Scanning X-ray interferometry over a millimeter baseline

Abstract
A new translation device has been developed at the Istituto di Metrologia ''G. Colonnetti'' (IMGC) to improve the measurement of the (220) lattice spacing in silicon by X-ray/optical interferometry, It is capable of millimeter linear displacement and servo controls ensure picometer and nanoradian resolutions in crystal position and attitude, It has been successfully used to drive a scanning X-ray interferometer over a 2 mm displacement, thus extending by more than one order of magnitude the maximum crystal movement obtained before