White Light Focusing Mirror

Eric Johnson, Aaron Lyndaker, Alex Deyhim, Michael Sullivan, Mark Chance, Don Abel, John Toomey, Steven Hulbert
2007 AIP Conference Proceedings  
The NSLS X28C white-light beamline is being outfitted with a focusing mirror in order to increase, as well as control, the x-ray intensity at the sample position. The new mirror is a 50 mm x 100 mm x 1100 mm single crystal silicon cylindrical 43.1mm radius substrate bendable to a toroid from infinite to 1200 m radius. The unique feature of this mirror system is the dual use of Indalloy 51 as both a mechanism for heat transfer and a buoyant support to negate the effects of gravity. The benefit
more » ... the liquid metal support is the ability to correct for minor slope errors that take the form of a parabola. A bobber mechanism is employed to displace the fluid under the mirror +/-1.5 mm. This allows RMS slope error correction on the order of 2 urad. The unique mounting of the mirror ensures the contributions to slope error from errant mechanical stresses due to machining tolerances are virtually non-existent. After correction, the surface figure error (measured minus ideal) is <= 0.5 urad rms.
doi:10.1063/1.2436152 fatcat:y7kxjin7pngwleagix5fcbyinm