Download or read book Soft X ray Coherence and Coherent Diffractive Imaging written by Mr. Ramon Rick and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The increased brightness of third-generation synchrotron X-ray sources using undulator insertion devices has opened up new fields for coherent lensless imaging experiments. While in the optical regime, coherent light sources allowed the pursuit of holography and imaging of non-periodic micron-sized objects, hard X-ray crystallography relied on the constructive interference of periodic lattices to image atomic structures. In the intermediate regime of soft X-rays, we now have the capability to coherently image non-periodic nanoscopic structures. Several elemental resonances, from carbon, nitrogen and oxygen to iron, cobalt and nickel, fall into the soft X-ray range of 100 eV to 1 keV. In order to pursue soft X-ray coherent imaging experiments at a synchrotron, an understanding of the origin of coherence is required. The first part of this work thus addresses the coherence properties of the undulator source. Imaging in this regime is both photon and spatial coherence thirsty and there is an inherent trade-off between these two resources. The incoherent source structure and the Heisenberg uncertainty principle lie at the heart of this matter. In reconstructing images of materials from intensity diffraction patterns, one faces the well-known phase problem. The second part of this work addresses two imaging techniques that were extended to the imaging of magnetic domains using X-ray magnetic circular dichroism. Fourier transform holography encodes the lost phase information into the intensity diffraction pattern, while multi-wavelength anomalous diffraction utilizes the energy dependence of the material's refractive index to regain the phase information. This latter method simplifies the sample preparation process and has the potential for coherent scanning microscopy.

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 Coherent X Ray Optics written by David Paganin and published by OUP Oxford. This book was released on 2006-01-12 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a thorough treatment of the rapidly-expanding field of coherent x-ray optics, which has recently experienced something of a renaissance with the availability of third-generation synchrotron sources. It is the first book of its kind. The author begins with a treatment of the fundamentals of x-ray diffraction for both coherent and partially coherent radiation, together with the interactions of x-rays with matter. X-ray sources, optics elements and detectors are then discussed, with an emphasis on their role in coherent x-ray optics. Various facets of coherent x-ray imaging are then discussed, including holography, interferometry, self imaging, phase contrast and phase retrieval. Lastly, the foundations of the new field of singular x-ray optics are examined. Most topics are developed from first principles, with numerous references given to the contemporary research literature. This book will be useful to x-ray physicists and students, together with optical physicists and engineers who wish to learn more about the fascinating subject of coherent x-ray optics.

Download or read book Ultrafast Coherent Diffractive Imaging at FLASH written by H. N. Chapman and published by . This book was released on 2006 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using the FLASH facility we have demonstrated high-resolution coherent diffractive imaging with single soft-X-ray free-electron laser pulses [1]. The intense focused FEL pulse gives a high resolution low-noise coherent diffraction pattern of an object before that object turns into a plasma and explodes. Our experiments are an important milestone in the development of single-particle diffractive imaging with future X-ray free-electron lasers [2, 3]. Our apparatus provides a new and unique tool at FLASH to perform imaging of biological specimens beyond conventional radiation damage resolution limits [2, 4] and to acquire images of ultrafast processes initiated by an FEL pulse or other laser pulse. Coherent diffractive imaging is an ideal method for high-resolution ultrafast imaging with an FEL. Since no optical element is required, the method can in principle be scaled to atomic resolution with short enough wavelength. Spatial and temporal coherence are necessary to ensure that the scattered light waves from all positions across the sample are correlated when they interfere at the detector, giving rise to a coherent diffraction pattern that can be phased and inverted to give a high-resolution image of the sample. In contrast to crystals, where scattering from the many unit cells constructively interfere to give Bragg spots, the coherent diffraction pattern of a non-periodic object is continuous. Such a coherent diffraction pattern contains as much as twice the information content of the pattern of its crystallized periodic counterpart--exactly the amount of information needed to solve the phase problem and deterministically invert the pattern to yield an image of the object [5, 6]. The computer algorithm that performs this function replaces the analogue computations of a lens: summing the complex-valued amplitudes of scattered waves to form an image at a particular plane. Our experimental geometry is shown in Fig. 1. We focus a coherent X-ray pulse from the FLASH source onto the sample and record the far-field diffraction pattern of the object on an area detector (a direct-detection CCD chip) centered on the forward direction. The CCD is protected from destruction by the intense forward scattered beam by a mirror that reflects only the diffracted light onto the detector; the direct beam harmlessly passes through a hole in the mirror. The mirror is coated with a resonant X-ray multilayer coating. We fabricated the coating so that the layer period varies across the mirror in such a way that only in-band X-rays propagating from near the sample interaction point are efficiently reflected. In this way the mirror is a very effective filter that rejects noise such as broadband emission from the sample (e.g. when it turns into a plasma and explodes) and off-axis stray light from scattering and emission of beam line components. This arrangement was crucial here to record clean single-pulse diffraction patterns that could be phased and inverted.

