This PDF file contains the front matter associated with SPIE Proceedings Volume 8851 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

Hard X-ray fluorescence microscopy is one of the most sensitive techniques to perform trace elemental analysis of unsectioned biological samples, such as cells and tissues. As the spatial resolution increases beyond sub-micron scale, conventional sample preparation method, which involves dehydration, may not be sufficient for preserving subcellular structures in the context of radiation-induced artifacts. Imaging of frozen-hydrated samples under cryogenic conditions is the only reliable way to fully preserve the three dimensional structures of the samples while minimizing the loss of diffusible ions. To allow imaging under this hydrated “natural-state” condition, we have developed the Bionanoprobe (BNP), a hard X-ray fluorescence nanoprobe with cryogenic capabilities, dedicated to studying trace elements in frozen-hydrated biological systems. The BNP is installed at an undulator beamline at Life Sciences Collaboration Access Team at the Advanced Photon Source. It provides a spatial resolution of 30 nm for fluorescence imaging by using Fresnel zone plates as nanofocusing optics. Differential phase contrast imaging is carried out in parallel to fluorescence imaging by using a quadrant photodiode mounted downstream of the sample. By employing a liquid-nitrogen-cooled sample stage and cryo specimen transfer mechanism, the samples are well maintained below 110 K during both transfer and X-ray imaging. The BNP is capable for automated tomographic dataset collection, which enables visualization of internal structures and composition of samples in a nondestructive manner. In this presentation, we will describe the instrument design principles, quantify instrument performance, and report the early results that were obtained from frozen-hydrated whole cells.

The Nanoscopium 155 m-long scanning nanoprobe beamline of Synchrotron Soleil (St Aubin, France) is dedicated to quantitative multi-modal imaging. Dedicated experimental stations, working in consecutive operation mode, will provide coherent scatter imaging and spectro-microscopy techniques in the 5-20 keV energy range for various user communities. Next to fast scanning, cryogenic cooling will reduce the radiation damage of sensitive samples during the measurements. Nanoscopium is in the construction phase, the first user experiments are expected in 2014. The main characteristics of the beamline and an overview of its status are given in this contribution.

The Advanced Photon Source is currently developing a suite of new hard x-ray beamlines, aimed primarily at the study of materials and devices under real conditions. One of the flagship beamlines of the APS Upgrade is the In-Situ Nanoprobe beamline (ISN beamline), which will provide in-situ and operando characterization of advanced energy materials and devices under change of temperature and gases, under applied fields, in 3D. The ISN beamline is designed to deliver spatially coherent x-rays with photon energies between 4 keV and 30 keV to the ISN instrument. As an x-ray source, a revolver-type undulator with two interchangeable magnetic structures, optimized to provide high brilliance throughout the range of photon energies of 4 keV – 30 keV, will be used. The ISN instrument will provide a smallest hard x-ray spot of 20 nm using diffractive optics, with sensitivity to sub-10 nm sample structures using coherent diffraction. Using nanofocusing mirrors in Kirkpatrick-Baez geometry, the ISN will also provide a focus of 50 nm with a flux of 8·10¹¹ Photons/s at a photon energy of 10 keV, several orders of magnitude larger than what is currently available. This will allow imaging of trace amounts of most elements in the periodic table, with a sensitivity to well below 100 atoms for most metals in thin samples. It will also enable nanospectroscopic studies of the chemical state of most materials relevant to energy science. The ISN beamline will be primarily used to study inorganic and organic photovoltaic systems, advanced batteries and fuel cells, nanoelectronics devices, and materials and systems diesigned to reduce the environmental impact of combustion.

Compact advanced Kirkpatrick–Baez optics are used to construct a microscope that is easy to align and robust against vibrations and thermal drifts. The entire length of the imaging mirror system is 286 mm, which is 34% shorter than the previous model. A spatial resolution test is performed in which magnified bright-field images of a pattern are taken with an X-ray camera at an energy of 10 keV at the BL29XUL beamline of SPring-8. A line-and-space pattern having a 50- nm width could be resolved, although the image contrast is low.

