A5043868765- Advanced X-ray Imaging Techniques
- Adaptive optics and wavefront sensing
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Surface Polishing Techniques
- Advanced Electron Microscopy Techniques and Applications
- Advanced Measurement and Metrology Techniques
- Crystallography and Radiation Phenomena
- Particle Accelerators and Free-Electron Lasers
- Advancements in Photolithography Techniques
- Advanced X-ray and CT Imaging
- Diamond and Carbon-based Materials Research
- Laser-Plasma Interactions and Diagnostics
- Optical Systems and Laser Technology
- Optical measurement and interference techniques
- High-pressure geophysics and materials
- Electron and X-Ray Spectroscopy Techniques
- X-ray Diffraction in Crystallography
- Microstructure and Mechanical Properties of Steels
- Magnetic properties of thin films
- Nuclear Physics and Applications
- Optical Coatings and Gratings
- Magnetic Properties of Alloys
- Surface Roughness and Optical Measurements
- Medical Imaging Techniques and Applications
- Digital Holography and Microscopy
Argonne National Laboratory
2015-2024
Lawrence Berkeley National Laboratory
2023
Advanced Photon Source
2020
Heinz Optical Engineering (United States)
2015
Brookhaven National Laboratory
1999
Cornell University
1992
We have used coherent X-ray diffraction experiments to characterize both the 1-D and 2-D foci produced by nanofocusing Kirkpatrick-Baez (K-B) mirrors, we find agreement.Algorithms related ptychography were obtain a 3-D reconstruction of focused hard beam waist, using data measured when mirrors not optimally aligned.Considerable astigmatism was evident in reconstructed complex wavefield.Comparing wavefield for single mirror with geometrical projection wavefront errors expected from optical...
Nanometer-scale optical imperfections challenge coherent X-ray beam applications, even with advancements in synchrotron facilities, such as the upgraded Advanced Photon Source. Piezoelectric bimorph mirrors offer adaptive control but face limitations from nonlinearities crosstalk, creep, and hysteresis. This work introduces a real-time, feedback-free controller inspired by PID scheme powered tandem neural networks (TNN). Using task-specific datasets, TNN-based system predicts actuator...
A differential coating method is described for fabricating high-performance x-ray microfocusing mirrors. With this method, the figure of ultrasmooth spherical mirrors can be modified to produce elliptical surfaces with low roughness and errors. Submicron focusing demonstrated prototype The deposition creates stiff monolithic which are compact, robust, easy cool align. Prototype have gains more than 104 in beam intensity while maintaining submilliradian divergence on sample. This producing...
We describe progress in the fabrication of short-focal-length total-external-reflection Kirkpatrick-Baez x-ray mirrors with ultralow figure errors. The short focal length optics produce nanoscale beams (<100nm) on conventional (∼64m long) beamlines at third generation synchrotron sources. total-external reflection are inherently achromatic and efficiently focus a white (polychromatic) or tunable monochromatic spectrum x rays. ability to independent wavelength allows novel new...
A new method for beamline simulation combining ray-tracing and wavefront propagation is described. The `Hybrid Method' computes diffraction effects when the beam clipped by an aperture or mirror length can also simulate effect of figure errors in optical elements present. different spatial frequencies on image compared with SHADOW results pointing to limitations latter. code has been benchmarked against multi-electron version SRW one dimension show its validity case fully, partially...
Nanometer-scale optical imperfections challenge coherent X-ray beam applications, even with advancements in synchrotron facilities, such as the upgraded Advanced Photon Source. Piezoelectric bimorph mirrors offer adaptive control but face limitations from nonlinearities crosstalk, creep, and hysteresis. This work introduces a real-time, feedback-free controller inspired by PID scheme powered tandem neural networks (TNN). Using task-specific datasets, TNN-based system predicts actuator...
Nanometer-scale optical imperfections challenge coherent X-ray beam applications, even with advancements in synchrotron facilities, such as the upgraded Advanced Photon Source. Piezoelectric bimorph mirrors offer adaptive control but face limitations from nonlinearities crosstalk, creep, and hysteresis. This work introduces a real-time, feedback-free controller inspired by PID scheme powered tandem neural networks (TNN). Using task-specific datasets, TNN-based system predicts actuator...
Nanometer-scale optical imperfections challenge coherent X-ray beam applications, even with advancements in synchrotron facilities, such as the upgraded Advanced Photon Source. Piezoelectric bimorph mirrors offer adaptive control but face limitations from nonlinearities crosstalk, creep, and hysteresis. This work introduces a real-time, feedback-free controller inspired by PID scheme powered tandem neural networks (TNN). Using task-specific datasets, TNN-based system predicts actuator...
A double-crystal diamond (111) monochromator recently implemented at the Linac Coherent Light Source (LCLS) enables splitting of primary X-ray beam into a pink (transmitted) and monochromatic (reflected) branch. The first crystal, with thickness ∼100 µm, provides sufficient transmittance to enable simultaneous operation two beamlines. This article reports design, fabrication characterization second (300 µm-thick) crystals utilized in optical assemblies holding these crystals. Each crystal...
