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Das Verständnis der Katalysatordesaktivierung durch Verkokung ist entscheidend für ein wissensbasiertes Katalysator- und Prozessdesign bei Reaktionen mit Kohlenstoffverbindungen. Die Katalysatorverkokung wird dabei typischerweise durch Post-Mortem-Analyse untersucht. In der vorliegenden Arbeit wird ptychographische Röntgentomographie (PXCT) zur Analyse von künstlich verkokten Ni/Al2O3-Katalysatoren für die CO2-Methansierung und CH4-Trockenreformierung verwendet. PXCT liefert dabei 3D-Informationen der lokalen Elektronendichte mit ca. 80 nm Auflösung und ermöglicht somit die Visualisierung und Untersuchung der Ausprägung der Verkokung in Katalysatorpartikeln mit einem Durchmesser von ca. 40 μm. Die Verkokung wurde hauptsächlich im nanoporösen Festkörper identifiziert und konnte nicht in den aufgelösten Makroporen gefunden werden. Die Kohlenstoffbildung wurde unabhängig dazu mittels operando Raman-Spektroskopie bestätigt. PXCT wird als aufkommende Charakterisierungstechnik hervorgehoben, die eine nanoskalige Identifizierung, Lokalisierung und möglicherweise Quantifizierung von verschiedenen Desaktivierungsphänomenen mit 3D-Auflösung in kompletten Katalysatorpartikeln ermöglicht.

Studies of the structural and functional role of chromosomes in cytogenetics have spanned more than 10 decades. In this work, we take advantage of the coherent X-rays available at the latest synchrotron sources to extract the individual masses of all 46 chromosomes of metaphase human B and T cells using hard X-ray ptychography. We have produced ‘X-ray karyotypes’ of both heavy metal–stained and unstained spreads to determine the gain or loss of genetic material upon low-level X-ray irradiation doses due to radiation damage. The experiments were performed at the I-13 beamline, Diamond Light Source, Didcot, UK, using the phase-sensitive X-ray ptychography method.

Due to complex degradation mechanisms, disparities between the theoretical and practical capacities of lithium-ion battery cathode materials persist. Specifically, Ni-rich chemistries such as LiNi0.8Mn0.1Co0.1O2 (or NMC811) are one of the most promising choices for automotive applications; however, they continue to suffer severe degradation during operation that is poorly understood, thus challenging to mitigate. Here we use operando Bragg coherent diffraction imaging for 4D analysis of these mechanisms by inspecting the individual crystals within primary particles at various states of charge (SoC). Although some crystals were relatively homogeneous, we consistently observed non-uniform distributions of inter- and intracrystal strain at all measured SoC. Pristine structures may already possess heterogeneities capable of triggering crystal splitting and subsequently particle cracking. During low-voltage charging (2.7-3.5 V), crystal splitting may still occur even during minimal bulk deintercalation activity; and during discharging, rotational effects within parallel domains appear to be the precursor for the nucleation of screw dislocations at the crystal core. Ultimately, this discovery of the central role of crystal grain splitting in the charge/discharge dynamics may have ramifications across length scales that affect macroscopic performance loss during real-world battery operation.

Ptychography is a form of lens-free coherent diffractive imaging now used extensively in electron and synchrotron-based X-ray microscopy. In its near-field implementation, it offers a route to quantitative phase imaging at an accuracy and resolution competitive with holography, with the added advantages of extended field of view and blind deconvolution of the illumination beam profile from the sample image. In this paper we show how near-field ptychography can be combined with a multi-slice model, adding to this list of advantages the unique ability to recover high-resolution phase images of larger samples, whose thickness places them beyond the depth of field of alternative methods.

X-ray ptychography is a coherent scanning imaging technique widely used at synchrotron facilities for producing quantitative phase images beyond the resolution limit of conventional x-ray optics. The scanning nature of the technique introduces an inherent overhead to the collection at every scan position and limits the acquisition time of each 2D projection. The overhead associated with motion can be minimised with a continuous-scanning approach. Here we present an acquisition architecture based on continuous-scanning and up-triggering which allows to record ptychographic datasets at up to 9 kHz. We demonstrate the method by applying it to record 2D scans at up to 273 µm2/s and 3D scans of a (20 µm)3 volume in less than three hours. We discuss the current limitations and the outlook toward the development of sub-second 2D acquisition and minutes-long 3D ptychographic tomograms.

