Interpretation of capillary generated spatial and angular distributions of x rays: theoretical modeling and experimental verification using the European Synchrotron Radiation Facility Optical beam line

摘要

Using a detailed ray-tracing code for capillary optics, interpretation is given for parallel bore hole and tapered capillary generated far-field images, These images can be used to indicate the presence of various types of surface imperfections(i.e., surface roughness or waviness) or shape distortions of the optical device. The capillary output patterns were recorded at the optical beam line of the European Synchrotron Radiation Facility by using a monochromatic, highly parallel incidentsynchrotron beam. Capillaries of various dimensions were studied, with inlet diameters in the range of 30-70 μm, outlet diameters of 22-42 μm, and capillary length values ranging from 10 to 23 cm. The far-field images were taken at a distance of 10-11cm from the capillary exit using a high resolution charge coupled device camera. By comparisons of simulated and experimental capillary output patterns, the effects of surface roughness/waviness, as well as axial distortions are studied with respect tothe angular distribution of the generated capillary beam.