Ptychographic X-ray speckle tracking with multi-layer Laue lens systems
Category
Published on
Type
journal-article
Author
Andrew J. Morgan and Kevin T. Murray and Mauro Prasciolu and Holger Fleckenstein and Oleksandr Yefanov and Pablo Villanueva-Perez and Valerio Mariani and Martin Domaracky and Manuela Kuhn and Steve Aplin and Istvan Mohacsi and Marc Messerschmidt and Karolina Stachnik and Yang Du and Anja Burkhart and Alke Meents and Evgeny Nazaretski and Hanfei Yan and Xiaojing Huang and Yong S. Chu and Henry N. Chapman and Saša Bajt
Citation
Morgan, A.J. et al., 2020. Ptychographic X-ray speckle tracking with multi-layer Laue lens systems. Journal of Applied Crystallography, 53(4), pp.927–936. Available at: http://dx.doi.org/10.1107/s1600576720006925.
Abstract
The ever-increasing brightness of synchrotron radiation sources demands improved X-ray optics to utilize their capability for imaging and probing biological cells, nano-devices and functional matter on the nanometre scale with chemical sensitivity. Hard X-rays are ideal for high-resolution imaging and spectroscopic applications owing to their short wavelength, high penetrating power and chemical sensitivity. The penetrating power that makes X-rays useful for imaging also makes focusing them technologically challenging. Recent developments in layer deposition techniques have enabled the fabrication of a series of highly focusing X-ray lenses, known as wedged multi-layer Laue lenses. Improvements to the lens design and fabrication technique demand an accurate, robust, in situ and at-wavelength characterization method. To this end, a modified form of the speckle tracking wavefront metrology method has been developed. The ptychographic X-ray speckle tracking method is capable of operating with highly divergent wavefields. A useful by-product of this method is that it also provides high-resolution and aberration-free projection images of extended specimens. Three separate experiments using this method are reported, where the ray path angles have been resolved to within 4 nrad with an imaging resolution of 45 nm (full period). This method does not require a high degree of coherence, making it suitable for laboratory-based X-ray sources. Likewise, it is robust to errors in the registered sample positions, making it suitable for X-ray free-electron laser facilities, where beam-pointing fluctuations can be problematic for wavefront metrology.
DOI
Funding
NSF-STC Biology with X-ray Lasers (NSF-1231306)
