Fixed Exit Monochromator with Fixed Rotation Axis

A new simple design for a fixed-exit monochromator has been developed. The set-up uses a linear slide to couple the rotation of the crystals to a translation of the second one to compensate for the 2hcosTheta dependence of the beam-offset in a double crystal monochromator. This set-up requires just one motor for the rotation of the monochromator, and three piezo-actuators to tune the second crystal. The monochromator has been tested for Bragg-angles between 7degrees and 70degrees.