DT 中子产量和离子温度突然下降。与辐射流体动力学模型的比较表明，低阶不对称和增加的烧蚀剂表面扰动可能是当前性能的原因。