A possible improvement on a new method of single acquisition hyperspectral (spectroscopic) ptychographic imaging, making use of a hyperspectral X-ray camera, is presented. Undulator tapering is used at the synchrotron to broaden the energy distribution of the X-ray beam to a suitable level for edge subtraction. The combination of a coherent imaging method such as ptychography with spectroscopy poses difficulties in experimental setup design regarding probe size. The final goal of the experiment, a K-edge subtraction, is not successful, but the technique is nevertheless promising. The capability of resolving the absorption edge applies to a wide range of research areas, such as element specific investigations in biological, materials, and earth sciences. We discuss the problems and their possible solutions.

We report about our current capabilities and future plans in multi-scale imaging with high recording speed. For micro-tomographic imaging an automated system is used measuring up to 300 samples per day. For sub-micron and nano measurements the so-called polychromatic ‘pink beam’ is employed. The larger energy bandwidth compared to monochromatic beam permits recording times similar to microtomography. For highest resolution namely ptychography the acquisition time for tomographic scans is currently in the order of hours and below an hour in the near future. The current multi-scale science and the scientific perspective with the Diamond beamline I13L upgrade will be presented.

Here we report the results of multiple analytical techniques on sub-mm particulate material derived from Unit 1 of the Fukushima Daiichi Nuclear Power Plant to provide a better understanding of the events that occurred and the environmental legacy. Through combined x-ray fluorescence and absorption contrast micro-focused x-ray tomography, entrapped U particulate are observed to exist around the exterior circumference of the highly porous Si-based particle. Further synchrotron radiation analysis of a number of these entrapped particles shows them to exist as UO2—identical to reactor fuel, with confirmation of their nuclear origin shown via mass spectrometry analysis. While unlikely to represent an environmental or health hazard, such assertions would likely change should break-up of the Si-containing bulk particle occur. However, more important to the long-term decommissioning of the reactors at the FDNPP (and environmental clean-upon), is the knowledge that core integrity of reactor Unit 1 was compromised with nuclear material existing outside of the reactors primary containment., The larger particulates from reactor Unit 1 of the Fukushima Daiichi Nuclear Power Plant have received sparse attention compared to the Unit 2 particulate. Here the authors perform the higher-resolution and 3-dimentional analysis of several high-density micron-scale fragments, from within a larger Unit 1-derived representative ejecta particle.

X-ray ptychography has revolutionised nanoscale phase contrast imaging at large-scale synchrotron sources in recent years. We present here the first successful demonstration of the technique in a small-scale laboratory setting. We conducted an experiment with a liquid metal-jet X-ray source and a single photon-counting detector with a high spectral resolution. The experiment used a spot size of 5 microns to produce a ptychographic phase image of a Siemens star test pattern with a sub-micron spatial resolution. The result and methodology presented show how high-resolution phase contrast imaging can now be performed at small-scale laboratory sources worldwide., Comment: 14 pages, 4 figures

Studies of the structural and functional role of chromosomes in cytogenetics have spanned more than 10 decades. In this work, we take advantage of the coherent X-rays available at the latest synchrotron sources to extract the individual masses of all 46 chromosomes of metaphase human B and T cells using hard X-ray ptychography. We have produced 'X-ray karyotypes' of both heavy metal-stained and unstained spreads to determine the gain or loss of genetic material upon low-level X-ray irradiation doses due to radiation damage. The experiments were performed at the I-13 beamline, Diamond Light Source, Didcot, UK, using the phase-sensitive X-ray ptychography method.

A novel scheme for simultaneous X-ray ptychographic and fluorescence imaging is presented. The method is based on a dual energy X-ray beam, chromatic focusing optics and an energy discriminating photon counting detector., X-ray ptychography and X-ray fluorescence are complementary nanoscale imaging techniques, providing structural and elemental information, respectively. Both methods acquire data by scanning a localized beam across the sample. X-ray ptychography processes the transmission signal of a coherent illumination interacting with the sample, to produce images with a resolution finer than the illumination spot and step size. By enlarging both the spot and the step size, the technique can cover extended regions efficiently. X-ray fluorescence records the emitted spectra as the sample is scanned through the localized beam and its spatial resolution is limited by the spot and step size. The requisites for fast ptychography and high-resolution fluorescence appear incompatible. Here, a novel scheme that mitigates the difference in requirements is proposed. The method makes use of two probes of different sizes at the sample, generated by using two different energies for the probes and chromatic focusing optics. The different probe sizes allow to reduce the number of acquisition steps for the joint fluorescence–ptychography scan compared with a standard single beam scan, while imaging the same field of view. The new method is demonstrated experimentally using two undulator harmonics, a Fresnel zone plate and an energy discriminating photon counting detector.

