Download or read book Wave Optical Simulations of X ray Nano focusing Optics written by Markus Osterhoff and published by Universitätsverlag Göttingen. This book was released on 2012 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Curved x-ray multilayer mirrors focus synchrotron beams down to tens of nano metres. A wave-optical theory describing propagation of two waves in an elliptically curved focusing multilayer mirror is developed in this thesis. Using numerical integration, the layer shapes can be optimised for reflectivity and aberrations. Within this framework, performance of both existing and currently upgraded synchrotron beamlines is simulated. Using a more theoretical model case, limits of the theory are studied. A significant part of this work is dedicated to partial spatial coherence, modelled using the method of stochastic superpositions. Coherence propagation and filtering by x-ray waveguides is shown analytically and numerically. This comprehensive model is put forward that shall help in development and testing of new algorithms for a variety of imaging techniques using coherent x-ray beams. Advanced simulations accounting for real structure effects are compared to experimental data obtained at the GINIX instrument at the coherence beamline P10 at PETRA III, DESY. This thesis presents results of a collaboration between the Georg-August-Universität Göttingen and the European Synchrotron Radiation Facility (ESRF) Grenoble.
Download or read book X ray waveguide optics written by Sarah Hoffmann-Urlaub and published by Göttingen University Press. This book was released on 2017 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern x-ray sources and analysis techniques such as lens less imaging combined with phase retrieval algorithms allow for resolving structure sizes in the nanometer range. For this purpose optics have to be employed, ensuring small focal spot dimensions simultaneously with high photon densities. Furthermore, the wave front behind the optics is required to be smooth enabling for high resolution imaging. Combining all these properties, x-ray waveguides are well suited to perform this task, since the intensity distribution behind the guide is restricted in two dimensions serving as a secondary quasi point-source without wave-front aberrations, showing also a high divergence, suitable for resolving fine features. Importantly, the radiation provided by the waveguide reveals a high degree of coherence, required by many imaging techniques. The waveguide itself consists of an air-filled channel embedded in a solid matrix; typical materials are silicon, germanium or quartz. While the entrance area is nano-sized, the channel length is in the millimeter-range, this way posing challenges to fabricate high aspect ratio geometries. Since the functioning of x-ray waveguides is based on the total reflection at small incident angles, the surface roughness of the channel walls must be as low as possible to avoid scattering and hence loss of intensity. To fulfill these demanding conditions, a process scheme involving spin-coating, electron beam lithography, wet development, reactive ion etching and wafer bonding is optimized within this work. To gain deeper insights into the principle of wave guiding finite difference simulations are performed, also opening access for advanced design considerations such as gratings, tapered and curved channels, or beamsplitters, enabling for constructing novel x-ray tools as for example time delay devices or interferometers. Waveguides in all geometries are tested at synchrotron sources, accomplishing new benchmarks in x-ray optical performance. Here, the x-ray beam leaving the channel, propagates out to a pixel array detector in the far-field region. From the recorded data the intensity distribution in the near-field directly behind the waveguide is reconstructed, revealing an outstanding agreement with the simulations and electron micrographs. Since the radiation field of the waveguide is well-characterized and also tunable to meet the requirements of both the measurement setup and the sample, they are suited of a broad field of applications in coherent x-ray imaging.
Download or read book Nanoscale Photonic Imaging written by Tim Salditt and published by Springer Nature. This book was released on 2020-06-09 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book, edited and authored by a team of world-leading researchers, provides a broad overview of advanced photonic methods for nanoscale visualization, as well as describing a range of fascinating in-depth studies. Introductory chapters cover the most relevant physics and basic methods that young researchers need to master in order to work effectively in the field of nanoscale photonic imaging, from physical first principles, to instrumentation, to mathematical foundations of imaging and data analysis. Subsequent chapters demonstrate how these cutting edge methods are applied to a variety of systems, including complex fluids and biomolecular systems, for visualizing their structure and dynamics, in space and on timescales extending over many orders of magnitude down to the femtosecond range. Progress in nanoscale photonic imaging in Göttingen has been the sum total of more than a decade of work by a wide range of scientists and mathematicians across disciplines, working together in a vibrant collaboration of a kind rarely matched. This volume presents the highlights of their research achievements and serves as a record of the unique and remarkable constellation of contributors, as well as looking ahead at the future prospects in this field. It will serve not only as a useful reference for experienced researchers but also as a valuable point of entry for newcomers.