This article describes the development and testing of a novel, water-cooled, active optic mirror system (called "REAL: Resistive Element Adjustable Length") that combines cooling with applied auxiliary heating, tailored to spatial distribution thermal load generated by incident beam. technique is theoretically capable sub-nanometer surface figure error control even at high power density. Tests conducted in an optical metrology laboratory synchrotron X-ray beamlines showed ability maintain...
We introduce a coded-mask-based multi-contrast imaging method for high-resolution phase-contrast and dark-field imaging. The uses binary phase mask designed to provide an ultra-high-contrast pattern reference-free single-shot measurement algorithm based on maximum-likelihood optimization automatic differentiation perform simultaneous reconstruction of absorption, phase, object images. Further, we demonstrate that the has great potential real-time quantitative wavefront sensing when combined...
A neural-network machine learning model is developed to control a bimorph adaptive mirror achieve and preserve aberration-free coherent X-ray wavefronts at synchrotron radiation free electron laser beamlines. The controller trained on actuator response directly measured beamline with real-time single-shot wavefront sensor, which uses coded mask wavelet-transform analysis. system has been successfully tested deformable the 28-ID IDEA of Advanced Photon Source Argonne National Laboratory. It...
The first test of nanoscale-focusing Kirkpatrick-Baez (KB) mirrors in the nested (or Montel) configuration used at a hard X-ray synchrotron beamline is reported. two are both 40 mm long and coated with Pt to produce focal length 60 3 mrad incident angle, collect up 120 µm by beam maximum angular acceptance 2 broad bandwidth energies 30 keV. In an initial spot about 150 nm horizontal vertical directions was achieved either polychromatic or monochromatic beam. mirror geometry, mounted...
Grating-based X-ray and neutron interferometry tomography using phase-stepping methods generates large data sets. An improved algorithm is presented for solving the parameters to calculate transmissions, differential phase contrast, dark-field images. The method takes advantage of vectorization inherent in high-level languages such as Mathematica MATLAB can solve a 16 × 1k set less than second. In addition, function with partial This demonstrated processing 16-step grating use original...
We developed a portable X-ray grating interferometer setup as standard tool for testing optics at the Advanced Photon Source (APS) beamline 1-BM. The can be operated in phase-stepping, Moiré, or single-grating harmonic imaging mode with 1-D 2-D gratings. All of motions are motorized; hence, it is much easier and quicker to switch between different modes operation. A novel aspect this new instrument its designed portability. While primarily used 1-BM, could potentially deployed other APS...
X-ray phase-contrast imaging has become indispensable for visualizing samples with low absorption contrast. In this regard, speckle-based techniques have shown significant advantages in spatial resolution, phase sensitivity, and implementation flexibility compared traditional methods. However, the computational cost associated data inversion hindered their wider adoption. By exploiting power of deep learning, we developed a neural network (SPINNet) that significantly improves quality boosts...
A cavity-based X-ray free-electron laser (CBXFEL) is a possible future direction in the development of fully coherent sources. CBXFELs consist low-emittance electron source, magnet system with several undulators and chicanes, an cavity. The cavity stores circulates pulses for repeated FEL interactions until reaches saturation. CBXFEL cavities require low-loss wavefront-preserving optical components: near-100%-reflectivity diamond Bragg-reflecting crystals, outcoupling devices such as thin...
Modifications of the long trace profiler at Advanced Photon Source Argonne National Laboratory have significantly improved its accuracy and repeatability for measuring figure large flat long-radius mirrors. Use a Dove prism in reference beam path corrects phasing problems between mechanical errors thermally induced system errors. A single correction now completely removes both these error signals from measured surface profile. The addition precision air conditioner keeps temperature...
Transverse coherence of the x-ray beam from a bending magnet source was studied along multiple directions using 2-D π/2 phase grating by measuring interferogram visibilities at different distances behind grating. These measurements suggest that preferred orientation checkerboard is diagonal square blocks, where interferograms have higher visibility and are not sensitive to deviation duty cycle period. observations verified thorough wavefront propagation simulations. The accuracy measured...
Interfacial reactions and phase transformations play a significant role in the capacity reversibility of lithium batteries. Understanding interfacial structural changes is especially important alloying or conversion found higher-capacity intermetallic metal oxyfluoride systems. Using in-situ X-ray reflectivity, we observe lithiation stratified chromium silicide film with sub-nanometer resolution as model system for characterizing such mechanisms. In-situ reflectivity thin reveals that sample...
A circular grating interferometer was used to map the transverse coherence area of an X-ray beam. Due radial symmetry grating, lengths along all directions were obtained simultaneously by measuring visibility decay interferograms recorded at different distances behind a single π/2 phase grating. The technique is model-free and provides direct measurement complex factor use also enables unique capability source shape profile. Sensitivity this demonstrated detecting small tilt few degrees.
We introduce a new X-ray speckle-vector tracking method for phase imaging, which is based on the wavelet transform. Theoretical and experimental results show that this method, called wavelet-transform-based (WSVT), has stronger noise robustness higher efficiency compared with cross-correlation-based method. In addition, WSVT controllable reduction can be applied fewer scan steps. These unique features make suitable measurements of large image sizes shifts, possibly under low-flux conditions,...