A hard x-ray imaging microscope system of high spatial resolution and large field of view (FOV) has been developed at the beamline 37 XU of SPring-8. By utilizing the 30 m-long experimental station, large magnification can be attained with a large diameter Fresnel zone plate (FZP) objective. Some configurations of microscope systems were tested. In a typical condition, a magnification of 133 and a FOV of 123 μm are attained using a FZP with a diameter of 310 μm and an outermost zone width of 100 nm, and the spatial resolution evaluated by observing resolution test chart is 160 nm in full pitch of periodic object with an exposure time of 1 s. When a FZP with an outermost zone width of 50 nm is used, a spatial resolution better than 100 nm is achieved. Phase-contrast imaging by Zernike’s method was also tested, and three dimensional measurement by computer tomography (CT) method was also carried out.

Combining the energy tunability provided by synchrotron X-ray sources with transmission X-ray microscopy, the morphology of materials can be resolved in 3D at spatial resolution down to 30 nm with elemental/chemical specification. In order to study the energy dependence of the absorption coefficient over the investigated volume, the tomographic reconstruction and image registration (before and/or after the tomographic reconstruction) are critical. We show in this paper the comparison of two different data processing strategies and conclude that the signal to noise ratio (S/N) in the final result can be improved via performing tomographic reconstruction prior to the evaluation of energy dependence. Our result echoes the dose fractionation theorem, and is particularly helpful when the element of interest has low concentration.

Radiation damage is a topic typically sidestepped in formal discussions of characterization techniques utilizing ionizing radiation. Nevertheless, such damage is critical to consider when planning and performing experiments requiring large radiation doses or radiation sensitive samples. High resolution, in situ transmission X-ray microscopy of Li-ion batteries involves both large X-ray doses and radiation sensitive samples. To successfully identify changes over time solely due to an applied current, the effects of radiation damage must be identified and avoided. Although radiation damage is often significantly sample and instrument dependent, the general procedure to identify and minimize damage is transferable. Here we outline our method of determining and managing the radiation damage observed in lithium sulfur batteries during in situ X-ray imaging on the transmission X-ray microscope at Stanford Synchrotron Radiation Lightsource.

This paper presents the advance in spectroscopic imaging technique and analysis method from the newly developed transmission x-ray microscopy (TXM) at the beamline X8C of National Synchrotron Light Source. Through leastsquares linear combination fitting we developed on the in situ spectroscopic images, a time-dependent and spatially resolved chemical composition mapping can be obtained and quantitatively analyzed undergone chemical/electrochemical reactions. A correlation of morphological evolution, chemical state distribution changes and reaction conditions can be revealed. We successfully applied this method to study the electrochemical evolution of CuO, an anode material of Li-ion battery, during the lithiation-delitiation cycling.

Full field transmission x-ray microscopy (TXM) is a newly developed x-ray imaging technique to provide quantitative and non-destructive 3D characterization of the complex microstructure of materials at nanometer resolution. A key missing component is an in situ apparatus enabling the imaging of the complex structural evolution of the materials and to correlate the structural change with a material’s functionality under real operating conditions. This work describes the design of an environmental cell which satisfies the requirements for in situ TXM studies. The limited space within the TXM presents a spatial constraint which prohibits the use of conventional heaters, as well as requiring consideration in designing for safe and controlled operation of the system and alignment of the cell with the beam. A gravity drip-fed water cooling jacket was installed in place around the heating module to maintain critical components of the microscope at safe operating temperatures. A motion control system consisting of pulse width modulated DC motor driven XYZ translation stages was developed to facilitate fine alignment of the cell. Temperature of the sample can be controlled remotely and accurately through a controller to temperatures as high as 1200 K. Heating zone measurement was carried out and shows a 500 x 500 x 500 μm3 homogeneous zone volume for sample area, which is a critical parameter to ensure accurate observation of structural evolution at nanometer scale with a sample in size of tens of microns. Application on Ni particles for in situ oxidation experiment and dehydrogenation of aluminum hydride is also discussed.