Download or read book Coherent X ray diffractive imaging on the single cell level of microbial samples written by Robin Niklas Wilke and published by Göttingen University Press. This book was released on 2015 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its first experimental demonstration in 1999, Coherent X-Ray Diffractive Imaging has become one of the most promising high resolution X-Ray imaging techniques using coherent radiation produced by brilliant synchrotron storage rings. The ability to directly invert diffraction data with the help of advanced algorithms has paved the way for microscopic investigations and wave-field analyses on the spatial scale of nanometres without the need for inefficient imaging lenses. X-Ray phase contrast which is a measure of the electron density is an important contrast mode of soft biological specimens. For the case of many dominant elements of soft biological matter, the electron density can be converted into an effective mass density offering a unique quantitative information channel which may shed light on important questions such as DNA compaction in the bacterial nucleoid through ‚weighing with light‘. In this work X-Ray phase contrast maps have been obtained from different biological samples by exploring different methods. In particular, the techniques Ptychography and Waveguide-Holographic-Imaging have been used to obtain twodimensional and three-dimensional mass density maps on the single-cell-level of freeze-dried cells of the bacteria Deinococcus radiodurans, Bacillus subtilis and Bacillus thuringiensis allowing, for instance, to estimate the dry weight of the bacterial genome in a near native state. On top of this, reciprocal space information from coherent small angle X-Ray scattering (cellular Nano-Diffraction) of the fine structure of the bacterial cells has been recorded in a synergistic manner and has been analysed down to a resolution of about 2.3/nm exceeding current limits of direct imaging approaches. Furthermore, the dynamic range of present detector technology being one of the major limiting factors of ptychographic phasing of farfield diffraction data has been significantly increased. Overcoming this problem for the case of the very intense X-Ray beam produced by Kirkpatrick-Baez mirrors has been explored by using semi-transparent central stops.

Download or read book Contrast and Resolution Enhancement Techniques for Soft X ray Microscopy written by Anne Eugenie Sakdinawat and published by . This book was released on 2008 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soft X Rays and Extreme Ultraviolet Radiation written by David Attwood and published by Cambridge University Press. This book was released on 2007-02-22 with total page 611 pages. Available in PDF, EPUB and Kindle. Book excerpt: This detailed, comprehensive book describes the fundamental properties of soft X-rays and extreme ultraviolet (EUV) radiation and discusses their applications in a wide variety of fields, including EUV lithography for semiconductor chip manufacture and soft X-ray biomicroscopy. The author begins by presenting the relevant basic principles such as radiation and scattering, wave propagation, diffraction, and coherence. He then goes on to examine a broad range of phenomena and applications. The topics covered include spectromicroscopy, EUV astronomy, synchrotron radiation, and soft X-ray lasers. The author also provides a wealth of useful reference material such as electron binding energies, characteristic emission lines and photo-absorption cross-sections. The book will be of great interest to graduate students and researchers in engineering, physics, chemistry, and the life sciences. It will also appeal to practising engineers involved in semiconductor fabrication and materials science.

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 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 Coherent Hard X ray Focusing Optics and Applications written by and published by . This book was released on 1991 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coherent hard x-ray beams with a flux exceeding 109 photons/second with a bandwidth of 0.1% will be provided by the undulator at the third generation synchrotron radiation sources such as APS, ESRF, and Spring-8. The availability of such high flux coherent x-ray beams offers excellent opportunities for extending the coherence-based techniques developed in the visible and soft x-ray part of the electromagnetic spectrum to the hard x-rays. These x-ray techniques (e.g., diffraction limited microfocusing, holography, interferometry, phase contrast imaging and signal enhancement), may offer substantial advantages over non-coherence-based x-ray techniques currently used. For example, the signal enhancement technique may be used to enhance an anomalous x-ray or magnetic x-ray scattering signal by several orders of magnitude. Coherent x-rays can be focused to a very small (diffraction-limited) spot size, thus allowing high spatial resolution microprobes to be constructed. The paper will discuss the feasibility of the extension of some coherence-based techniques to the hard x-ray range and the significant progress that has been made in the development of diffraction-limited focusing optics. Specific experimental results for a transmission Fresnel phase zone plate that can focus 8.2 keV x-rays to a spot size of about 2 microns will be briefly discussed. The comparison of measured focusing efficiency of the zone plate with that calculated will be made. Some specific applications of zone plates as coherent x-ray optics will be discussed. 17 refs., 4 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 X Rays and Extreme Ultraviolet Radiation written by David Attwood and published by Cambridge University Press. This book was released on 2017-02-16 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With this fully updated second edition, readers will gain a detailed understanding of the physics and applications of modern X-ray and EUV radiation sources. Taking into account the most recent improvements in capabilities, coverage is expanded to include new chapters on free electron lasers (FELs), laser high harmonic generation (HHG), X-ray and EUV optics, and nanoscale imaging; a completely revised chapter on spatial and temporal coherence; and extensive discussion of the generation and applications of femtosecond and attosecond techniques. Readers will be guided step by step through the mathematics of each topic, with over 300 figures, 50 reference tables and 600 equations enabling easy understanding of key concepts. Homework problems, a solutions manual for instructors, and links to YouTube lectures accompany the book online. This is the 'go-to' guide for graduate students, researchers and industry practitioners interested in X-ray and EUV interaction with matter.

