  The Future Circular Collider (FCC) study investigates the feasibility of
circular colliders in the post-LHC era. The sub-study FCC-ee is a 100 km
electron positron collider in the energy range of 90-365 GeV. In order to
achieve a design luminosity in the order of $10^{36}$cm$^{-2}$s$^{-1}$
continuous top-up injection is required. The injector chain therefore includes
a 100 km booster synchrotron in the same tunnel as the collider rings. This
paper presents the lattice design of this booster synchrotron and the first
dynamic aperture studies based on the chromaticity correction sextupole scheme.
