Figure 14
(a) Simple concave defocusing for a 5 µm beam size at focus (400 mm from center of mirror), (b) five-segment for 4 µm beam size at focus, (c) seven-segment for 4 µm beam size at focus. Beam profiles calculated by SHADOW (Sánchez del Río et al., 2011). Black (bottom) curves represent perfect mirrors with no polishing errors. Slight non-uniformities are due to restriction of illumination over super-polished length, leaving the far edges of the re-entrant modifications dark. Subsequent curves in each plot are based on measurements of the mirror's real surface (including polishing errors) using Diamond-NOM and X-ray speckle tracking on B16. For the B16 data, ray traces were performed with the detector at 399 mm and 400 mm from the center of the mirror. |