Download or read book A Dedicated Endstation for Waveguide based X ray Imaging written by Sebastian Kalbfleisch and published by Universitätsverlag Göttingen. This book was released on 2013 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book X Ray Near Field Holography Beyond Idealized Assumptions of the Probe written by Johannes Hagemann and published by Göttingen University Press. This book was released on 2017 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: All images are flawed, no matter how good your lenses, mirrors etc. are. Especially in the hard X-ray regime it is challenging to manufacture high quality optics due to the weak interaction of multi-keV photons with matter. This is a tremendous challenge for obtaining high resolution quantitative X-ray microscopy images. In recent years lensless phase contrast imaging has become an alternative to classical absorptionbased imaging methods. Without any optics, the image is formed only by the free space propagation of the wave field. The actual image has to be formed posteriori by numerical reconstruction methods. Advanced phasing methods enable the experimentalist to recover a complex valued specimen from a single or a set of intensity measurement. This would be the ideal case - reality teaches us that there are no ideal imaging conditions. Describing, understanding and circumventing these non ideal imaging conditions and their effects on X-ray near-field holographic (NFH) imaging are the leitmotifs for this thesis. In NFH the non ideal conditions manifest themselves in the illuminating wave field or probe. The probe generally does not satisfy the canonical assumptions of fully coherent and monochromatic radiation emitted by a point source. The main results of this thesis are compiled as a collection of publications. An approach is shown to reconstruct the probe of a X-ray nano-focus setup by a series of measurements of the probe at varied Fresnel number. The following chapter presents a study concerning the reconstruction efficiency in terms of resolution for near- and far-field based lensless imaging. In the following, the reconstruction scheme for the probe is extended to incorporate the effects of partial coherence in the near field. This enables the recovery of the modal structure of the probe which yields a full description of its coherence properties. Giving up the assumption of temporal stability due to the stochastic pulses, delivered by X-ray free electron lasers, the reconstruction of probe and specimen must be achieved from a single shot. A suitable scheme for this purpose is proposed in this work.
Download or read book Advancing the Characterization of Neuronal Cyto Architecture by X ray Phase Contrast Tomography written by Marina Eckermann and published by Universitätsverlag Göttingen. This book was released on 2021 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: To bring physiology and pathology of the human brain into better micro-anatomical and histological context, studies with different methodologies are required. Established techniques such as electron microscopy or histology show limitations in view of invasiveness, labor-intense and artifact-prone sample preparation, as well as an adequate ratio between resolution and volume throughput. For this reason, X-ray phase-contrast tomography (PC-CT) has been proposed as a three-dimensional non-destructive imaging technique, which requires less effort in sample preparation and can assess larger volumes. Furthermore, it offers quantitative electron density based contrast even for unstained tissue. Up to now, however, PC-CT studies fell short in number of samples, so that structural alterations caused by neurodegenerative diseases cannot be distinguished from physiological inter-subject variations. In this thesis, the scalability of PC-CT with respect to the required number of samples and resolution-to-volume-throughput is demonstrated, and the methodology is advanced with respect to data acquisition, processing and segmentation. In addition to the human cerebellum, cortex and hippocampus are studied. Concerning quantification and analysis of PC-CT data, this work introduces optimal transport analysis to obtain quantitative metrics of the cyto-architecture and to identify changes due to neurodegenerative diseases. For the case of Alzheimer’s disease, this workflow reveals a yet undescribed compactification of granular cells in the human hippocampus. This thesis also provides optimized configurations to study neural tissues with laboratory instrumentation, and – finally – provides new correlative imaging approaches, in particular with scanning electron microscopy.
