Challenges and Status of the FCC-ee Lattice Design

Following the recommendations of the European Strategy Group for High Energy Physics, CERN started the Future Circular Collider Study (FCC), a design study for possible future circular collider projects to investigate their feasibility for high energy physics research. One part of this study is FCC-ee, an e⁺/e^{−} collider with a circumference of 100 km. Challenges for the lattice design result from operation at four different beam energies ranging from 45.5 GeV to 175 GeV. Very high beamstrahlung effects at high energies and the beam-beam limit at low energies request emittance parameters that rise with decreasing beam energy. This talk will present the status of the lattice design and the lattice modifications needed to achieve the requested emittance parameters.