A new data collection strategy for performing synchrotron energy-dispersive X-ray diffraction computed tomography has been devised. This method is analogous to angle-dispersive X-ray diffraction whose diffraction signal originates from a line formed by intersection of the incident X-ray beam and the sample. Energy resolution is preserved by using a collimator which defines a small sampling voxe...

In addition to imaging, simultaneous diffraction of x rays within crystals makes possible other applications. One involves the substantial reduction of x-ray absorption along directions that satisfy diffraction conditions with respect to several sets of crystal planes. We have demonstrated such reduction in absorption for various cases of simultaneous diffraction in germanium. Such reduction ca...

The general method to obtain solutions of the Maxwellian equations from scalar representatives is developed and applied to the diffraction of electromagnetic waves. Kirchhoff’s integral is modified to provide explicit expressions for these representatives. The respective integrals are then evaluated using the method of stationary phase in two dimensions. Hitherto unknown formulae for the polari...

Lensless imaging is an approach to microscopy in which a high-resolution image of an object is reconstructed from one or more measured diffraction patterns, providing a solution in situations where the use of imaging optics is not possible. However, current lensless imaging methods are typically limited by the need for a light source with a narrow, stable and accurately known spectrum. We have ...

of the Dissertation Soft X-ray diffraction imaging with and without lenses and Radiation damage studies

A simple pictorial model of electron interference effects based on an extended representation of the autocorrelation function is described and developed. Unlike Abbe's theory of transmission imaging, the model incorporates fully the effect of the loss of phase that occurs in the detector plane. The aperture transfer function and information limit (envelope function) are also incorporated with r...

We describe the design and application of a new in-laboratory diffraction-enhanced x-ray imaging (DEXI) instrument that uses a nonsynchrotron, conventional x-ray source to image the internal structure of an object. In the work presented here, a human cadaveric thumb is used as a test-sample to demonstrate the imaging capability of our instrument. A 22 keV monochromatic x-ray beam is prepared us...

Optical imaging has offered unique advantages in material researches, such as spectroscopy and lifetime measurements of deeply embedded materials, which cannot be matched using electron or scanning-probe microscopy. Unfortunately, conventional optical imaging cannot provide the spatial resolutions necessary for many nanoscopic studies. Despite recent rapid progress, super-resolution optical ima...