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 High intensity X ray Holography written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The crucial physical and technological issues pertaining to the holographic imaging of biological structures with a short-pulse, high-intensity, high-quantum-energy laser were examined. The limitations of x-ray optics are discussed. Alternative holographic techniques were considered, and it was concluded that far-field Fresnel transform holography (Fraunhofer holography) using a photoresist recording surface is most tractable with near term technology. The hydrodynamic expansion of inhomogeneities within the specimen is discussed. It is shown that expansion is the major source of image blurring. Analytic expressions were derived for the explosion of protein concentrations in an x-ray transparent cytoplasm, compared with numerical calculations, and corrections derived to account for the competitive transport processes by which these inhomogeneities lose energy. It is concluded that for the near term Fresnel transform holography, particularly, far-field or Fraunhofer holography, is more practical than Fourier transform holography. Of the alternative fine grain recording media for use with Fresnel transform holography, a photo-resist is most attractive. For best resolution, exposure times must be limited to a few picoseconds, and this calls for investigation of mechanisms to shutter the laser or gate the recording surface. The best contrast ratio between the nitrogen-bearing polymers (protein and the nucleic acids) and water is between the K-edges of oxygen and nitrogen.

Download or read book High intensity X ray Holography written by Johndale C. Solem and published by . This book was released on 1982 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An External Interface for Processing 3 D Holographic and X Ray Images written by Werner Jüptner and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Internationally recognized experts in the field of holographic interferometric testing, X-ray testing, and structural analysis by finite element techniques have come together in ESPRIT project 898 to develop a system that integrates these techniques. This system acts as an external interface between the complementary nondestructive testing methods and computer based structural analysis. In the book the testing and analysis techniques are presented and compared with special emphasis on problems regarding their combination and integration. The architecture and the components of the interface system are described. Experiments proving the feasibility and applicability of the concepts are presented. The chapters of the book dealing with the different techniques are written by the individual partners of the project. A common test object is investigated by all techniques. The book helps the customer to select the testing and analysis method most suitable for his problem. It also presents the background for building up integrated testing equipment for analysis and control.

Download or read book Synchrotron Light Sources and Free Electron Lasers written by Eberhard J. Jaeschke and published by Springer. This book was released on 2016-05-27 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hardly any other discovery of the nineteenth century did have such an impact on science and technology as Wilhelm Conrad Röntgen’s seminal find of the X-rays. X-ray tubes soon made their way as excellent instruments for numerous applications in medicine, biology, materials science and testing, chemistry and public security. Developing new radiation sources with higher brilliance and much extended spectral range resulted in stunning developments like the electron synchrotron and electron storage ring and the freeelectron laser. This handbook highlights these developments in fifty chapters. The reader is given not only an inside view of exciting science areas but also of design concepts for the most advanced light sources. The theory of synchrotron radiation and of the freeelectron laser, design examples and the technology basis are presented. The handbook presents advanced concepts like seeding and harmonic generation, the booming field of Terahertz radiation sources and upcoming brilliant light sources driven by laser-plasma accelerators. The applications of the most advanced light sources and the advent of nanobeams and fully coherent x-rays allow experiments from which scientists in the past could not even dream. Examples are the diffraction with nanometer resolution, imaging with a full 3D reconstruction of the object from a diffraction pattern, measuring the disorder in liquids with high spatial and temporal resolution. The 20th century was dedicated to the development and improvement of synchrotron light sources with an ever ongoing increase of brilliance. With ultrahigh brilliance sources, the 21st century will be the century of x-ray lasers and their applications. Thus, we are already close to the dream of condensed matter and biophysics: imaging single (macro)molecules and measuring their dynamics on the femtosecond timescale to produce movies with atomic resolution.

Download or read book Lensless Holography Methods for Soft X ray Resonant Coherent Imaging written by Diling Zhu and published by Stanford University. This book was released on 2010 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to interpret and inverse x-ray diffraction patterns from crystals has largely shaped our understanding of the structure of matter. However, structure determination of noncrystalline objects from their diffraction patterns is a much more difficult task. The dramatic increase in available coherent x-ray photon flux over the past decade has made possible a technique known as lensless coherent diffractive imaging (CDI), that addresses exactly this problem. The central question around CDI is the so-called phase problem: upon detection of the diffraction intensity, the phase information of the diffracted wave is inevitably lost. Generally, the phase problem is approached using iterative phase retrieval algorithms. Holographic methods, through interference with reference diffractions, encode the phase information directly inside the measured x-ray holograms, and are therefore able to avoid the stagnation and uniqueness problems commonly encountered by the iterative algorithms. This dissertation discusses two novel holographic methods for coherent lensless imaging using resonant soft x-rays. The first part focuses on generalizing the multiple-wavelength anomalous diffraction technique, a highly successful method for solving the crystal structures of biomacromolecules, into a multiple-wavelength holography technique for nanoscale resonant x-ray imaging. Using this method I show element specific reconstructions of nanoparticles and magnetization distribution in magnetic thin films with sub 50 nm resolution. The second part discusses progress in X-ray Fourier holography, an ultrafast lensless imaging platform that can be used with the upcoming x-ray free electron lasers. In particular, I will present experiments using two novel types of extended reference structures that bring the resolution beyond the precision of reference fabrication, previously regarded as the resolution limit for x-ray Fourier transform holography. Finally, future applications of holographic methods, especially experimental considerations for time-resolved studies of nanostructures using X-FELs, will be discussed.

