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Sandia National Laboratories is developing a laboratory-based x-ray phase contrast imaging (XPCI) computed tomography (CT) system. This system utilizes a Talbot-Lau interferometer based on in-house fabricated gratings and a conventional x-ray system. Initial work has focused on adding CT capabilities to a 28 keV XPCI system. A new set of gratings tuned for an x-ray energy of 100 keV is being developed. This new grating set will facilitate imaging denser components. System configuration details will be presented as well as a discussion of the challenges associated with building an XPCI CT system. Additionally, initial imaging results will be presented.

X-ray phase contrast imaging (XPCi) using the Talbot-Lau grating interferometer attracts increasing attention for its implementation in various fields of applications such as in the (bio-) medical domain, non-destructive testing or security. Since the method is compatible with laboratory X-ray tube sources as well as with large field of view digital X-ray image sensors, it has a large potential to provide XPCi for industrial and medical applications as widespread as conventional X-raying is. Here, we report on our recent results and measurements regarding the grating interferometer technology.

In this paper, the advance in the key devices of grating-based x-ray phase-contrast imaging technique, including a new x-ray tube, an x-ray phase grating, and an x-ray image detector assembly of dual function, has been introduced at Shenzhen University. A Talbot-effect-based imaging system consisted of these devices has been built up, in which there is only a phase grating without any absorption grating. Some small samples have been imaged on the system and their differential phase contrast images have been obtained. The simplification of the system can be favorable to the application progress of the grating-based x-ray imaging technology in the future.

In the late '90s, the concept of "edge illumination" was developed at ELETTRA in Italy as an alternative method to increase the phase sensitivity of an imaging system. The main idea was to be able to reproduce the fine angular selection of "analyzer" crystals without actually using a crystal, as this would allow employing the method with divergent and polychromatic (i.e. conventional) x-ray sources. It was observed that this could be achieved by illuminating only the edges of the detector pixels, and that the method's sensitivity could be progressively increased by illuminating smaller pixel fractions closer to its physical edge. A few years later the idea was adapted for use with a conventional source by means of two sets of x-ray masks ("coded aperture" masks), which enabled obtaining the same effect for each row (or column) of pixels of an area detector illuminated by a cone beam. This article reviews the method and presents recent examples of application.

X-ray phase contrast imaging and tomography using a Talbot grating interferometer is currently available for user experiments at BL20B2 in SPring-8. The measurement condition for X-ray phase contrast tomography has been optimized to achieve high-sensitivity measurements of biological soft tissues and organs. Some biological samples were measured to demonstrate the high-sensitivity imaging.

In the X-ray and neutron Talbot (-Lau) interferometry, fabrication of phase or amplitude grating with a high-aspect ratio is a key factor to obtain high quality images. To improve the ability of the grating, evaluation of shape and thickness variation and feed-back to the fabrication process are essential. Here, it is shown that X-ray projection microscope with a spatial resolution of sub-micrometer is a powerful tool for the purpose. Three kinds of gratings have been evaluated by using a projection X-ray microscope with X-ray source size of 0.6 micrometer. Uniformity of thickness of the grating has been visualized nondestructively.

We image black lipid membranes based on hard x‐ray Fresnel diffraction, with phase contrast arising from free space propagation of the beam traversing the sample. We show that for the studied membranes a simplified but extendable model can be used to quantitatively monitor the thickness and its changes during the thinning process of BLMs.

We report anultrafast x‐ray phase‐contrast imaging study of a gasless composite reactive (Si‐coated W wire) system undergoing high heating rates (104–2.5×105 K/s). Construction of an imaging system utilizing a high‐speed CMOS camera and the third‐generation synchrotron at the Advanced Photon Source of Argonne National Laboratory allows for imaging of microstructural changes of the reactive system over previously unstudied time frames and length scales. Imaging was performed at speeds up to 36,000 frames per second with 10 μm spatial resolution. Using Computer‐Assisted Electrothermography (CAE), the heating rate of the gasless reactive system W‐Si is controlled and its kinetics is measured. A physical description of the changes undergone by the system during melting and reaction are captured by the high‐speed imaging system and correlated to the recorded CAE data. The initial Si melt, as well as the initial reaction, is seen to be non‐uniform along the wire. A secondary reaction, undetected by CAE data, is...

We briefly review currently practiced methods of X‐ray phase contrast imaging and consider some of their relative features, especially in regard to applicability to clinical medical studies. Various related technological issues and promising future areas of development are also briefly discussed.

Since Rontgen’s discovery of X rays in 1895 the vast majority of radiographs have been collected and interpreted on the basis of absorption contrast and geometrical (ray) optics. In recent years the possibility of utilizing phase-contrast effects has received considerable attention, much of this activity stemming from the possibility of producing X-ray beams of suitably high coherence at synchrotron sources (1). A description of a phase-contrast imaging (PCI) technique which utilizes a laboratory-based microfocus X-ray source to achieve the required spatial coherence, and does not rely on there being a high degree of chromatic coherence, will be described (2). The method employs a relatively large object-to-image distance to allow wave interference (Fresnel diffraction) to occur and manifest itself as contrast formation in the intensity distribution recorded at the image plane. PCI is particularly relevant to the nondestructive characterization of materials and this will be demonstrated by way of some exa...