论文标题
通过人工神经网络朝着反射率概况反转
Towards Reflectivity profile inversion through Artificial Neural Networks
论文作者
论文摘要
镜面中子和X射线反射仪的目标是从实验反射率曲线中推断材料散射长度密度(SLD)曲线。本文着重研究涉及使用人工神经网络(ANN)的原始方法的原始方法。特别是,此处描述的数值实验涉及大量的模拟反射率曲线和SLD配置文件的数据集,并旨在评估数据科学和机器学习技术在中子散射大规模设施中生成的数据分析的适用性。已经证明,在某些情况下,经过适当训练的深度神经网络能够正确恢复合理的SLD概况,而在未观察到的反射率曲线之前就可以正确恢复。 When the necessary conditions are met, a proper implementation of the described approach would offer two main advantages over traditional fitting methods when dealing with real experiments, namely, 1. sample physical models are described under a new paradigm: detailed layer-by-layer descriptions (SLDs, thicknesses, roughnesses) are replaced by parameter free curves $ρ(z)$, allowing a-priori assumptions to be fed in terms of the sample family to which a给定的样品属于(例如“薄膜”,“层状结构”等)2。按数量级缩小时间缩小的时间,从而可以更快地对大数据集进行批处理分析。
The goal of Specular Neutron and X-ray Reflectometry is to infer materials Scattering Length Density (SLD) profiles from experimental reflectivity curves. This paper focuses on investigating an original approach to the ill-posed non-invertible problem which involves the use of Artificial Neural Networks (ANN). In particular, the numerical experiments described here deal with large data sets of simulated reflectivity curves and SLD profiles, and aim to assess the applicability of Data Science and Machine Learning technology to the analysis of data generated at neutron scattering large scale facilities. It is demonstrated that, under certain circumstances, properly trained Deep Neural Networks are capable of correctly recovering plausible SLD profiles when presented with never-seen-before simulated reflectivity curves. When the necessary conditions are met, a proper implementation of the described approach would offer two main advantages over traditional fitting methods when dealing with real experiments, namely, 1. sample physical models are described under a new paradigm: detailed layer-by-layer descriptions (SLDs, thicknesses, roughnesses) are replaced by parameter free curves $ρ(z)$, allowing a-priori assumptions to be fed in terms of the sample family to which a given sample belongs (e.g. "thin film", "lamellar structure", etc.) 2. the time-to-solution is shrunk by orders of magnitude, enabling faster batch analyses for large datasets.