Download or read book Holography written by Fouad Sabry and published by One Billion Knowledgeable. This book was released on 2022-02-21 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: What Is Holography Holography is a technique that enables a wavefront to be recorded and later re-constructed. Holography is best known as a method of generating three-dimensional images, but it also has a wide range of other applications. In principle, it is possible to make a hologram for any type of wave. How You Will Benefit (I) Insights, and validations about the following topics: Chapter 1: Holography Chapter 2: Diffraction Chapter 3: Microscopy Chapter 4: Interferometry Chapter 5: Photorefractive effect Chapter 6: Particle image velocimetry Chapter 7: Holographic data storage Chapter 8: Interference lithography Chapter 9: Rainbow hologram Chapter 10: Holographic interferometry Chapter 11: Digital holography Chapter 12: Computer-generated holography Chapter 13: Volume hologram Chapter 14: Holographic display Chapter 15: Electronic speckle pattern interferometry Chapter 16: Speckle (interference) Chapter 17: Digital holographic microscopy Chapter 18: Holographic optical element Chapter 19: Common-path interferometer Chapter 20: Physics of optical holography Chapter 21: Time-domain holography (II) Answering the public top questions about holography. (III) Real world examples for the usage of holography in many fields. (IV) 17 appendices to explain, briefly, 266 emerging technologies in each industry to have 360-degree full understanding of holography' technologies. Who This Book Is For Professionals, undergraduate and graduate students, enthusiasts, hobbyists, and those who want to go beyond basic knowledge or information for any kind of holography.

Download or read book Development of X ray Holography Methods for Structure Determination written by Yuhao Wang and published by . This book was released on 2012 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Holographic methods show much promise to enable direct determination of atomic structure with minimal assumptions and approximations. The approach can, in principle, provide three dimensional information on atomic positions. However, significant developments in experimental techniques, instrumentation and in data collection and analysis are needed. A review of the holography method is given with a focus on X-ray fluorescence holography. Methods for analysis of X-ray holographic data are also reviewed. An overview of the detectors relevant to X-ray measurements is also presented. An experimental apparatus for rapid acquisition of X-ray holographs using novel X-ray detectors has been developed. The integration of high speed detectors and the utilization of rapid sampling methods to produce high quality holograms form the core of this work. A new method for direct extraction of the electron charge density based on expansion of the hologram with respect to a spherical harmonic basis is developed. This approach attacks the problem of obtaining the electron density from the hologram by the introduction of periodic constraints (fixed unit cells) while maintaining flexibility by making no assumptions about the positions of atoms within the unit cells. Problems with local or long range distortions can be solved by utilizing cells of the appropriate size. The method makes no other assumptions. Model charge densities derived from this approach are shown to match quite well with the input model crystal structures with no need for heavy filtering typical of the Barton Transform. The algorithm can be fully automated and hence falls into the class of "Direct Methods". This new approach may move the method of X-ray holography from the developmental stage to a powerful and routine tool for the solution of single crystal structures relevant to inorganic materials and organic systems.

Download or read book Holographic Materials and Optical Systems written by Izabela Naydenova and published by BoD – Books on Demand. This book was released on 2017-03-22 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Holographic Materials and Optical Systems covers recent research achievements in the areas of volume holographic optical elements and systems, development of functionalized holographic recording materials, and applications in holographic imaging and metrology. Designs of single and multiplexed volume holographic optical elements for laser beam shaping, combining, and redirection are covered, and their properties are studied theoretically and experimentally. The high impact of holography in imaging and metrology is demonstrated by applications spreading from thickness and surface measurements, through antenna metrology and analyzing high-density gradients in fluid mechanics to characterization of live objects in clinical diagnostics. Novel functionalized materials used in dynamic or permanent holographic recording cover photopolymers, photochromics, photo-thermo-refractive glasses, and hybrid organic-inorganic media.

Download or read book X ray Holography of Biological Specimens written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The author reviews the reasons for x-ray imaging of biological specimens and the techniques presently being used for x-ray microscopy. The author points out the advantages of x-ray holography and the difficulties of obtaining the requisite coherence with conventional sources. The author discusses the problems of radiation damage and the remarkable fact that short pulse x-ray sources circumvent these problems and obtain high-resolution images of specimens in the living state. Finally, the author reviews some of the efforts underway to develop high-intensity coherent x-ray sources for the laboratory. 14 references, 5 figures, 2 tables.

