Developing a Brushless Permanent Magnet Synchronous Drive for a X-Ray Microscope Condenser in Ultra-High Vacuum

To develop new high density magnetic storage media and magneto-electric devices the knowledge of structure of used materials is most important. Therefore an investigation of this structure proceeds with a magnetic transmission X-ray microscope. For this purpose a X-ray beam has to be conical diverted with a special mirror assembly called condenser inside ultra-high vacuum surrounded by a steel tube. The existing system, at the synchrotron Bessy II in Berlin, uses a magnetic clutch and a tooth belt to make the condenser rotate. This causes vibrations. The paper presents an innovative approach, developed for the Max-Planck-Institute for metals research, Stuttgart, to run the mirrors without the mentioned problem. The new system benefits tremendously from a direct synchronous drive with permanent magnetic excitation where the active rotor part is adapted to the mirror construction and the stator is mounted on the outer side of the vacuum tube