Comparison of Superconducting Septa Topologies and Parameter Space Exploration

The unprecedented energy scale of the FCC poses challenging requirements for its magnetic elements including the septum magnets for injection and extraction. With an ambitious target field of 4 T and an apparent septum thickness of only 25 mm, different superconducting septa topologies have been investigated to explore their limitations. This article will cover the currently feasible topologies, amongst which the truncated cosine-theta, the double truncated cosine-theta, the superconducting shield (SuShi) and the so called stealth dipole. A performance figure of merit will be proposed, taking into account the maximum achievable magnetic field, the septum thickness and the leak field magnitude.