Understanding catalyst deactivation by coking is crucial for knowledge‐based catalyst and process design in reactions with carbonaceous species. Post‐mortem analysis of catalyst coking is often performed by bulk characterization methods. Here, hard X‐ray ptychographic computed tomography (PXCT) was used to study Ni/Al2O3 catalysts for CO2 methanation and CH4 dry reforming after artificial coking treatment. PXCT generated quantitative 3D maps of local electron density at ca. 80 nm resolution, allowing to visualize and evaluate the severity of coking in entire catalyst particles of ca. 40 μm diameter. Coking was primarily revealed in the nanoporous solid, which was not detectable in resolved macropores. Coke formation was independently confirmed by operando Raman spectroscopy. PXCT is highlighted as an emerging characterization tool for nanoscale identification, co‐localization, and potentially quantification of deactivation phenomena in 3D space within entire catalyst particles., The formation of coke in nickel‐based catalyst particles can be investigated by ptychographic X‐ray computed tomography with sub‐100 nm resolution. Based on localized changes of electron density between the activated and coked catalysts, the location of coke can be resolved in 3D at the nanoscale. This approach can be used to study different catalyst deactivation pathways on multiple length scales from nm to μm.

The structural form and elemental distribution of material originating from different Fukushima Daiichi Nuclear Power Plant reactors (Units 1 and 3) is hereby examined to elucidate their contrasting release dynamics and the current in-reactor conditions to influence future decommissioning challenges. Complimentary computed X-ray absorption tomography and X-ray fluorescence data show that the two suites of Si-based material sourced from the different reactor Units have contrasting internal structure and compositional distribution. The known event and condition chronology correlate with the observed internal and external structures of the particulates examined, which suggest that Unit 1 ejecta material sustained a greater degree of melting than that likely derived from reactor Unit 3. In particular, we attribute the near-spherical shape of Unit 1 ejecta and their internal voids to there being sufficient time for surface tension to round these objects before the hot (and so relatively low viscosity) silicate melt cooled to form glass. In contrast, a more complex internal form associated with the sub-mm particulates invoked to originate from Unit 3 suggest a lower peak temperature, over a longer duration. Using volcanic analogues, we consider the structural form of this material and how it relates to its environmental particulate stability and the bulk removal of residual materials from the damaged reactors. We conclude that the brittle and angular Unit 3 particulate are more susceptible to further fragmentation and particulate generation hazard than the round, higher-strength, more homogenous Unit 1 material.

CO2 methanation is often performed on Ni/Al2O3 catalysts, which can suffer from mass transport limitations and, therefore, decreased efficiency. Here we show the application of a hierarchically porous Ni/Al2O3 catalyst for methanation of CO2. The material has a well-defined and connected meso- and macropore structure with a total porosity of 78%. The pore structure was thoroughly studied with conventional methods, i.e., N2 sorption, Hg porosimetry, and He pycnometry, and advanced imaging techniques, i.e., electron tomography and ptychographic X-ray computed tomography. Tomography can quantify the pore system in a manner that is not possible using conventional porosimetry. Macrokinetic simulations were performed based on the measures obtained by porosity analysis. These show the potential benefit of enhanced mass-transfer properties of the hierarchical pore system compared to a pure mesoporous catalyst at industrially relevant conditions. Besides the investigation of the pore system, the catalyst was studied by Rietveld refinement, diffuse reflectance ultraviolet-visible (DRUV/vis) spectroscopy, and H2-temperature programmed reduction (TPR), showing a high reduction temperature required for activation due to structural incorporation of Ni into the transition alumina. The reduced hierarchically porous Ni/Al2O3 catalyst is highly active in CO2 methanation, showing comparable conversion and selectivity for CH4 to an industrial reference catalyst.

