X-ray shadow imprint of hydrodynamic instabilities on the surface of inertial confinement fusion capsules by the fuel fill tube.
X-ray shadow imprint of hydrodynamic instabilities on the surface of inertial confinement fusion capsules by the fuel fill tube.
复制标题
惯性约束聚变舱表面由燃料填充管造成的流体动力学不稳定性的 X 射线阴影印记。
作者：
A. MacPhee;D. Casey;D. Clark;S. Felker;J. Field;S. Haan;B. Hammel;J. Kroll;O. Landen;D. Martinez;P. Michel;J. Milovich;A. Moore;A. Nikroo;N. Rice;H. Robey;V. Smalyuk;M. Stadermann;C. Weber
报道了在美国国家点火装置上用于间接驱动惯性约束聚变内爆的高密度碳烧蚀器的水动力不稳定性增长的测量结果。我们观察到由胶囊填充管的阴影在胶囊表面产生的显着的意想不到的特征，正如激光照射在腔壁上的x射线点所照亮的那样。与之前的预期相比，这些阴影增加了填充管扰动的空间大小和形状，从而显著降低了层状内爆的性能。使用飞行中的x射线照相技术以~ 2的收敛比进行测量。据估计，由于阴影印记而产生的初始种子相当于50-100 nm的固体烧蚀材料。这一发现促使我们有必要为未来的惯性约束聚变设计提出一种缓解策略。
Measurements of hydrodynamic instability growth for a high-density carbon ablator for indirectly driven inertial confinement fusion implosions on the National Ignition Facility are reported. We observe significant unexpected features on the capsule surface created by shadows of the capsule fill tube, as illuminated by laser-irradiated x-ray spots on the hohlraum wall. These shadows increase the spatial size and shape of the fill tube perturbation in a way that can significantly degrade performance in layered implosions compared to previous expectations. The measurements were performed at a convergence ratio of ∼2 using in-flight x-ray radiography. The initial seed due to shadow imprint is estimated to be equivalent to ∼50-100 nm of solid ablator material. This discovery has prompted the need for a mitigation strategy for future inertial confinement fusion designs as proposed here.