Mirror manipulator with independent adjustability using an external spherical joint

A new type of modular mirror manipulator with independent adjustability was developed for the EPU6 (Elliptically Polarizing Undulator) beamline under construction at the Pohang Accelerator Laboratory. The mirror manipulator was designed so that the angular displacements of roll and pitch rotations do not introduce translational displacements and are independent of each other by positioning the mirror center to the center of a newly devised spherical joint. While the designed angular resolution was 3.937 μrad, the angular resolutions for roll and pitch rotations were measured to be 3.94 μrad and 3.85 μrad, respectively. The independent adjustability of roll and pitch rotations was tested and confirmed to be within an acceptable performance range.