Download or read book Cone beam x ray phase contrast tomography for the observation of single cells in whole organs written by Martin Krenkel and published by Göttingen University Press. This book was released on 2015 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray imaging enables the nondestructive investigation of interior structures in otherwise opaque samples. In particular the use of computed tomography (CT) allows for arbitrary virtual slices through the object and 3D information about intricate structures can be obtained. However, when it comes to image very small structures like single cells, the classical CT approach is limited by the weak absorption of soft-tissue. The use of phase information, encoded in measureable intensity images by free-space propagation of coherent x-rays, allows a huge increase in contrast, which enables 3D reconstructions at higher resolutions. In this work the application of propagation-based phase-contrast tomography to lung tissue samples is demonstrated in close to in vivo conditions. Reconstructions of the lung structure of whole mice at down to 5 μm resolution are obtained at a selfbuilt CT setup, which is based on a liquid-metal jet x-ray source. To reach even higher resolutions, synchrotron radiation in combination with suitable holographic phase-retrieval algorithms is employed. Due to optimized cone-beam geometry, field of view and resolution can be varied over a wide range of parameters, so that information on different length scales can be achieved, covering several millimeters field of view down to a 3D resolution of 50 nm. Thus, the sub-cellular 3D imaging of single cells embedded in large pieces of tissue is enabled, which paves the way for future biomedical research.
Download or read book Strain And Dislocation Gradients From Diffraction Spatially resolved Local Structure And Defects written by Rozaliya I Barabash and published by World Scientific. This book was released on 2014-04-07 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights emerging diffraction studies of strain and dislocation gradients with mesoscale resolution, which is currently a focus of research at laboratories around the world. While ensemble-average diffraction techniques are mature, grain and subgrain level measurements needed to understand real materials are just emerging. In order to understand the diffraction signature of different defects, it is necessary to understand the distortions created by the defects and the corresponding changes in the reciprocal space of the non-ideal crystals.Starting with a review of defect classifications based on their displacement fields, this book then provides connections between different dislocation arrangements, including geometrically necessary and statistically stored dislocations, and other common defects and the corresponding changes in the reciprocal space and diffraction patterns. Subsequent chapters provide an overview of microdiffraction techniques developed during the last decade to extract information about strain and dislocation gradients. X-ray microdiffraction is a particularly exciting application compared with alternative probes of local crystalline structure, orientation and defect density, because it is inherently non-destructive and penetrating.
Download or read book Towards Synthesis of Micro Nano systems written by Fumihiko Kimura and published by Springer Science & Business Media. This book was released on 2006-10-19 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection of papers, presented at the 11th International Conference on Precision Engineering, offers a broader global perspective on the challenges and opportunities ahead. The discussion encompasses leading-edge technologies and forecasts future trends. Coverage includes advanced manufacturing systems; ultra-precision- and micro-machining; nanotechnology for fabrication and measurement; rapid prototyping and production technology; new materials and advanced processes; computer-aided production engineering; manufacturing process control; production planning and scheduling, and much more.
Download or read book Light and X Ray Optics written by Emil Zolotoyabko and published by Walter de Gruyter GmbH & Co KG. This book was released on 2023-06-19 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contemporary optics is the foundation of many of today’s technologies including various focusing and defocusing devices, microscopies and imaging techniques. Light and X-ray Optis for Materials Scientists and Engineers offers a guide to basic concepts and provides an accessible framework for understanding this highly application-relevant branch of science for materials scientists, physicists, chemists, biologists, and engineers trained in different disciplines. The text links the fundamentals of optics to modern applications, especially for promotion of nanotechnology and life science, such as conventional, near-field, confocal, phase-contrast microscopies and imaging schemes based on interference and diffraction phenomena. Written by a noted expert and experienced instructor, the book contains numerous worked examples throughout to help the reader gain a thorough understanding of the concepts and information presented. The text covers a wide range of relevant topics, including reflection, refraction, and focusing phenomena, wave polarization and birefringence in crystals, optics in negative materials, metamaterials, and photonic structures, holography, light and X-ray interferometry, extensive description of diffraction optics, including dynamical X-ray diffraction, and more.
