Design Studies for the Extraction Septa of FAIR´s SIS100 Synchrotron

The system for slow extraction of the SIS100 comprises an electrostatic septum, a Lambertson septum and three final extraction septa. The latter will be treated within this paper. Due to the unusual small septum coil widths and the high magnetic field strengths required, the design of these magnets is challenging. The third magnet, for example, has to integrate a main field of 1.85 T and an auxiliary steering dipole of 0.25 T perpendicular. Additionally, all these magnets have to be removable to allow to bake out the vacuum chambers for the extracted and the circulating beam, respectively.