Alternative proposal for FCC-hh extraction septa

Challenging requirements are set for the FCC extraction septa magnets, notably for the magnetic field level, the septum thickness and the leak field. An alternative to the baseline FCC extraction layout is proposed, consisting of a Superconducting Shield (SuShi) stage and a Truncated Cosine $\theta $ (TCT) septa stage with the aim of reducing the required number of septa and installed length. The principal parameters of the septa are described and the feasibility discussed. Areas for further improvement are identified.