INSTRUMENT FOR MOVING AND POSITIONING OF OPTICAL ELEMENTS WITH NANOMETRIC MECHANICAL STABILITY AND RESOLUTION IN SYNCHROTON LIGHT SOURCE BEAMLINES

摘要

An instrument for moving and positioning of an optical element in beamlines comprises a mounting structure to which one (or more) optical element(s) is mounted, as well as a reference structure, in relation to which the mounting structure is moved by means of a moving means of low (or close to zero) mechanical stiffness and in relation to which the position of the mounting structure is metered by means of a high-resolution interferometer. The invention proposes that the instrument also comprises a balance mass for receiving the reaction force from the moving means of the mounting structure, and both the mounting structure and the balance mass are attached to the reference structure by spring means, with specific stiffness properties, allowing the positioning control of the mounting structure to be done by a control system with main feedback loop with high bandwidth (100 Hz). In order to allow for a broader range of movement between the mounting structure and the reference structure, by means of a cascaded movement, the instrument may further comprise an intermediate structure attached to the reference structure, also preferably by spring means with specific stiffness properties, the complementary structure receiving the mounting structure and the balance mass in place of the reference structure. Such an instrument may be embodied in a new-generation synchrotron light source beamline mounted double-crystal monochromator, being sufficient for this that the spring means to be conveniently chosen, the reference structure to have a main rotation in relation to the incident beam, and in addition to the crystal mounted to the mounting structure, a complementary crystal to be mounted to the complementary mounting structure rigidly attached to the reference structure.