Biomedical subjects
Publications and source records attributed to Andrew G Peele.
We apply the method of phase-space tomography to reconstruct x-ray beams focused using a compound refractive lens. We show that it is possible to decouple the effect of aberrations in the optical system from the field and hence measure both them and the original field. We recover the complex coherence function and find that it is consistent with expectations.
We discuss the role of coherence in x-ray imaging and consider how phase-space tomography can be used to extract information about partial coherence. We describe the application of phase-space tomography to x-ray imaging and recover the spatial coherence properties of a one-dimensional soft (1.5 keV) x-ray beam from a synchrotron undulator source. We present phase-space information from a Young's experiment and observe negative regions in the quasi-probability distribution. We show that, given knowledge of the coherence of the beam, we can use partially coherent diffraction data to recover fully coherent information, and we present some simple experimental demonstrations of this capability.
We review the current work on x-ray phase vortices. We explain the role of an x-ray vortex in phase recovery and speculate on its possible applications in other fields of x-ray optical research. We present our theoretical understanding of the structure of phase vortices and test these predictions against experiment. We present experimental observations of phase vortices with charge greater than 3 and observe that their propagation appears to be consistent with our theoretical models.
A new method that uses optical microscopy to determine the physical structure of lobster-eye x-ray optics is described. This approach offers the ability to predict x-ray performance without having to take an x-ray measurement. An overlapping series of images of the entrance and exit faces of an optic are obtained and examined by purpose-built software. A 24-parameter description of each channel is obtained from which a quantitative analysis of all the major optic defects, except surface roughness, is performed. Results for a planar lobster-eye optic are used to illustrate this technique and discuss its abilities as well as directions for future enhancements.