Super precision Metrology for Synchrotron X-ray mirrors

同步加速器x射线镜的超精密计量项目目标该项目属于EPSRC工程研究领域，旨在开发一种基于散斑测量技术的新型超精密计量技术。一个同步辐射设备，如钻石光源，可以被视为一个巨大的显微镜，提供连贯和极其明亮的x射线辐射光束，科学家可以用它来研究从化石到喷气发动机到病毒和疫苗的任何东西。反过来，这种光束的成功开发要求光学元件的制造具有非常高的公差。对高精度光学和计量学的要求将对下一代衍射限制存储环提出更高的要求。目前最先进的基于实验室的x射线反射镜测量技术的精度限制在~50-100nrad。为了进一步提高高质量x射线反射镜的光束性能，迫切需要开发一种超精密计量技术。x射线波前传感技术能够以超高的精度精确测量波前及其相关像差。（Sawhney et al., 2013）。近年来，基于x射线散斑的金刚石光源原位镜面测量技术得到了广泛的发展和深入的研究。（Wang， Kashyap和Sawhney， 2015）在该项目中，该技术将从x射线扩展到可见光区域。对精密计量x射线反射镜进行了基于散斑测量仪的光学设计、计算机仿真和实验实现。在可见光波段实施基于散斑的测量技术有可能以前所未有的精度获得x射线反射镜的斜率误差曲线，精度低至20 nrad，这将是同类测量工具中的第一个，并使x射线光学的制造商和用户都受益。该项目由牛津大学和钻石光源有限公司合作完成。参考文献：awhney， K. et al.（2013）“钻石光源的x射线光学波长测量”，同步辐射新闻，26(5)，第17-22页。Wang， H., Kashyap， Y.和Sawhney， K.（2015）“基于散斑的x射线波前传感与纳米辐射角灵敏度”，光学快报，23(18),p. 23310。

Super precision Metrology for Synchrotron X-ray mirrorsProject AimsThis project falls within the EPSRC Engineering research area and aims to develop a novel super-precision metrology based on a speckle based metrology technique.DescriptionA synchrotron radiation facility, such as Diamond Light Source, can be considered as a giant microscope, providing coherent and extremely bright X-ray radiation beams that scientists can use to study anything from fossils to jet engines to viruses and vaccines. In turn, the successful exploitation of such beams requires optical elements to be manufactured to very high tolerances. The requirement for high precision optics and metrology will be even more demanding for the next generation diffraction-limited storage rings.The present state-of-the-art lab-based metrology techniques for X-ray mirrors are limited to a precision of ~50-100nrad. To further improve the beam performance with high quality X-ray mirrors, there is an urgent demand to develop a super precision metrology technique. X-ray wavefront sensing techniques are able to precisely measure the wavefront and the associated aberrations with ultra-high accuracy. (Sawhney et al., 2013). Recently, the X-ray speckle based technique has been extensively developed and intensively studied for in-situ mirror metrology at Diamond Light Source. (Wang, Kashyap and Sawhney, 2015)In the project, the technique will be extended from X-rays to the visible light regime. The optical design, computer simulation and experimental implementation of the speckle-based metrology instrument will be carried out for the precision metrology X-ray mirrors. Implementing the speckle-based metrology technique in the visible light regime has the potential to obtain slope error profiles of X-ray mirrors with unprecedented precisions down to 20 nrad, It would be the first of its kind metrology tool and benefit the manufacturers and users of X-ray optics alike. It will also allow a cheaper and more versatile alternative to characterize x-ray optics mirrors to the other existing techniques This project is under collaboration between the University of Oxford and Diamond Light Source ltd.ReferencesSawhney, K. et al. (2013) 'At-wavelength Metrology of X-ray Optics at Diamond Light Source', Synchrotron Radiation News, 26(5), pp. 17-22.Wang, H., Kashyap, Y. and Sawhney, K. (2015) 'Speckle based X-ray wavefront sensing with nanoradian angular sensitivity', Optics Express, 23(18), p. 23310.