Diffraction enhanced imaging computed tomography (DEI-CT) at the BMIT facility at the Canadian Light Source

A synchrotron source such as available at the Canadian Light Source provides the ability to use a large number of imaging techniques. Computed tomography (CT) can be a extension of many X-ray imaging techniques. The ability to turn two dimensional projections into three dimensional structures is a powerful method of data analysis. CT also allows the user to slice the data in any desired direction without the need to cut up the sample. Diffraction enhanced imaging (analyzer based imaging) uses a crystal to measure refraction of the sample which may give significantly larger contrast than absorption alone. Measurements typically involve make images at multiple positions of the analyzer crystal and then using the images to extract the absorption, refraction components. Multiple-image radiology increases the number of images and adds the ultra-small-angle scatter. This paper will discuss the practical and technical aspects of extending diffraction enhanced imaging (DEI) to three dimensions (DEI-CT). A combination of hardware and software is used to provide a stable x-ray beam for the duration of potentially long measurement times and thus enable measurement of good quality diffraction enhanced imaging computed tomography (DEI-CT) data.