An automated approach to the alignment of compound refractive lenses.
An automated approach to the alignment of compound refractive lenses.
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复合折射透镜的自动对准方法。
DOI：
10.1107/s1600577522004039
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发表时间：
2022-07-01
影响因子：
2.5
通讯作者：
中科院分区：
文献类型：
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作者：
证明了在光束线设备上自动对准复合折射透镜的技术的有效性。该算法是在其整体，沿着数值模拟的结果和实施在先进的光子源在美国阿贡国家实验室。复合折射透镜（CRL）是一种成熟的X射线聚焦光学器件，用于在X射线设施中以多条光束线聚焦光束或对样品成像。虽然CRL已经相当成熟，但是由于厚的透镜轮廓，单个透镜元件的堆叠提供非常小的数值孔径，使得它们比服从薄透镜近似的经典光学透镜更难以对准。这意味着对准必须非常精确，并且对入射光束的变化非常敏感，通常需要定期重新调整。有些小组通过使用工程控制（例如安装光学器件）来规避完整的重新对准程序，这牺牲了光束的一些聚焦精度，即光斑大小或分辨率。虽然这些选择最大限度地减少了设置时间，但也有明显的缺点。这项工作提出了一种新的自动化方法来调整CRL使用一个简单的对齐设备，很容易适应和安装在不同类型的X射线实验或设施。这种方法建立在最近的CRL建模工作，使用基于随机Nelder-Mead（SNM）单纯形法的方法。这种方法的概述和它的有效性证明了与数值模拟，测试在先进的光子源进行的真实的实验，以确认其性能与同步加速器光束。这项工作提供了一个机会，自动化的关键仪器在X射线设施。
The efficacy of an automatic technique to align compound refractive lenses at beamline facilities is demonstrated. The algorithm is presented in its entirety, along with the results of numerical simulations and an implementation at the Advanced Photon Source at Argonne National Laboratory, USA. Compound refractive lenses (CRLs) are established X-ray focusing optics, and are used to focus the beam or image the sample in many beamlines at X-ray facilities. While CRLs are quite established, the stack of single lens elements affords a very small numerical aperture because of the thick lens profile, making them far more difficult to align than classical optical lenses that obey the thin-lens approximation. This means that the alignment must be very precise and is highly sensitive to changes to the incident beam, often requiring regular readjustments. Some groups circumvent the full realignment procedure by using engineering controls (e.g. mounting optics) that sacrifice some of the beam’s focusing precision, i.e. spot size, or resolution. While these choices minimize setup time, there are clear disadvantages. This work presents a new automated approach to align CRLs using a simple alignment apparatus that is easy to adapt and install at different types of X-ray experiments or facilities. This approach builds on recent CRL modeling efforts, using an approach based on the Stochastic Nelder–Mead (SNM) simplex method. This method is outlined and its efficacy is demonstrated with numerical simulation that is tested in real experiments conducted at the Advanced Photon Source to confirm its performance with a synchrotron beam. This work provides an opportunity to automate key instrumentation at X-ray facilities.