Simulations of Polarization Levels and Spin Tune Biases in High Energy Leptons Storage Rings

The use of resonant depolarization has been suggested for precise beam energy measurements in the 100 km long Future Circular Collider e+e-. The principle behind resonant depolarization is that a vertically polarized beam excited through an oscillating horizontal magnetic field gets depolarized when the excitation frequency is in a given relationship with the beam energy. In this paper the possibility of self- polarized leptons at 45 GeV (Z resonance) and 80 GeV (WW in presence of quadrupole vertical misalignment is investigated.