High Accuracy Rotation Stage for X-Ray Diffractometry

A critical component to the overall performance of the diffractometer is the rotary positioning system. Accurate positioning of the source and detector with respect to the specimen and minimization of the "sphere error" is essential for characterization of multilayers and new X-ray powder standard reference materials. OPTRA will develop a new rotary stage that directly monitors the rotation of the platen, thereby eliminating any inaccuracies in the rotary drive train. The metrology approach is to utilize a novel sensor design to provide accurate and well resolved rotational measurements of a relatively coarse scale, located on the periphery of the rotating table. The approach is robust, accurate, relatively simple, inexpensive, and has substantial commercial potential.