The design and implementation of a pair of 100 mm-long grazing-incidence total-reflection mirrors for the hard X-ray beamline Nanoscopium at Synchrotron Soleil is presented. A vertically and horizontally nanofocusing mirror pair, oriented in Kirkpatrick-Baez geometry, has been designed and fabricated with the aim of creating a diffraction-limited high-intensity 5 − 20 keV beam with a focal spot size as small as 50 nm. We describe the design considerations, including wave-optical calculations of figures-of-merit that are relevant for spectromicroscopy, such as the focal spot size, depth of field and integrated intensity. The mechanical positioning tolerance in the pitch angle that is required to avoid introducing high-intensity features in the neighborhood of the focal spot is demonstrated with simulations to be of the order of microradians, becoming tighter for shorter focal lengths and therefore directly affecting all nanoprobe mirror systems. Metrology results for the completed mirrors are presented, showing that better than 1.5 °A-rms figure error has been achieved over the full mirror lengths with respect to the designed elliptical surfaces, with less than 60 nrad-rms slope errors.

Beamline P11 at PETRA III is dedicated to structural investigations of biological samples. It provides two experimental stations, one for macromolecular crystallography and one for X-ray microscopy. The microscope will provide full field Zernike phase contrast and scanning microscopy both in 2D and in tomographic mode. Full field microscopy with a field of view of 50 x 50 μm² will allow to generate an overview of the sample and to select regions of interest for later inspection of the element distribution by X-ray fluorescence and diffraction in scanning mode. Central part of the microscope is an inhouse developed flexure based x,y,z scanner on top of a rotation stage. The scanner is operated in closed loop with piezo motors, has a travel range of 4 mm in horizontal and of 3 mm in vertical direction. With laser interferometers for closed loop operation a positioning accuracy of better than 5 nm is achieved in all directions. For precise sample rotation an in-vacuum air-bearing has been developed. An open bore in the center of the air-bearing allows cryogenic sample cooling by a cold He or N₂ gas stream. Different optical elements such as beam defining pinholes, a condensor, zone plates, OSA, phase rings, etc. can be centered in the beam path by piezomotor driven x,y flexure elements mounted on a rail system which allows further positioning along the beam path. Different 2D detectors and two fluoresence detectors can be attached to the microscope.

We describe the design of the NanoMAX beamline to be built among the first phase beamlines of the MAX IV facility in Lund, Sweden. NanoMAX will be a hard X-ray imaging beamline providing down to 10 nm in direct spatial resolution, enabling investigations of very small heterogeneous samples exploring methods of diffraction, scattering, absorption, phase contrast and fluorescence. The beamline will have two experimental stations using Fresnel zone plates and Kirkpatrick-Baez mirror optics for beam focusing, respectively. This paper focuses on the optical design of the beamline excluding the experimental stations but also describes general ideas about the endstations and the nano-focusing optics to be used. The NanoMAX beamline is planned to be operational late 2016.

Aiming at studies of the micro/nano-structures of a broad range materials and electronic devices, Advance Photon Source (APS) is developing a dedicated diffraction nanoprobe (DNP) beamline for the needs arising from a multidiscipline research community. As a part of the APS Upgrade Project, the planed facility, named Sub-micron 3-D Diffraction (S3DD) beamline¹, integrates the K-B mirror based polychromatic Laue diffraction and the Fresnel zone-plate based monochromatic diffraction techniques that currently support 3D/2D microdiffraction programs at the 34-ID-E and 2-ID-D of the APS, respectively. Both diffraction nanoprobes are designed to have a 50-nm or better special resolution. The zone-plate based monochromatic DNP has been preliminarily designed and will be constructed at the sector 34-ID. It uses an APS-3.0-cm period or APS-3.3-cm period undulator, a liquid-nitrogen cooled mirror as its first optics, and a water cooled small gap silicon double-crystal monochromator with an energy range of 5-30 keV. A set of zone plates have been designed to optimize for focusing efficiency and the working distance based on the attainable beamline length and the beam coherence. To ensure the nanoprobe performance, high stiffness and high precision flexure stage systems have been designed or demonstrated for optics mounting and sample scanning, and high precision temperature control of the experimental station will be implemented to reduce thermal instability. Designed nanoprobe beamline has a good management on thermal power loading on optical components and allows high degree of the preservation of beam brilliance for high focal flux and coherence. Integrated with variety of X-ray techniques, planed facility provides nano-XRD capability with the maximum reciprocal space accessibility and allows micro/nano-spectroscopy studies with K-edge electron binding energies of most elements down to Vanadium in the periodic table. We will discuss the preliminary design of the zone-plate based monochromatic DNP and its technical relevance to a broad range of scientific applications.

