Characterization of Materials through High Resolution Coherent Imaging: High Resolution Characterization of Materials with Phase Contrast Imaging
Sponsored by: TMS Extraction and Processing Division, TMS Structural Materials Division, TMS: Advanced Characterization, Testing, and Simulation Committee, TMS: Materials Characterization Committee
Program Organizers: Richard Sandberg, Brigham Young University; Ross Harder, Argonne National Laboratory; Xianghui Xiao, Brookhaven National Laboratory; Brian Abbey, La Trobe University; Saryu Fensin, Los Alamos National Laboratory; Ana Diaz, Paul Scherrer Institute; Mathew Cherukara, Argonne National Laboratory

Tuesday 8:00 AM
March 21, 2023
Room: Aqua 310A
Location: Hilton

Session Chair: Richard Sandberg, Brigham Young University


8:00 AM  Invited
Imaging Intact Human Organs across the Scales using Hierarchical Phase-contrast Tomography: Peter Lee1; Claire Walsh1; Paul Tafforeau2; Christopher Werlein3; Danny Jonigk3; Maximilian Ackermann4; 1University College London; 2ESRF; 3Hannover Medical School; 4Johannes Gutenberg University Mainz
    Biological organisms, like many materials, are hierarchically structured, spanning from molecules to whole organs via cells and organotypic units. For humans these scales span from the nanometre to the metre, and although there have been significant advances in imaging at both extremes, there is a gap in imaging techniques to span the scale from histology (micron) to clinical CT/MRI (100’s of microns). Using the exceptional coherence and high energy provided by the European Synchrotron Research Facility’s Extremely Bright Source (ESRF-EBS) upgrade to a 4th generation source, we’ve developed a technique that decouples resolution from specimen size. This technique, Hierarchical Phase-Contrast Tomography (HiP-CT), can achieve local cellular resolution of soft-tissues using phase propagated information. Specifically, 1 um voxels were achieved locally in a range of intact 150 mm diameter human organs, including the brain, heart, lung, kidney and spleen. The same techniques are applicable to materials see Human-Organ-Atlas.esrf.eu.

8:30 AM  
Resolving the Morphology of a Polyphase Solidification Pattern via In-situ Nanotomography: Paul Chao1; Aramanda Kiran1; Ashwin Shahani1; 1University of Michigan
    Uncovering the morphology of evolving, nano-scale structures like eutectics remains a challenge for experimental measurements. High-speed, full-field x-ray imaging provides unprecedented spatial and temporal resolutions to uncover the solidification process in metal eutectic alloys. However, reconstructing the 3D volume from one or a limited set of angular projections remains a challenge for X-ray nanotomography and novel imaging strategies are needed to overcome this limitation. Here we present initial results captured at the National Synchrotron Light Source-II at Brookhaven National Laboratory to resolve the unusual solidification dynamics of an Al-Al3Ni eutectic alloy, which contains a small volume fraction of an anisotropic Al3Ni phase embedded in an Al matrix. Through advancements in data sampling and reconstruction, we maximize the performance of the available in-situ nanotomography instrumentation to characterize these fine polyphase structures evolving from the molten state.

8:50 AM  
Imaging Laser Shockwave Dynamics in Defect-bearing Ablator Materials: Daniel Hodge1; Silvia Pandolfi2; Andrew Leong3; David Montgomery3; Arianna Gleason2; Richard Sandberg1; 1Brigham Young University; 2SLAC National Laboratory; 3Los Alamos National Laboratory
    Material design and fabrication are two factors that have advanced fusion energy research in the past decade. However, material defects in ablators, such as micro-voids that arise from fabrication processes, causes degradation to energy yield in inertial confinement fusion (ICF) experiments, hindering fusion energy progress. At the Matter in Extreme Conditions instrument at the Linac Coherent Light Source we combine femtosecond x-ray pulses with laser driven shock compression to analyze the shock response of ICF-related materials such as low-density polymers containing hollow silica micro-voids. We image the inhomogeneities in the shock front, giving insight into the void collapse process in extreme conditions at the micron scale. To minimize the influence of low- and high-frequency artifacts in the images, we incorporate principal component analysis and image alignment. By performing phase retrieval on the flat-field corrected images we can obtain the areal density of a dynamically compressed material from a single image.

9:10 AM  
Precise Registration Algorithm for High-resolution Imaging Applications: Xianghui Xiao1; Zhengrui Xu2; Dong Hou2; Zhijie Yang2; Feng Lin2; 1Brookhaven National Laboratory; 2Virginia Tech
    Image registration is broadly used in various scenarios in which similar scenes in different images are to be aligned. However, image registration becomes challenging when the contrasts and backgrounds in the images are vastly different. This work proposes using the total variation of the difference map between two images (TVDM) as a dissimilarity metric in rigid registration. A method based on TVDM minimization is implemented for image rigid registration. The method is tested with synthesized and real experimental data with various noise and background conditions. The performance of the proposed method is compared with the results of other rigid registration methods. It is demonstrated that the proposed method is highly accurate and robust and outperforms other methods in all the tests. The new algorithm provides a robust option for image registrations critical to many nano-scale imaging and microscopy applications.