In this work, ferroelastic domain walls inside ${\mathrm{BaTiO}}_{3}$ (BTO) tetragonal nanocrystals are distinguished by Bragg peak position and studied with Bragg coherent x-ray diffraction imaging (BCDI). Convergence-related features of the BCDI method for strongly phased objects are reported. A ferroelastic domain wall inside a BTO crystal has been tracked and imaged across the tetragonal-cubic phase transition and proves to be reversible. The linear relationship of relative displacement between two twin domains with temperature is measured and shows a different slope for heating and cooling, while the tetragonality reproduces well over temperature changes in both directions. An edge dislocation is also observed and found to annihilate when heating the crystal close to the phase transition temperature.

Both the three-dimensional internal structure and elemental distribution of near-field radioactive fallout particulate material released during the March 2011 accident at the Fukushima Daiichi Nuclear Power Plant is analysed using combined high-resolution laboratory and synchrotron radiation x-ray techniques. Results from this study allow for the proposition of the likely formation mechanism of the particles, as well as the potential risks associated with their existence in the environment, and the likely implications for future planned reactor decommissioning. A suite of particles is analyzed from a locality 2 km from the north-western perimeter of the site – north of the primary contaminant plume in an area formerly attributed to being contaminated by fallout from reactor Unit 1. The particles are shown to exhibit significant structural similarities; being amorphous with a textured exterior, and containing inclusions of contrasting compositions, as well as an extensive internal void volume – bimodal in its size distribution. A heterogeneous distribution of the various elemental constituents is observed inside a representative particle, which also exhibited a Fukushima-derived radiocesium (134Cs, 135Cs and 137Cs) signature with negligible natural Cs. We consider the structure and composition of the particle to suggest it formed from materials associated with the reactor Unit 1 building explosion, with debris fragments embedded into the particles surface. Such a high void ratio, comparable to geological pumice, suggests such material formed during a rapid depressurisation and is potentially susceptible to fragmentation through attrition.

We present here a new method of performing X-ray edge-subtraction ptychographic imaging by combining multiple harmonics from an undulator synchtrotron source and an energy discriminating photon counting detector. Conventionally, monochromatic far-field X-ray ptychography is used to perform edge subtraction through the use of multiple monochromatic energy scans to obtain spectral information for a variety of applications. Here, we use directly the undulator spectrum from a synchrotron source, selecting two separate harmonics post sample using the Pixirad-1/Pixie-III detector. The result is two monochromatic images, above and below an absorption edge of interest. The proposed method is applied to obtain Au L-edge subtraction imaging of a Au-Ni grid test sample. The Au L-edge subtraction is particularly relevant for the identification of gold nanoparticles for biomedical applications. Switching the energy scan mechanism from a mechanical monochromator to an electronic detector threshold allows for faster spectral data collection with improved stability.

The Diamond Beamline I13L is dedicated to micro- and nano- imaging, with two independently operating branchlines. The imaging branch preforms imaging in real space, with In-line phase contrast imaging and grating interferometry at micrometre resolution and full-field transmission microscopy up to 50nm spatial resolution. Highest spatial resolution is achieved on the coherence branchline, where diffraction imaging methods such as Ptychography and Bragg-CDI are performed. The article provides an update about the experimental capabilities at the beamline with an emphasis on the rapidly evolving ptychography capabilities. The latter has evolved to an user-friendly method with non-expert users able to explore their science without any specific a-priory knowledge.

The DIAMOND beamline I13L is dedicated to multi-scale and multi-modal imaging in real and reciprocal space. The beamline consists of two independently operating experimental stations, located at a distance of more than 200 m from the source. The Imaging Branch performs micro-tomography with in-line phase contrast in the 6-30 keV energy range. In addition, a grating interferometry setup and a full-field microscope for nano-tomography are currently implemented. Other techniques providing high-resolution three-dimensional information, in particular coherent X-ray diffraction, are hosted on the Coherence Branch. All imaging methods are tested to operate with large energy bandwidths and therefore shorter exposure times. To this end, two options are currently used: the so-called 'pink-beam' mode using a reflecting mirror and X-ray filters and monochromatic mode using a multilayer monochromator. The operation mode enables science for in-situ and operando studies across a wide range of scientific areas.

