Precise Alignment of Magnetic Quadrupole Axes for PETRA III

For the alignment of the magnetic axes of PETRA III quadrupoles the tolerances are very tight. The accuracy requirements by the machine optics for the magnets in one girder cell are below 50 mum, both laterally and vertically. This leads to a girder concept commonly used in several synchrotron facilities around the world. A new alignment concept using multiple laser trackers is shown in detail and the principle of adjustment is explained. A new concept of rigidly connecting the magnets to the massive girder structure is shown, which is very effective in terms of stability and nevertheless cost efficient. Experiments show the feasibility of these ideas and prove an alignment accuracy below 40 mum. The results of dynamic analysis of this new girder system are shown.