Figure 1
Cross-sectional view of a capillary segment with elliptical internal profile. X-rays from a divergent point source located at the left focus of the ellipse converge to the opposite (right) focus after reflecting at a glancing angle from the internal surface. The maximum divergence of the focused beam, θdiv, results from rays collected from opposite sides of the tube. A second smaller divergence, θm, is from the elliptical curvature itself. Focal length F, capillary length Lc and distance to source L, together with maximum divergence, fully specify the capillary design. Parameter r measures the radial distance from the center of the focal spot within the focal plane (dotted line). The scale is highly compressed for the purposes of illustration since L >> F. |