arXiv subjects

Frank Seiboth

Publications and source records attributed to Frank Seiboth.

9 recordsLinked to original sources

arXiv2026

Fast Ptychographic Near-Field Computed Tomography

Near-field X-ray ptychography enables quantitative three-dimensional imaging with nanometer-scale resolution, but its broader application is limited by long acquisition times - often necessitating cryogenic or vacuum environments - and demanding sample preparation procedures. In this paper, we present a flexible near-field ptychography setup that operates under ambient conditions and features an adjustable geometry for different sample sizes and resolution requirements. By replacing stepwise angular acquisition with a fly-rotation sample motion, the scanning overhead is reduced by a factor of 11, drastically lowering the tomographic scan time. To address the bottleneck in sample preparation, we also introduce a sample milling machine that enables fast preparation of specimen pillars with diameters down to 20 um. By lowering both preparation effort and measurement time while maintaining high spatial resolution, the presented system overcomes key limitations of near-field ptychography and makes quantitative X-ray nanotomography substantially more accessible for biological research.

physics.optics↗

arXiv2026

Free-form diamond refractive optics enable efficient high-energy X-ray nano-imaging

Full-field transmission X-ray microscopy (TXM) enables nondestructive three-dimensional imaging of thick and strongly absorbing materials with high spatial resolution. Such capabilities are essential for understanding structure-function relationships in hierarchical materials, with broad applications in biology, energy conversion, and energy storage. At high photon energies, however, TXM performance is limited by the reduced efficiency of diffractive optics and by the challenge of matching the numerical aperture (NA) of the illumination to that of the objective optics. Here we harness freeform diamond refractive optics to overcome a key illumination-efficiency bottleneck in high-energy TXM, demonstrating full-field nano-imaging at 20 keV with a half-period resolution of 72 nm. The optical system combines a custom-designed diamond refractive beam shaper that produces a uniform near-flat-top illumination at the sample with a 94% efficiency, a moving diffuser placed near the sample to increase the effective illumination NA and improve image quality and resolution, and high-precision aberration-corrected diamond compound refractive lenses as the objective optics. These results establish free-form diamond optics as a powerful route to efficient high-energy TXM, expanding full-field nano-imaging to complex, evolving materials systems and enabling in situ, operando, and tomographic studies under experimentally realistic conditions. Furthermore, it opens new avenues for innovation of joint X-ray optical-digital design for a new generation of high-energy X-ray nano-imaging.

physics.optics↗

arXiv2026

Diamond compound refractive lenses for high energy Dark Field X-ray Microscopy

Compound-refractive lenses (CRL) are a type of x-ray optics that find widespread applications as focusing and imaging lenses. The choice of material is one of the most defining properties of these lenses. In this work, we present a CRL made out of diamond. It provides an advantageous balance between refractivity and absorption, along with good manufacturability. Compared to Be CRLs, it features a higher optical density and thus enables application at higher photon energies without relying on large lens stacks or very small radii of curvature, which are challenging to manufacture. A diamond CRL is characterized for use as an objective for Dark-field X-ray Microscopy (DFXM) at the ID03 beamline of the European Synchrotron Radiation Facility (ESRF) and compared to Al and Be CRLs at 17 keV, 33 keV and 37 keV. Increasing the photon energy in DFXM from 17 keV to 37 keV opens up the possibility to investigate new sample systems, that were previously opaque to low energy x-ray radiation. The capability of the diamond CRL at 33 keV is illustrated through DFXM measurements on two 0.5 mm-thick iron-based samples, which cannot be probed at 17 keV.

cond-mat.mtrl-sci↗

arXiv2024

Design, fabrication, and testing of diamond axicons for X-ray microscopy applications

This work presents the design, fabrication, and experimental validation of a refractive diamond axicon for X-ray beam shaping. The diamond axicon was developed to overcome the limitations of polymer-based axicons particularly for application in Transmission X-ray Microscopy (TXM) systems, offering superior mechanical strength, thermal stability, and radiation resistance, making it ideal for synchrotron applications. The axicon was fabricated using femtosecond laser ablation and tested at 11 keV under various coherence conditions. Results demonstrated that the axicon efficiently transformed the X-ray beam into a ring-shaped profile with over 80% transmission. Simulations confirmed the experimental findings and highlighted the potential for further improvements. This work paves the way for the use of diamond axicons in next-generation synchrotron facilities, with future efforts focusing on optimizing fabrication and testing the axicon in full TXM systems.