We present a new method of single acquisition spectroscopic imaging with high spatial resolution. The technique is based on the combination of polychromatic synchrotron radiation and ptychographic imaging with a recently developed energy discriminating detector. We demonstrate the feasibility with a Ni-Cu test sample recorded at I13-1 of the Diamond Light Source, UK. The two elements can be clearly distinguished and the Ni absorption edge is identified. The results prove the feasibility of obtaining high-resolution structural and chemical images within a single acquisition using a polychromatic X-ray beam. The capability of resolving the absorption edge applies to a wide range of research areas, such as magnetic domains imaging and element specific investigations in biological, materials, and earth sciences. The method utilises the full available radiation spectrum and is therefore well suited for broadband radiation sources.

The nature of the atomic structure of many non-crystalline materials remains a long-standing open question. We use X-ray scattering to model electron images of amorphous materials, where the analogue 'atoms' consist of 1 μm diameter glass beads. The beads form a substantially random close-packed structure, but are partially ordered in places. X-ray ptycho-tomography reveals the exact position of the beads in 3D and so can be used to compare the modelled electron image with full knowledge of the underlying real structure. Using this, we repeat an experiment reported by Archie Howie and colleagues in 1978 that sought to test for real structure in bright-field electron images of amorphous materials; we demonstrate the validity of the technique, at least in the case of the resolution of the microscopes available at that time and the first Born approximation. We also illustrate how extremely demanding it would have been to infer 3D structure of amorphous material from pairs of stereoscopic images obtained with the same experimental kit: an approach that Archie proposed in the 1970s. We briefly discuss the possibility of using electron ptycho-tomography to solve the amorphous structure problem.

Ptychographic X-ray computed tomography is a phase-contrast imaging technique capable of retrieving three-dimensional maps of the index of refraction of the imaged volumes with nanometric resolution. Despite its unmatched reach, its application remains prerogative of a limited number of laboratories at synchrotron sources. We present a detailed description of an experimental procedure and a data analysis pipeline which can be both exploited for ptychographic X-ray computed tomography experiments at any high-brilliance X-ray source. These have been validated at the I13-1 Coherence Branchline within the first experiment of its kind to be successfully carried out on a biological sample at Diamond Light Source.

Optics letters 44(18), 4622 - 4625 (2019). doi:10.1364/OL.44.004622, In this Letter, we report on the creation of hard x-ray beams carrying orbital angular momentum of topological charge $−ℏ$ and $−3ℏ$ at a photon energy of 8.2 keV via spiral phase plates made out of fused silica by ultrashort-pulsed laser ablation. The phase plates feature a smooth phase ramp with a 0.5 μm nominal step height and a surface roughness of 0.5 μm. The measured vortex beams show submicrometer-sized donut rings and agree well with numerical modeling. Fused silica phase plates are potentially suited to manipulate the electromagnetic field in highly intense x-ray beams at x-ray free-electron laser sources., Published by OSA, Washington, DC

The I13 imaging and coherence beamline aims for multiscale imaging in the energy range of 6-30keV. The achievable resolution ranges from several microns to tens of nanometers. Several experimental methods are available on two independently operating branchlines. The Diamond-Manchester imaging branchline applies methods in direct space, such as In-line phase contrast, grating interferometry and full-field microscopy. The coherence branch covers far-field techniques such as ptychography and Bragg-CDI. The ptychography is now available as user-friendly experiment and the spatial and temporal resolution has been significantly enhanced. The scientific program at I13 will increasingly explore the suite of experimental techniques available at the beamline for multi-scale imaging.

The Coherence branch of the I13 beamline in Diamond Light Source is specialized in reciprocal space imaging using Ptychography and Bragg CDT techniques. The experimental hutch is 220 m from the synchrotron source, providing the x-ray beam with intrinsic high spatial coherence. The capacious hutch allows variable sample-detector distance up to l4.5 m. This, in combination with the use of the large area photon counting detector Excalibur, enables fields of view as large as 500 μm, resolution down to tens of nanometers and acquisition rate in excess of l00 Hz. Recently the ptychography scan has been combined to the x-ray fluorescence scan to simultaneously access the chemical and structural information of the sample.

