Stepping motors
Many potentially beam intercepting instruments are driven by stepping motors. They range from lightweight Beryllium mirrors to heavy collimator blocks. These elements have to be positioned to within a few millimeters of the circulating beams with a precision of better than 10 micrometers. The elements are positioned with a screw and nut drive assembly coupled to one end of the stepping motor shaft. The position of the elements are monitored, for beam and equipment safety, in a completely independent way from the drive electronics of the stepping motor by resolvers. A resolver can be coupled to the opposite end of the stepping motor shaft by a wormscrew/wheel assembly which gives one turn of the resolver shaft for the full stroke of the desired displacement.
An example of a detector (BBS) equipped with stepping motors.