Multi-frame, ultrafast, x-ray microscope for imaging shockwave dynamics
Multi-frame, ultrafast, x-ray microscope for imaging shockwave dynamics
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DOI：
10.1364/oe.472275
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发表时间：
2022-10-10
期刊：
影响因子：
3.8
通讯作者：
Gleason, Arianna E.
中科院分区：
文献类型：
--
作者：
Hodge, Daniel S.;Leong, Ndrew F. T.;Gleason, Arianna E.
惯性约束聚变（ICF）作为一种丰富的清洁能源的潜在来源，前景越来越好，但受到诸如燃料包烧蚀层中的微孔等缺陷的阻碍。了解这些微空隙如何与压缩燃料芯块的激光驱动冲击波相互作用至关重要。在直线加速器相干光源（LCLS）的极端条件下的物质（MEC）仪器中，我们利用具有ns间隔的X射线脉冲串，X射线显微镜和超快X射线成像（UXI）探测器来成像冲击波与微空隙的相互作用。为了最大限度地减少所捕获图像的高频和低频变化，我们结合了主成分分析（PCA）和图像对齐进行平场校正。在应用这些技术后，我们从2D流体动力学辐射代码（xplane）中生成了相位和衰减图，这些代码用于模拟XPCI图像，我们将其与实验图像进行定性比较，为基准材料性能提供一对一的比较。此外，我们实现了运输强度（TIE）为基础的方法，以获得我们的实验图像的平均投影质量密度（面密度），深入了解如何缺陷轴承烧蚀材料改变微观结构特征演变，材料压缩，和冲击波传播ICF相关的时间尺度。(c)2022 Optica出版集团根据Optica开放获取出版协议的条款
Inertial confinement fusion (ICF) holds increasing promise as a potential source of abundant, clean energy, but has been impeded by defects such as micro-voids in the ablator layer of the fuel capsules. It is critical to understand how these micro-voids interact with the laser-driven shock waves that compress the fuel pellet. At the Matter in Extreme Conditions (MEC) instrument at the Linac Coherent Light Source (LCLS), we utilized an x-ray pulse train with ns separation, an x-ray microscope, and an ultrafast x-ray imaging (UXI) detector to image shock wave interactions with micro-voids. To minimize the high-and low-frequency variations of the captured images, we incorporated principal component analysis (PCA) and image alignment for flat-field correction. After applying these techniques we generated phase and attenuation maps from a 2D hydrodynamic radiation code (xRAGE), which were used to simulate XPCI images that we qualitatively compare with experimental images, providing a one-to-one comparison for benchmarking material performance. Moreover, we implement a transport-of-intensity (TIE) based method to obtain the average projected mass density (areal density) of our experimental images, yielding insight into how defect-bearing ablator materials alter microstructural feature evolution, material compression, and shock wave propagation on ICF-relevant time scales. (c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement