A fast scanning sagitally-focusing double crystal monochromator for a high-power wiggler beamline at DORIS III

The design of a dynamical sagital-focusing monochromator for hard X-rays (6-60keV) is described. The monochromator consists of two crystals in a pseudo channel-cut arrangement. The first is a mini-channel water-cooled flat crystal. The second is a diamond-shaped ribbed crystal which is clamped by its reinforced central rib. It is bent by applying a force at its apices, allowing radiation of up to 60 keV to be focused. Integrated into the crystal bender mechanism are two actuators that allow the removal of twist in the crystal as it is bent. The monochromator is routinely used in multiple-anomalous scattering studies of macromolecular systems