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Shearing P.R.,Imperial College London | Gelb J.,Xradia Inc. | Brandon N.P.,Imperial College London
Journal of the European Ceramic Society | Year: 2010

High-resolution tomography techniques have facilitated an improved understanding of solid oxide fuel cell (SOFC) electrode microstructures.The use of X-ray nano computerised tomography (nano-CT) imposes some geometrical constraints on the sample under investigation; in this paper, we present the development of an advanced preparation technique to optimise sample geometries for X-ray nano-CT, utilizing a focused ion beam (FIB) system to shape the sample according to the X-ray field of view at the required magnification.The technique has been successfully applied to a Ni-YSZ electrode material: X-ray nano-CT has been conducted at varying length scales and is shown to provide good agreement; comparison of results from X-ray and more conventional FIB tomography is also demonstrated to be favourable.Tomographic reconstructions of SOFC electrodes with volumes spanning two orders of magnitude are presented. © 2010 Elsevier Ltd.

Gelb J.,Xradia Inc.
Advanced Materials and Processes | Year: 2012

In contrast to conventional x-ray CT setups, the long working distance and switchable magnification afforded by x-ray microscopy enables investigation of materials in their true natural state without sectioning for high-resolution 4-D studies. XRM accommodates in-situ experimental apparatuses including commercial batteries and compression and tensile loading stages. The technique can be extended to tens of nanometers length scale using x-ray optics for nondestructive 4-D investigation of today's advanced materials.

A multi energy, such as dual-energy (DE), x-ray imaging system data acquisition and image reconstruction system and method enables optimizing the image contrast of a sample. Using the DE x-ray imaging system and its associated user interface applications, an operator performs a low energy (LE) and high energy (HE) x-ray scan of the same volume of interest of the sample. The system creates a low-energy reconstructed tomographic volume data set from the set of low-energy projections and a high-energy tomographic volume data set from the set of high-energy projections. This enables the operator to control the image contrast of selected slices, and apply the information associated with optimizing the contrast of the selected slice to all slices in the low-energy and high-energy tomographic data sets. This creates a combined volume data set from the LE and HE volume data sets with optimized image contrast throughout.

Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 96.20K | Year: 2007

We propose to develop an x-ray imaging system to directly visualize and measure the 3D morphology of the nano-porous electrochemical interaction area of a solid oxide fuel cell. Extensive research efforts are required to increase the efficiency and reliability of Solid Oxide Fuel Cells. The proposed system introduces many important new non-destructive in-situ imaging capabilities for measuring structural parameters of an SOFC that directly predict its performance, observing its dynamic structural changes during operation, and studying its aging and contamination mechanism. These direct and relevant information provided by this system will greatly improve the efficiency of SOFC R&D activities, leading to significantly reduced development time and increased reliability. We have demonstrated the basic concept and potential of the proposed system in a preliminary experiment. During the Phase I project, we will demonstrate the ability to prepare a SOFC sample for the imaging operation while maintaining its active area and furthermore, the ability to study the 3D morphology of this sample with sufficient throughput for observing its dynamic changes during normal operation as well as accelerated aging testing.

Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 912.12K | Year: 2008

DESCRIPTION (provided by applicant): We propose to develop the x-ray Wolter capillary mirror with outstanding optical properties that will impact many existing x-ray characterization and analysis tools relevant to biomedical research. In combination with r ecently available high brightness microfocus x-ray sources, it could increase the throughput of many x-ray techniques up to 10 times and reduce initial tool purchase cost and subsequent maintenance cost. For the proposing company, we plan to use it in our x-ray 3D imaging systems with sub-30 nm resolution, including a prototype 3D imaging system developed under a NIH phase II funding, which is optimized for imaging biological samples at 30nm resolution. The combination of this performance improvement and lo wer cost will help to make the tool widely deployed in biological laboratories. 3D x-ray imaging of cells, cell clusters and tissues at 30nm resolution has the potential to open new insights into the organization, evolution and connectivity of biological s ystems and naturally complements the already available toolset for biological researchers. The Wolter capillary mirror will also substantially improve the performance of many other well established, relevant x-ray techniques, including protein crystallogra phy for determination of crystallographic structures of proteins and viruses, and small angle scattering for studying biological macromolecules in native solution both in vitro and in vivo, which are important tools for drug development and the understandi ng of disease. Similar to that for x-ray microscopy, a throughput gain of 10X may be expected for some specific applications in these other x-ray techniques. During the phase II project, we plan to refine our fabrication processes and improve our metrology capability to allow the fabrication of Wolter capillary lenses with a point spread function better than 1 ltm. Project Narrative Successful development of the proposed Wolter mirror optic will make 3-D x-ray microscopy for biological applications more pow erful, affordable, and practical by reducing image acquisition times from several hours to tens of minutes (approximately 10X throughput gain). Exciting capabilities include in-situ 3D imaging of cell and tissue specimens with 30 nm resolution that have un dergone little morphological and functional change from their natural living state. In addition to 3-D x-ray imaging other x-ray techniques, such as x-ray diffraction and small angle scattering, critical to drug discovery and understanding of disease, can expect a similar throughput increase from this development.

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