Quantitative Dimension Measurement of ICF Components Using Xradia MicroXCT Microscope
Quantitative Dimension Measurement of ICF Components Using Xradia MicroXCT Microscope
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使用 Xradia MicroXCT 显微镜对 ICF 元件进行定量尺寸测量
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
M. Schoff
中科院分区：
文献类型：
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作者：
H. Huang;S. Eddinger;M. Schoff
摘要国家点火装置（NIF）规范对目标部件有严格的尺寸精度要求。例如，消融器胶囊上的激光孔直径必须表征为±0.5 μm，以确保适当的填充管插入，并将胶接质量最小化至<2.5 ng。使用基于电荷耦合器件的X射线射线照相术和断层摄影仪器（从Xradia，Inc.用于目标计量，其中样品不透明排除使用光学技术;然而，用于尺寸测量的内置卡尺不能提供所需的精度。该仪器有三个主要的误差源：（a）点投影放大率，（B）成像透镜畸变，和（c）相衬偏移。样本特征尺寸决定了校准策略。对于较大的特征，例如髋臼杯直径，（a）和（B）占误差预算的主导地位。内置卡尺的精确度约为2%至3%，相当于2000 μm NIF胶囊的±50 μm误差。在这项工作中，我们开发了一个X射线透射尺寸标准，并开发（通过测量标准）的软件算法，以“不失真”所获得的图像，而不诉诸标准的每一次。后一种方法将处理时间减少了50%，并且仍然提供了十倍的精度提高，使Xradia仪器在筛选组件方面非常有用。对于小的特征，如激光钻孔，（c）是主要的。它移动了表观壁边界，导致5至10 μm孔径的典型~2 μm误差。我们开发了一种经验校正技术，精度为0.5 μm，其中通过射线照相测量的尺寸与样品裂解后通过聚焦离子束和扫描电子显微镜测量的尺寸进行基准比较。改进的准确度允许将胶质量估计为NIF规格要求的1 ng。
Abstract National Ignition Facility (NIF) specifications have stringent dimensional accuracy requirements on target components. For example, the laser-hole diameter on an ablator capsule must be characterized to ±0.5 μm to ensure proper fill tube insertion and to minimize the glue joint mass to <2.5 ng. A charge-coupled-device-based X-ray radiography and tomography instrument (commercially obtained from Xradia, Inc.) is used in target metrology where sample opacity precludes the use of optical techniques; however, the built-in caliper for dimensional measurement cannot provide the required accuracy. The instrument has three main error sources: (a) point projection magnification, (b) imaging lens distortion, and (c) phase contrast shift. The sample feature size dictates the calibration strategy. For large features such as the shell diameter, (a) and (b) dominate the error budget. The built-in caliper is accurate to ~2 to 3%, corresponding to a ±50-μm error for a 2000-μm NIF capsule. In this work, we developed an X-ray transmission dimension standard and developed (by measuring the standard) a software algorithm to “un-distort” the acquired images without resorting to the standard each time. The latter approach reduces the processing time by 50% and still offers a tenfold accuracy improvement and makes the Xradia instrument useful in screening components. For small features such as laser-drilled holes, (c) is dominant. It shifts the apparent wall boundary to cause a typical ~2-μm error for the 5- to 10-μm hole diameter. We developed an empirical correction technique with 0.5-μm accuracy, in which the dimensions measured by radiography were benchmarked against those by a focused ion beam and scanning electron microscope after sample cleavage. The improved accuracy allows the glue mass to be estimated to 1 ng as required by the NIF specifications.