Scanning hard X-ray nanoprobe imaging provides a unique tool for probing specimens with high sensitivity and large penetration depth. Moreover, the combination of complementary techniques such as X-ray fluorescence, absorption, phase contrast and dark field imaging gives complete quantitative information on the sample structure, composition and chemistry. The multi-technique “FLYSCAN” data acquisition scheme developed at Synchrotron SOLEIL permits to perform fast continuous scanning imaging and as such makes scanning tomography techniques feasible in a time-frame well-adapted to typical user experiments. Here we present the recent results of simultaneous fast scanning multi-technique tomography performed at Soleil. This fast scanning scheme will be implemented at the Nanoscopium beamline for large field of view 2D and 3D multimodal imaging.

X-ray fluorescence images acquired using the Maia large solid-angle detector array and integrated real-time processor on the X-ray Fluorescence Microscopy (XFM) beamline at the Australian Synchrotron capture fine detail in complex natural samples with images beyond 100M pixels. Quantitative methods permit real-time display of deconvoluted element images and for the acquisition of large area XFM images and 3D datasets for fluorescence tomography and chemical state (XANES) imaging. This paper outlines the Maia system and analytical methods and describes the use of the large detector array, with a wide range of X-ray take-off angles, to provide sensitivity to the depth of features, which is used to provide an imaging depth contrast and to determine the depth of rare precious metal particles in complex geological samples.

The requirements on the spatial and temporal coherence for conventional Coherent Diffractive Imaging (CDI) have been well-established in the literature based on Shannon sampling of the diffracted intensities. The spatial coherence length of the illumination must be larger than twice the lateral dimensions of the sample whilst the temporal coherence length must be larger than the maximum optical path length difference between the two edges of the sample for the highest order diffraction peaks. However, recent approaches to CDI which have included knowledge of the spatial and temporal coherence information in the image reconstruction have allowed us to relax these conventional coherence constraints, extending the applicability of the technique to less coherent sources. In light of these developments it is useful to revisit the idea of a coherence limit in partially coherent CDI and establish a ‘universal’ limit on the partial coherence that can be tolerated without any loss of information. In this paper we present a simple and straightforward description of the limit of spatial and temporal coherence in partially coherent CDI.

It is now widely recognized that the intensity and brightness of inverse-Compton x-ray light sources can be enhanced through the use of a high finesse optical storage cavity. But the criteria for the practical use and optimization of such cavities are less well understood. We will review those criteria and their application to the development of an optimized high brightness 5 - 20 keV inverse-Compton x-ray source under development at the University of Hawai`i.

Recent breakthroughs in high harmonic generation have extended the reach of bright tabletop coherent light sources from a previous limit of ≈100 eV in the extreme ultraviolet (EUV) all the way beyond 1 keV in the soft X-ray region. Due to its intrinsically short pulse duration and spatial coherence, this light source can be used to probe the fastest physical processes at the femtosecond timescale, with nanometer-scale spatial resolution using a technique called coherent diffractive imaging (CDI). CDI is an aberration-free technique that replaces image-forming optics with a computer phase retrieval algorithm, which recovers the phase of a measured diffraction amplitude. This technique typically requires the sample of interest to be isolated; however, it is possible to loosen this constraint by imposing isolation on the illumination. Here we extend previous tabletop results, in which we demonstrated the ability to image a test object with 22 nm resolution using 13 nm light [3], to imaging of more complex samples using the keyhole CDI technique adapted to our source. We have recently demonstrated the ability to image extended objects in a transmission geometry with ≈100 nm resolution. Finally, we have taken preliminary CDI measurements of extended nanosystems in reflection geometry. We expect that this capability will soon allow us to image dynamic processes in nanosystems at the femtosecond and nanometer scale.

