Purdue Research Foundation

Nicholas Roman Pogranichniy

Garth Jason Simpson

Ryan Douglas Muir

Justin Allen Newman

Nicole Mulready Scarborough

The present disclosure provides a system and method for efficiently mining multi-threshold measurements acquired using photon counting pixel-array detectors for spectral imaging and diffraction analyses. Images of X-ray intensity as a function of X-ray energy were recorded on a 6 megapixel X-ray photon counting array detector through linear fitting of the measured counts recorded as a function of counting threshold. An analytical model is disclosed for describing the probability density of detected voltage, utilizing fractional photon counting to account for edge/corner effects from voltage plumes that spread across multiple pixels. Three-parameter fits to the model were independently performed for each pixel in the array for X-ray scattering images acquired for 13.5 keV and 15.0 keV X-ray energies. From the established pixel responses, multi-threshold composite images produced from the sum of 13.5 keV and 15.0 keV data can be analytically separated to recover the monochromatic images through simple linear fitting.

Linear fitting of multi-threshold counting data

Methods for determining the 3-D structures of proteins. Such a method includes incorporating a compound into a protein crystal such that the compound enhances the activity of the protein crystal to second harmonic generation, illuminating the protein crystal with a sufficiently intense light to cause second harmonic generation by the protein crystal, and detecting a second harmonic generation response produced by the protein crystal that is suitable for protein structure determination by diffraction analysis.

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West Lafayette, IN, United States of America

Nicholas Roman Pogranichniy