Speaker
Description
The I08-1 soft X-ray ptychography instrument at the Diamond Light Source (UK) is a facility dedicated to the spectro-microscopic and tomographic analysis of the interaction of organic and inorganic matter with unprecedented spatial resolution. It provides capabilities to do Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy for the analysis of transition metals or other elements relevant for biogeochemistry, environmental and earth sciences, medicine and pharmacology, and materials science including magnetism, electrochemistry, catalysis, and battery research.
X-ray ptychography [1] is a lens-less imaging technique that belongs to the family of coherent diffractive imaging methods. During a ptychographic experiment, a series of diffraction images (pattern) is collected in the far-field while a specimen is being raster-scanned with a coherent X-ray beam. Using iterative phase retrieval algorithms, this collection of diffraction pattern is then converted computationally into a reconstructed high-resolution image of the specimen. By repeating the same data collection with a different X-ray energy and/or tomographic rotation angle, this technique can be extended to three-dimensional and spectroscopic imaging [2,3].
In my talk, I am going to present the current capabilities of this new instrument, which is in user operation in optimisation mode since May 2022, as well as give an outline of planned future upgrades. I will describe our current instrumentation and software infrastructure, including an automated live processing pipeline that provides users with a ptychographic reconstruction in near real time by utilising the computational power of graphics cards (GPUs). I will show results from early commissioning experiments where we collected full spectro-ptychograhic data of iron (Fe) nanoparticles across the Fe L3 edge alongside a few scientific examples of early I08-1 users. Spectro-ptychography offers the unique capability to image organic and inorganic samples at high spatial resolution and with chemical specificity, further enhanced by the upcoming upgrade to Diamond II with an expected increase in coherent flux.
References
[1] Pfeiffer, F. (2017) ‘X-ray ptychography’, Nature photonics, 12(1), pp. 9–17.
[2] Dierolf, M. et al. (2010) ‘Ptychographic X-ray computed tomography at the nanoscale’, Nature, 467(7314), pp. 436–439.
[3] Shapiro, D.A. et al. (2014) ‘Chemical composition mapping with nanometre resolution by soft X-ray microscopy’, Nature photonics, 8(10), pp. 765–769.
| Keywords | Ptychography, Coherent Diffractive Imaging, Large Scale Imaging Facilities, Microscopy, Spectroscopy |
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