Hartmann wavefront sensor and adaptive x-ray optics developments for synchrotron applications

We report on the design and performances of a test prototype active X-ray mirror developed for the French national synchrotron radiation facility SOLEIL in collaboration with a French company ISP System. The active mirror uses 11 mechanical actuators: one actuator for the main curvature and 10 actuators along the mirror surface for correction of the residual shape errors. Its radius of curvature can be adjusted from infinity down to 50 m, with residual slope errors in correction less than 0.6 mu rad RMS over a 300 mm useful length. A dedicated X-ray Hartmann wavefront sensor, based on YAG:Ce wavelength conversion to visible light, was developed for feedback control of the mirror. Closed-loop experiments were performed at 10 keV on the Metrology and Tests Beamline at SOLEIL.