Preserving the coherence and wavefront of a diffraction limited x-ray beam from the source to the experiment poses stringent quality requirements on the production processes for X-ray optics. In the near future this will require on-line and in-situ at-wavelength metrology for both, free electron lasers and diffraction limited storage rings. A compact and easy to move X-ray grating interferometry (XGI) setup has been implemented by the Beamline Optics Group at PSI in order to characterize x-ray optical components by determining the aberrations from reconstructing the x-ray wavefront. The XGI setup was configured for measurements in the moire mode and tested with focusing optic at Swiss Light Source, Diamond Light Source and LCLS. In this paper measurements on a bendable toroidal mirror, a zone plate, a single and a stack of beryllium compound refractive lenses (CRL) are presented. From these measurements the focal position and quality of the beam spot in terms of wavefront distortions are determined by analysing the phase-signal obtained from the XGI measurement. In addition, using a bendable toroidal mirror, we directly compare radius of curvature measurements obtained from XGI data with data from a long-trace profilometer, and compare the CRL wavefront distortions with data obtained by ptychography.

The Diamond I13 imaging and coherence beamline performs multiscale imaging and tomography with phase sensitive imaging methods. Operating in the energy range of 6-30keV, the achievable resolution ranges from several microns to tens of nanometers [1,2]. The beamline is unique in combining imaging methods in real and reciprocal spaces, which are available on two independently operating branchlines. The scientific program is currently being developed with the distinct capabilities offered by the beamline. Most recently ptycho-tomography has become operational and a multitude of scientific projects is linking the research between both branchlines. The Diamond-Manchester imaging branchline performs mainly in-line phase contrast microtomography with a strong emphasis on dedicated sample environments. Failure of lithium batteries, material cracks, structure of ice cream, bones under load, and storage of CO2 in brine and sandstone are some examples studied under realistic conditions. Most experiments are carried out in the so-called polychromatic 'pink-beam' mode, with micron resolution and millisecond exposure times. Furthermore, a multilayer and a Si (111) monochromator are available for element selective measurements. Two additional projects (full-field microscope and grating interferometry) are currently under development for studies with submicron resolution and phase sensitive imaging. The full-field microscope can perform Zernike phase contrast imaging over a field of view of 50-100µm with a resolution of 50-100nm. The large working distance over several centimeters enable a large variety of scientific applications with dedicated sample environments [3,4]. The different stripes of the multilayer monochromator provide a bandwidth between E/E=10-3 and 10-2 and combined with a fibre-optic plate coupled sCMOS detector, exposure times of few 100ms are achieved. Grating interferometry provides superb image quality, measuring the absolute phase and providing small angle information. We currently plan to apply this method to identify nano-sized structures with micrometer resolution [5,6], as for example in the studies on bones, battery materials, pharmaceutical products or industrial filter materials. Highest spatial resolution is achieved on the coherence branch with ptychographic imaging with 30nm spatial resolution. The photon counting EXCALIBUR detector can continuously record with a speed of up to 250Hz over an array of 1.5x2kPixels. After the last year of development the recording speed for ptycho-tomography scan has significantly improved. A full scan currently takes a few hours and is anticipated to be further accelerated. Ptychography is now performed as standard user experiment, enabling the beamline's ambition for multi-scale imaging. A large number of pilot experiments are being

A detailed description of an imaging protocol which integrates both near- and far-field ptychography with full-field and scanning transmission X-ray microscopy in multiscale imaging experiments at synchrotron endstations is given., The success of ptychography and other imaging experiments at third-generation X-ray sources is apparent from their increasingly widespread application and the improving quality of the images they produce both for resolution and contrast and in terms of relaxation of experimental constraints. The wider availability of highly coherent X-rays stimulates the development of several complementary techniques which have seen limited mutual integration in recent years. This paper presents a framework in which some of the established imaging techniques – with particular regard for ptychography – are flexibly applied to tackle the variable requirements occurring at typical synchrotron experiments. In such a framework one can obtain low-resolution images of whole samples and smoothly zoom in on specific regions of interest as they are revealed by switching to a higher-resolution imaging mode. The techniques involved range from full-field microscopy, to reach the widest fields of view (>mm), to ptychography, to achieve the highest resolution (

The Diamond Beamline I13L is dedicated to imaging on the micro- and nano-lengthsale, operating in the energy range between 6 and 30keV. For this purpose two independently operating branchlines and endstations have been built. The imaging branch is fully operational for micro-tomography and in-line phase contrast imaging with micrometre resolution. Grating interferometry is currently implemented, adding the capability of measuring phase and small-angle information. For tomography with increased resolution a full-field microscope providing 50nm spatial resolution with a field of view of 100μm is being tested. The instrument provides a large working distance between optics and sample to adapt a wide range of customised sample environments. On the coherence branch coherent diffraction imaging techniques such as ptychography, coherent X-ray diffraction (CXRD) are currently developed for three dimensional imaging with the highest resolution. The imaging branch is operated in collaboration with Manchester University, called therefore the Diamond-Manchester Branchline. The scientific applications cover a large area including bio-medicine, materials science, chemistry geology and more. The present paper provides an overview about the current status of the beamline and the science addressed.