The focusing efficiency of binary Fresnel zone plate lenses is fundamentally limited and higher efficiency requires a multi step lens profile. To overcome the manufacturing problems of high resolution and high efficiency multistep zone plates, we investigate the concept of stacking two different binary zone plates in each other’s optical near-field. We use a coarse zone plate with π phase shift and a double density fine zone plate with π/2 phase shift to produce an effective 4- step profile. Using a compact experimental setup with piezo actuators for alignment, we demonstrated 47.1% focusing efficiency at 6.5 keV using a pair of 500 μm diameter and 200 nm smallest zone width. Furthermore, we present a spatially resolved characterization method using multiple diffraction orders to identify manufacturing errors, alignment errors and pattern distortions and their effect on diffraction efficiency.

Composites of La_0.4Sr_0.6Co_0.8Fe_0.2O_3−d (LSCF) with samarium doped ceria (SDC) have been extensively used as cathodes for solid oxide fuel cells (SOFCs) to lower its operation temperature. The ability to visualize three-dimensional (3D) microstructural changes in LSCF-SDC composite cathodes can help elucidate the impact of microstructure on cathode performance. This study reports that we utilize the nano-computed tomography (nano-CT) technique to image the 3D microstructures of La_0.4Sr_0.6Co_0.2Fe_0.8O₃ (LSCF) - Ce_0.8Sm_0.2O_1.9 (SDC) composite cathodes which were sintering at 800, 1000, and 1200°C, respectively, for 2 h based on the Fe K-absorption edge. Using the reconstructions of LSFC-SDC composite cathodes submitted to different temperatures, the key microstructural properties, such as volume fraction of each phase, connected volume fraction, surface area, triple-phase boundary length, and pore size were measured. The effect of sintering temperature on the microstructure of LSFC-SDC cathodes was discussed and compared with theoretical simulation. With increasing sintering temperature in the range from 800 to 1200°C LSFC-SDC composite cathode microstructure was found that the volume fraction and grain size of LSCF material increased, while the volume fraction of SDC decreased. Furthermore, the triple-phase boundary length per volume increased as the sintering temperature increasing. This study had revealed that the nano-CT can provide a powerful tool to investigate the 3D microstructure of energy materials and optimize its preparation condition to gain better functional performance.

Nano-CT has been considered as an important technique applied in analyzing inter-structures of nanomaterials and biological cell. However, maximum rotation angle of the sample stage is limited by sample space; meanwhile, the scan time is exorbitantly large to get enough projections in some cases. Therefore, it is difficult to acquire nano-CT images with high quality by using conventional Fourier reconstruction methods based on limited-angle or few-view projections. In this paper, we utilized the total variation (TV) iterative reconstruction to carry out numerical image and nano-CT image reconstruction with limited-angle and few-view data. The results indicated that better quality images had been achieved.

Soft X-ray nanotomography using ptychography allows quantitative imaging of the internal structure of biological and materials samples with high sensitivity. In this work, we describe progress toward the implementation of an interferometer-controlled microscope located at a beamline that provides coherent ux over the photon energy range of 200 to 2000 eV. Recent experimental results are presented to illustrate the potential for two- and three-dimensional imaging at the nanoscale.

Developments and advances in the e-beam lithography (EBL) made it possible to reach resolutions in a single digit nanometer range in the soft x-ray microscopy using Fresnel Zone Plates (FZP). However, it is very difficult to fabricate efficient FZPs for hard x-rays via this conventional fabrication technique due to limitations in the achievable aspect ratios. Here, we demonstrate the use of alternative fabrication techniques that depend on utilization of atomic layer deposition and focused ion beam processing to deliver FZPs that are efficient for the hard X-ray range.

Full field X-ray nano-imaging focusing on material science is under developing at SSRF. A dedicated full field X-ray nano-imaging beamline based on bending magnet will be built in the SSRF phase-II project. The beamline aims at the 3D imaging of the nano-scale inner structures. The photon energy range is of 5-14keV. The design goals with the field of view (FOV) of 20μm and a spatial resolution of 20nm are proposed at 8 keV, taking a Fresnel zone plate (FZP) with outermost zone width of 25 nm. Futhermore, an X-ray nano-imaging microscope is under developing at the SSRF BL13W beamline, in which a larger FOV will be emphasized. This microscope is based on a beam shaper and a zone plate using both absorption contrast and Zernike phase contrast, with the optimized energy set to 10keV. The detailed design and the progress of the project will be introduced.