We are developing a new hard x‐ray nanoprobe instrument that is one of the centerpieces of the characterization facilities of the Center for Nanoscale Materials being constructed at Argonne National Laboratory. This new probe will cover an energy range of 3–30 keV with 30‐nm spacial resolution. The system is designed to accommodate x‐ray optics with a resolution limit of 10 nm, therefore, it requires staging of x‐ray optics and specimens with a mechanical repeatability of better than 5 nm. Fast feedback for differential vibration control between the zone‐plate x‐ray optics and the sample holder has been implemented in the design using a digital‐signal‐processor‐based real‐time closed‐loop feedback technique. A specially designed, custom‐built laser Doppler displacement meter system provides two‐dimensional differential displacement measurements with subnanometer resolution between the zone‐plate x‐ray optics and the sample holder. The optomechanical design of the instrument positioning stage system with n...