APPLE UNDULATOR FOR PETRA III

摘要

Currently, the storage ring PETRA is being rebuilt to a light source with an ultra low emittance. The undulator radiation will take full advantage of this high performance. Within the energy range of 250-3000eV an APPLE II type undulator will provide light with arbitrary polarization. This APPLE II undulator is under construction at BESSY. Results of the detailed magnet block characterization including block inhomogeneities are presented. The total length of 5m and a minimum gap of only 11mm cause strong 3D forces which require a sophisticated mechanical layout. The mechanical concept and the expected deformations are presented.