physics.optics↗

arXiv2024

X-ray induced grain boundary formation and grain rotation in Bi2Se3

Optimizing grain boundary characteristics in polycrystalline materials can improve their properties. Many processing methods have been developed for grain boundary manipulation, including the use of intense radiation in certain applications. In this work, we used X-ray free electron laser pulses to irradiate single-crystalline bismuth selenide (Bi2Se3) and observed grain boundary formation and subsequent grain rotation in response to the X-ray radiation. Our observations with simultaneous transmission X-ray microscopy and X-ray diffraction demonstrate how intense X- ray radiation can rapidly change size and texture of grains.

cond-mat.mtrl-sci↗

arXiv2024

X-ray Microscopy and Talbot Imaging with the Matter in Extreme Conditions X-ray Imager at LCLS

The last decade has shown the great potential that X-ray Free Electron Lasers (FEL) have to study High Energy Density (HED) physics. Experiments at FELs have made significant breakthroughs in Shock Physics and Dynamic Diffraction, Dense Plasma Physics and Warm Dense Matter Science, using techniques such as isochoric heating, inelastic scattering, small angle scattering and X-ray diffraction. In addition, and complementary to these techniques, the coherent properties of the FEL beam can be used to image HED samples with high fidelity. We present new imaging diagnostics and techniques developed at the Matter in Extreme Conditions (MEC) instrument at Linac Coherent Light Source (LCLS) over the last few years. We show results in Phase Contrast Imaging geometry, where the X-ray beam propagates from the target to a camera revealing its phase, as well as in Direct Imaging geometry, where a real image of the sample plane is produced in the camera with a spatial resolution down to 200 nm. Last, we show an implementation of the Talbot Imaging method allowing both X-ray phase and intensity measurements change introduced by a target with sub-micron resolution.

physics.ins-det↗

arXiv2023

Dark-Field X-ray Microscopy for 2D and 3D imaging of Microstructural Dynamics at the European X-ray Free Electron Laser

Dark field X-ray microscopy (DXFM) can visualize microstructural distortions in bulk crystals. Using the femtosecond X-ray pulses generated by X-ray free-electron lasers (XFEL), DFXM can achieve sub-{\mu}m spatial resolution and <100 fs time resolution simultaneously. In this paper, we demonstrate ultrafast DFXM measurements at the European XFEL to visualize an optically-driven longitudinal strain wave propagating through a diamond single crystal. We also present two DFXM scanning modalities that are new to the XFEL sources: spatially 3D and 2D axial-strain scans with sub-{\mu}m spatial resolution. With this progress in XFEL-based DFXM, we discuss new opportunities to study multi-timescale spatio-temporal dynamics of microstructures.

cond-mat.mes-hall↗

arXiv2018

Ptychographic characterization of polymer compound refractive lenses manufactured by additive technology

The recent success in the development of high precision printing techniques allows one to manufacture free-standing polymer structures of high quality. Two-photon polymerization lithography is a mask-less technique with down to 100 μm resolution that provides full geometric freedom. It has recently been applied to the nanofabrication of X-ray compound refractive lenses (CRLs). In this article we report on the characterization of two sets of CRLs of different design produced by two-photon polymerization induced lithography.

physics.optics↗

arXiv2016

The Phase-Contrast Imaging Instrument at the Matter in Extreme Conditions Endstation at LCLS

We describe the Phase-Contrast Imaging instrument at the Matter in Extreme Conditions (MEC) endstation of the Linac Coherent Light Source. The instrument can image phenomena with a spatial resolution of a few hundreds of nanometers and at the same time reveal the atomic structure through X-ray diffraction, with a temporal resolution better than 100 femtosecond. It was specifically designed for studies relevant to High-Energy-Density Science and can monitor, e.g., shock fronts, phase transitions, or void collapses. This versatile instrument was commissioned last year and is now available to the MEC user community.

physics.ins-det↗