Download or read book Optimization of Waveguide Optics for Lensless X ray Imaging written by Sven Philip Krüger and published by Universitätsverlag Göttingen. This book was released on 2011 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lensless x-ray imaging is a promising method to determine the three-dimensional structure of material science and biological specimens at the nanoscale. The development of this technique is strongly related to the optimization of x-ray optics since the image formation and object reconstruction depend significantly on the properties of the illumination wave-field. Waveguide optics act as quasi-point sources and enable the spatial and coherent filtering of x-ray beams. Up to now, x-ray waveguides were severely limited in transmission and flux, restricting their use to high-contrast test structures with moderate resolution and long accumulation times. To overcome these limitations, a novel waveguide design with an optimized refractive index profile is presented which significantly minimizes the absorption of the modes propagating inside the waveguide. Experimental results along with simulations show that these two-component planar x-ray waveguides provide small beam cross-sections along with a high photon flux at the exit. By a serial arrangement of two waveguide slices an optimized illumination source has been developed for high-resolution microscopy, as demonstrated in proof-of-concept imaging experiments.
Download or read book Nanofinishing Science and Technology written by Vijay Kumar Jain and published by CRC Press. This book was released on 2016-12-12 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Finishing is the final operation after a part is sized and shaped. Currently in high tech industries, there is a demand for nano level surface finishing of components. This process is done to improve the surface finish, to remove the recast layer, or to remove surface and sub-surface defects. The result is low friction, longer product life, and low power requirements. Equally important is the aesthetic aspect of the product. This subject is growing very fast from the technology as well as a science point of view. Books on this subject are very limited, particularly those ones that deal with both the science as well as the technology aspects.
Download or read book Laser generated Synchrotron and Other Laboratory X ray and EUV Sources Optics and Applications II written by George A. Kyrala and published by SPIE-International Society for Optical Engineering. This book was released on 2005 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of SPIE present the original research papers presented at SPIE conferences and other high-quality conferences in the broad-ranging fields of optics and photonics. These books provide prompt access to the latest innovations in research and technology in their respective fields. Proceedings of SPIE are among the most cited references in patent literature.
Download or read book X Ray Microscopy written by Chris Jacobsen and published by Cambridge University Press. This book was released on 2019-12-19 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete introduction to x-ray microscopy, covering optics, 3D and chemical imaging, lensless imaging, radiation damage, and applications.
Download or read book Hard X ray Microscopy Enhanced by Coherent Image Reconstruction written by Jakob Soltau and published by Universitätsverlag Göttingen. This book was released on 2022 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray microscopy is used to study the structure, dynamics and bulk properties of matter with high spatial resolutions. It is widely applied, from physics and chemistry to material and life sciences. In the past two decades, progress in X-ray microscopy was driven either by improvements in X-ray optics or by improvements in the image reconstruction by using algorithms as computational lenses. In this work both approaches are combined to exploit the advantages of X-ray imaging with a large numerical aperture and the advantages of coherent image reconstruction. It is shown that a combined X-ray microscope using both, advanced optics and algorithms, is neither limited by flawed optics nor by constraints imposed by reconstruction algorithms, which enables to go beyond current limits in resolution and applications. The thesis is structured in four parts. In the first part hard X-ray lenses, so called multilayer zone plates, are simulated to investigate volume diffraction effects within the multilayer structure, and to study the potential for smaller focus sizes and higher efficiencies. In the second part, the multilayer zone plates are characterized and implemented in an X-ray microscope. In the third part, a new imaging scheme is presented, which combines in-line holography and coherent diffractive imaging. This method overcomes the current resolution limit of in-line holography and can achieve super-resolution with respect to the numerical aperture of the illuminating beam. Finally, in the fourth part a multilayer zone plate is used as an objective lens with a known transfer function in a novel coherent full-field imaging experiment based on iterative phase retrieval, for high resolution and quantitative contrast.
Download or read book Advances in X ray EUV Optics Components and Applications written by and published by . This book was released on 2006 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High precision EUV and X ray Optics for Advanced Photon Source Facilities written by Qiushi Huang and published by Frontiers Media SA. This book was released on 2023-02-02 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt:
