论文标题
使用稀疏X射线数据检测3D功能的机器学习
Machine Learning for Detection of 3D Features using sparse X-ray data
论文作者
论文摘要
在许多惯性限制融合实验中,不能完全用一个和二维模型完全考虑中子产量和其他参数。这种差异表明,存在三维效应可能是显着的。这些效果的来源包括壳和壳界面中的缺陷,胶囊的填充管以及双壳目标中的关节特征。由于它们具有穿透材料的能力,X射线用于捕获物体的内部结构。诸如计算机断层扫描之类的方法使用数百个投影中的X射线X光片来重建对象的三维模型。在实验环境中,例如国家点火设施和Omega-60,这些观点的可用性很少,在许多情况下,仅包括一条视线。从稀疏视图中对3D对象的数学重建是一个不当的反问题。这些类型的问题通常通过使用先前的信息来解决。神经网络已用于3D重建的任务,因为它们能够编码和利用此先前信息。我们利用六个不同的卷积神经网络从实验数据中产生ICF内爆的不同3D表示。我们利用深层监督来训练神经网络来产生高分辨率的重建。我们使用这些表示形式跟踪胶囊的3D特征,例如烧蚀器,内壳和壳半球之间的关节。一般来说,用不同的先验补充的机器学习是3D重建的一种有前途的方法。
In many inertial confinement fusion experiments, the neutron yield and other parameters cannot be completely accounted for with one and two dimensional models. This discrepancy suggests that there are three dimensional effects which may be significant. Sources of these effects include defects in the shells and shell interfaces, the fill tube of the capsule, and the joint feature in double shell targets. Due to their ability to penetrate materials, X-rays are used to capture the internal structure of objects. Methods such as Computational Tomography use X-ray radiographs from hundreds of projections in order to reconstruct a three dimensional model of the object. In experimental environments, such as the National Ignition Facility and Omega-60, the availability of these views is scarce and in many cases only consist of a single line of sight. Mathematical reconstruction of a 3D object from sparse views is an ill-posed inverse problem. These types of problems are typically solved by utilizing prior information. Neural networks have been used for the task of 3D reconstruction as they are capable of encoding and leveraging this prior information. We utilize half a dozen different convolutional neural networks to produce different 3D representations of ICF implosions from the experimental data. We utilize deep supervision to train a neural network to produce high resolution reconstructions. We use these representations to track 3D features of the capsules such as the ablator, inner shell, and the joint between shell hemispheres. Machine learning, supplemented by different priors, is a promising method for 3D reconstructions in ICF and X-ray radiography in general.