A beam expander facility for studying x-ray optics

The detailed study of the performance of full scale x‐ray optics often requires the illumination of large areas. This paper describes a beam expander facility at the Daresbury Synchrotron Radiation Facility. It combines monochromatization and beam expansion in one dimension. The beam expansion is obtained from an extremely asymmetric reflection in a large single crystal of Si. An expansion of a factor of 50 was obtained in one dimension. The expanded beam of ∼85 mm is limited only by the crystal size. The facility is installed in a 12‐m‐long hutch. A specific application, in which a high throughput x‐ray telescope will be studied, is described in detail.