Developments in optically focusing reflectors for small-angle X-ray scattering cameras

The quality of the reflecting surface and the mechanical perfection of the bending mechanism are factors which affect the performance of curved glass reflectors in optically focusing small-angle X-ray scattering cameras. The intensity of the reflected beam can be enhanced by gold-coating the reflector, both because of the higher reflectivity of gold and because larger grazing incidence angles are possible, thus increasing the optical aperture. Coating imperfections and the use of increased incidence angles are factors which increase the parasitic scattering. A new bending mechanism is described in which two 200 mm long reflectors are arranged in series to form a reflector of effective length of nearly 400 mm.