Super precision Metrology for Synchrotron X-ray mirrors

Lead Research Organisation: University of Oxford
Department Name: Engineering Science

Abstract

Super precision Metrology for Synchrotron X-ray mirrors
Project Aims
This project falls within the EPSRC Engineering research area and aims to develop a novel super-precision metrology based on a speckle based metrology technique.
Description
A 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.
References
Sawhney, 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.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/R513295/1 01/10/2018 30/09/2023
2293534 Studentship EP/R513295/1 01/10/2019 30/09/2023 Simone Moriconi