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 High Resolution X Ray Lensless Imaging by Differential Holographic Encoding written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray free electron lasers (X-FELs) will soon offer femtosecond pulses of laterally coherent x-rays with sufficient intensity to record single-shot coherent scattering patterns for nanoscale imaging. Pulse trains created by split and- delay techniques even open the door for cinematography on unprecedented nanometer length and femtosecond time scales. A key to real space ultrafast motion pictures is fast and reliable inversion of the recorded reciprocal space scattering patterns. Here we for the first time demonstrate in the x-ray regime the power of a novel technique for lensless high resolution imaging, previously suggested by Guizar-Sicairos and Fienup termed holography with extended reference by autocorrelation linear differential operation, HERALD0. We have achieved superior resolution over conventional x-ray Fourier transform holography (FTH) without sacrifices in SNR or significant increase in algorithmic complexity. By combining images obtained from individual sharp features on an extended reference, we further show that the resolution can be even extended beyond the reference fabrication limits. Direct comparison to iterative phase retrieval image reconstruction and images recorded with state of-the-art zone plate microscopes is presented. Our results demonstrate the power of HERALDO as a favorable candidate for robust inversion of single-shot coherent scattering patterns.

Download or read book Curiosity Oriented Research written by R. D. Medford and published by . This book was released on 1974 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Holography at X ray Wavelengths written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We discuss alternative holographic techniques for imaging microscopic structures with a short-pulse, high intensity, high-quantum-energy laser. We find that Fresnel transform holography using a photoresist for registration of the hologram is most likely to be within the scope of near term technology. Although it has advantages in time gating, using an in-line electron microscope for hologram registration has an unacceptable tradeoff between quantum efficiency and resolution. Fourier transform holography using a reflector to generate the reference beam might be a reasonable alternative using low resolution film, but is necessarily more complicated. We discuss the dependence of the required laser intensity on the resolution sought and on the elastic and absorption cross sections. We conclude that resonant scattering must be used to obtain holograms at reasonable intensities.

Download or read book Radiation Damage and Its Influence on Source Requirements for High Resolution X ray Holography written by and published by . This book was released on 1989 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soft x-ray holography offers the possibility of obtaining high resolution, 3-D images of living cells and organelles therein. To achieve a specified resolution, a certain number of photons must be scattered by the smallest features of interest within the sample. This requires a certain irradiating fluence, the magnitude of which depends on the wavelength of the x rays and the scattering cross- sections of the features. Unfortunately, irradiation of the sample will be accompanied by the absorption of x rays. If the dose is large, the sample will be damaged, possibly compromising the quality of the image. A theoretical study of the scattering and absorption of x rays during the creation of a hologram is described. Using a new prescription for scattering by condensed biological materials (e.g., protein and/or DNA) within the aqueous environment of a cell, we estimate the irradiating fluence required for a certain resolution and the associated sample dose. The relative merits of different x-ray wavelengths are discussed. A wavelength of about 44Å, just outside the water window'' (23.2--43.7Å), appears to be optimal in that the required fluence and dose are minimized, while reasonable x-ray penetrability is maintained. Estimates are given for the minimum source energy required and the maximum duration of an exposure to capture an image before blurring due heat induce motion. The use of colloidal gold tagging can enhance image contrast and reduce the required irradiating fluence and sample damage. 6 refs., 5 figs.

Download or read book Coherent X Ray Optics written by David Paganin and published by Oxford University Press on Demand. This book was released on 2006-01-12 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray optics is undergoing a renaissance, which may be paralleled to that experienced by visible-light optics following the invention of the laser. The associated surge of activity in "coherent" x-ray optics has been documented in this monograph, the first of its type in the field.

Download or read book Holographic X ray Detection written by George Kiyoshi Herring and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to non-destructively image the interior of an object with X-rays has enabled huge advances in science and medicine. X-ray differential phase contrast (DPC) is the next generation in imaging, providing higher contrast for soft materials. However, X-ray DPC suffers from poor X-ray detector resolution. Typical commercial detectors have a fundamental physical tradeoff between image resolution and radiation dose. In this dissertation, I present a new method for X-ray detection that overcomes this fundamental limit. This new method uses photo refractive materials from the field of holography to create a high resolution detector which can, in conjunction with X-ray DPC techniques, measure the absorption and refraction of X-rays as they pass through objects. This new detector operates in three main stages: first, interfering X-rays record a hologram into a photorefractive crystal. Then, this crystal is illuminated with visible light to 'read-out' and digitally record the image. Finally, the crystal is erased with ultraviolet light after the image is collected. The result is an X-ray detector with an order of magnitude improvement in resolution (to 208 lp/mm), an order of magnitude improvement in quantum efficiency (to 80%), and a drastic reduction in production cost.