Download or read book Elements of Modern X ray Physics written by Jens Als-Nielsen and published by John Wiley & Sons. This book was released on 2011-04-04 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eagerly awaited, this second edition of a best-selling text comprehensively describes from a modern perspective the basics of x-ray physics as well as the completely new opportunities offered by synchrotron radiation. Written by internationally acclaimed authors, the style of the book is to develop the basic physical principles without obscuring them with excessive mathematics. The second edition differs substantially from the first edition, with over 30% new material, including: A new chapter on non-crystalline diffraction - designed to appeal to the large community who study the structure of liquids, glasses, and most importantly polymers and bio-molecules A new chapter on x-ray imaging - developed in close cooperation with many of the leading experts in the field Two new chapters covering non-crystalline diffraction and imaging Many important changes to various sections in the book have been made with a view to improving the exposition Four-colour representation throughout the text to clarify key concepts Extensive problems after each chapter There is also supplementary book material for this title available online (http://booksupport.wiley.com). Praise for the previous edition: “The publication of Jens Als-Nielsen and Des McMorrow’s Elements of Modern X-ray Physics is a defining moment in the field of synchrotron radiation… a welcome addition to the bookshelves of synchrotron–radiation professionals and students alike.... The text is now my personal choice for teaching x-ray physics…” – Physics Today, 2002

Download or read book A Study on New Approaches in Coherent X ray Microscopy of Biological Specimens written by Klaus Giewekemeyer and published by Universitätsverlag Göttingen. This book was released on 2011 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of coherent x rays for microscopic imaging has seen a rapid and ongoing development within the past decade, driven by an increasing availability of highly brilliant and coherent sources worldwide. Accordingly, novel methods have been developed, which replace the microscope‘s objective lens by a numerical reconstruction scheme. The aim of the present work is to study how very recent experimental and algorithmic developments in the field can be implemented towards a highly sensitive and fully quantitative microscopy method for imaging of biological cells. To this end, different experimental approaches are studied, based on coherent far-field as well as near-field diffraction. At first, an application of the novel ptychographic imaging method to single biological cells is presented. In particular, it is demonstrated how weakly scattering biological specimens can be imaged with fully quantitative density contrast. Alongside, a sueccessful extension of the method towards soft x-ray energies is described.In the second part of the work it is shown how x-ray waveguides can be used as a point source for propagation-based microscopy of single cells in the hard x-ray regime. The specifically devised iterative reconstruction scheme allows for full quantitativity and high sensitivity and thus enables an application to single biological cells. The work contains a thorough introduction into the x-ray optical methods applied and aims at a useful and self-contained overview on aspects of signal and Fourier theory relevant for the used numerical propagation schemes.

Download or read book 21st Century Nanoscience A Handbook written by Klaus D. Sattler and published by CRC Press. This book was released on 2020-04-02 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: This up-to-date reference is the most comprehensive summary of the field of nanoscience and its applications. It begins with fundamental properties at the nanoscale and then goes well beyond into the practical aspects of the design, synthesis, and use of nanomaterials in various industries. It emphasizes the vast strides made in the field over the past decade – the chapters focus on new, promising directions as well as emerging theoretical and experimental methods. The contents incorporate experimental data and graphs where appropriate, as well as supporting tables and figures with a tutorial approach.

Download or read book X Ray Diffraction Imaging written by Joel Greenberg and published by CRC Press. This book was released on 2018-11-02 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores novel methods for implementing X-ray diffraction technology as an imaging modality, which have been made possible through recent breakthroughs in detector technology, computational power, and data processing algorithms. The ability to perform fast, spatially-resolved X-ray diffraction throughout the volume of a sample opens up entirely new possibilities in areas such as material analysis, cancer diagnosis, and explosive detection, thus offering the potential to revolutionize the fields of medical, security, and industrial imaging and detection. Featuring chapters written by an international selection of authors from both academia and industry, the book provides a comprehensive discussion of the underlying physics, architectures, and applications of X-ray diffraction imaging that is accessible and relevant to neophytes and experts alike. Teaches novel methods for X-ray diffraction imaging Comprehensive and self-contained discussion of the relevant physics, imaging techniques, system components, and data processing algorithms Features state-of-the-art work of international authors from both academia and industry. Includes practical applications in the medical, industrial, and security sectors

Download or read book Radiation characteristics of extreme UV and soft X ray sources written by Tobias Mey and published by Göttingen University Press. This book was released on 2015 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electromagnetic radiation in the extreme UV and soft x-ray spectral range is of steadily increasing importance in fundamental research and industrial applications. An optimum use of the available photons can only be achieved under condition of a comprehensive beam characterization. Following that goal, this work addresses the pathway of extreme UV and soft x-ray radiation from its generation, through the beam transport by the beamline to the probe position. Experimentally, those aspects are optimized at a laser-produced plasma source and at an arrangement for the generation of high-harmonics. Additionally, the coherence of laser beams is analyzed by measurements of the Wigner distribution function. This method is applied to the photon beam of the free-electron laser FLASH, resulting in the entire characterization of its propagation properties.