The Diamond Beamline I13L is designed to imaging on the micron- and nano-lengthsale with X-rays of energies between 6 and 30 keV [1]. Two independently operating branchlines and endstations have been built at distance of more than 200m from the source for this purpose. The imaging branch is dedicated for imaging in real space, providing In-line phase contrast imaging and grating interferometry with micrometre resolution and full-field transmission microscopy with 50nm spatial resolution. On the coherence branch coherent diffraction imaging techniques such as ptychography, coherent X-ray diffraction (CXRD) and Fourier-Transform holography are currently developed. Because of the large lateral coherence length available at I13, the beamline hosts numerous microscopy experiments. The coherence branchline in particular contains a number of unique features. New instrumental designs have been employed such as a robot arm for the detector in diffraction experiments and a photon counting detector for diffraction experiments. The so-called ‘mini-beta’ layout in the straight section of the electron storage ring permits modulating the horizontal source size and therefor the lateral coherence length. We will present the recent progress in coherent imaging at the beamline and the sciences addressed with the instrumental capabilities. Reference: [1] C. Rau, U. Wagner, Z. Pesic, A. De Fanis Physica Status Solidi (a) 208 (11). Issue 11 2522-2525, 2011, 10.1002/pssa.201184272

We investigate a strategy for separating the influence of three-dimensional scattering effects in tilt-series reconstruction, a method for computationally increasing the resolution of a transmission microscope with an objective lens of small numerical aperture, as occurs in the transmission electron microscope (TEM). Recent work with visible light refers to the method as Fourier ptychography. To date, reconstruction methods presume that the object is thin enough so that the beam tilt induces only a shift of the diffraction pattern in the back focal plane. In fact, it is well known that the diffraction pattern changes as a function of beam tilt when the object is thick. In this paper, we use a simple visible light model to demonstrate a proof-of-principle of a new reconstruction algorithm that can cope with this difficulty and compare it with the aperture-scanning method. Although the experiment uses a model specimen with just two distinct layers separated along the optic axis, it should in principle be extendable to continuous objects.

We retrieve x-ray phase images from ptychographical data which, according to the conventional coherent diffractive imaging (CDI) criterion, have been grossly undersampled. Ptychographical data are intrinsically oversampled in real space, as the illumination function of subsequent exposures overlap. By exploiting the real-space redundancy in ptychography, we are able to recover the conventional CDI reciprocal sampling, despite an increase in the solid angle of the detector pixels. As a result the current experimental geometrical constraints placed upon probe size, object to detector distance, and pixel size are all relaxed.

We show for the first time that ptychography (a form of lensless diffractive imaging) can recover the spectral response of an object through simultaneous reconstruction of multiple images that represent the object's response to a particular mode present in the illumination. We solve the phase problem for each mode independently, even though the intensity arriving at every detector pixel is an incoherent superposition of several uncorrelated diffracted waves. Until recently, the addition of incoherent modes has been seen as a nuisance in diffractive imaging: here we show that not only can the difficulties they pose be removed, but that they can also be used to discover much more information about the object. If the illumination function is also mode-specific, we show that we can also solve simultaneously for a multiplicity of such illumination modes. The work opens exciting possibilities for information multiplexing in ptychography over all visible, X-ray and electron wavelengths.

We employ a novel combination of a Fresnel lens and a diffuser for x-ray ptychography. The setup uses increased flux by enlarging the width of the coherence-defining slits upstream of the experimental station. In the reconstruction algorithm, modal decomposition is used to account for the resulting partial coherence in the beam. We show that if the object has sparse feactures and large areas of flat contrast, the diffuser facilitates a better reconstruction and the extra diversity in the data also allows cleaner separation of the constituent modes in the illumination. The setup also allows a quick, real-time measure of the beam coherence.

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.