9:30 AM Break

9:50 AM  
Solving Complex Structures with Electron Ptychography: Yu-Tsun Shao1; Zhen Chen1; Yi Jiang1; Chenyu Zhang1; Harikrishnan K.P.1; David Muller1; 1Cornell University
     Electron microscopy is a widespread and often essential tool for structural and chemical analysis at the atomic level. The ultimate limit to spatial resolution in an electron microscope is set by the thermal vibrations of the atoms themselves, which are on the order of 10-20 pm. By combining the full 4D-phase space information (4D-STEM) and multislice electron ptychography algorithm, we are now able to see the details of thermal vibrations of individual atom columns. Furthermore, this also allows for 3D structure determination for both light and heavy elements.The improved resolution, dose efficiency enabled by ptychography make it easy to identify defects such as sulfur monovacancies, or shear distortions in twisted bilayers. For oxide heterostructures, we demonstrate the 3D imaging of a single Tm dopant atom in Gd3Ga5O12 samples, as well as determine complex polar textures and octahedral tilts in BiFeO3/TbScO3 superlattices and NaNbO3 thin films.

10:10 AM  Invited
MHz Microscopy at European XFEL: Patrik Vagovic1; Pablo Villanueva Perez2; Tokushi Sato3; Valerio Bellucci3; Sarlota Birsteinova3; Henry Kirkwood3; Richard Bean3; Romain Letrun3; Jayanath Koliyadu3; Rita Graceffa3; Antonio Bonucci3; Adrian Mancuso3; Alke Meents1; Henry Chapman1; 1Center for Free Electron Laser Science, DESY; 2Lund University; 3European XFEL
    MHz rate fourth generation hard X-ray XFEL source European XFEL provide opportunity for characterisation of stochastic dynamics occurring in various systems. High repetition rate of pulses together with high flux per pulse allow to record projected X-ray radiograms of dynamic samples and image more then million frames per second with high resolution. Each such frame is illuminated using ultrashort exposure given by the X-ray pulse duration providing “frozen in time” snapshots of stochastic phenomena. This enable to film fast stochastic processes individual realisations in slow smooth motion. The unique performance allows for implementation of X-ray beam splitting schemes of multiprotection microscopy to obtain 3D snapshots per single pulse of dynamic objects sampled at MHz rate. We will present applications of recently developed MHz XFEL projection X-ray microscopy and present multi-projection MHz X-ray which is being developed under EIC-Pathfinder MHz-Tomoscopy project at SPB/SFX instrument.

10:40 AM  
Ultrafast Dark-field X-ray Microscopy – A New Tool for Multiscale Analysis : Leora Dresselhaus-Marais1; 1Stanford University
    Defects and structural distortions dictate important hierarchical crystalline and defect dynamics in metals and functional materials. But many processes – from fracture to phase transitions – have dynamics that depend on multiscale dynamics that are difficult to reconcile between mm-A lengthscales and ms-ps timescales. Dark-field X-ray microscopy (DFXM) can now directly image defects in single- and poly-crystals, resolving distortions deep beneath the surface over a wide field of view, with high sensitivity to strain and inclination in the lattice. We have developed time-resolved DFXM over the past 5 years for multiscale analysis of dynamics, and recently extended this to ultrafast timescales at X-ray free electron lasers. I will present the new DFXM toolbox we have developed and demonstrate how it informs dislocation dynamics and thermal engineering. Our DFXM experiments can now collect movies of mesoscale deformation processes in-situ over ms-fs timescales, offering key opportunities to inform models yet untested.

11:00 AM  
Coherent Surface Scattering Imaging with Nanometer Resolution for 3D Mesoscale Structures at Surfaces and Interfaces: Zhang Jiang1; Peco Myint1; Ashish Tripathi1; Miaoqi Chu1; Mathew Cherukara1; Suresh Narayanan1; Nicholas Schwarz1; Jin Wang1; 1Argonne National Lab
    Coherent surface scattering imaging (CSSI) is a recently developed high-resolution non-destructive X-ray imaging technique for imaging supported nanostructures at surfaces and buried interfaces. CSSI takes advantage of the established coherent imaging techniques in transmission geometry, such as CDI and ptychography, but operates in grazing-angle geometry and thus can potentially probe non-periodic nano-features in thin-film based 3D systems. A one-of-a-kind CSSI beamline is being developed as a featured beamline for the APS Upgrade. In this talk, I will present the progress of the dedicated CSSI beamline, as well as the CSSI methodology and imaging reconstruction.