Spin Polarization Simulations for the Future Circular Collider e⁺e⁻ using BMAD

Measurements of particle properties with unprecedented accuracy in the Future Circular Collider e⁺e⁻ (FCC-ee) are reliant on the high precision center-of-mass energy calibration, which could be realized via resonant depolarization measurements. The obtainable equilibrium spin polarization levels under the influence of lattice imperfections should be estimated via spin polarization simulations. An early-stage exploration of spin simulations in the FCC-ee has been conducted using Bmad. An effective model has been used to generate residual errors for the simulation of realistic orbits after lattice corrections. The influences of depolarization effects near the first-order spin-orbit resonances are displayed in linear polarization simulations, highlighting the demand for good closed orbit control. Furthermore, the first attempts at performing nonlinear spin tracking simulations in the FCC-ee reveals the full impact of lattice perturbations. Proceedings of the 65th ICFA Advanced Beam Dynamics Workshop on High Luminosity Circular e+e- Colliders, eeFACT2022, Frascati, Italy