Following the recommendations of the European Strategy Group for High Energy Physics, CERN launched the Future Circular Collider Study (FCC) to investigate the feasibility of largescale circular colliders for future high energy physics research. In the electronpositron collider of the study, FCCee, large synchrotron radiation losses cause the beam to have large local deviations from the design energy. These energy deviations cause orbit osets and create the socalled sawtooth eect, which causes particles to pass the magnets of the accelerator ocentre. This in turn causes perturbing magnetic elds via the feeddown eect. In order to correct the sawtooth eect and therefore the feeddown eect, the dipole magnets in the machine can be adjusted to the local beam energy in a process called dipole tapering. In the course of this thesis, dierent dipole magnet tapering scenarios are compared in terms of their eectiveness, feasibility and cost. Furthermore, this thesis focuses on tuning the horizontal beam emittance using wigglers. A small value of the beam emittance corresponds to a small beam crosssection, resulting in an increased likelihood of particle collisions and thus a higher luminosity. However, a number of perturbations can cause the beam emittance to deviate from its design value. In order to restore the design emittance, wigglers are implemented in the accelerator lattice. Dierent wiggler designs will be presented for both decreasing and increasing the value of the horizontal beam emittance. It will be shown, that an emittance decrease and increase by a factor of 10 % with an acceptable increase in synchrotron radiation is possible. The last section of this thesis focuses on chromaticity correction in FCC ee and its inuence on the beam emittance. Chromaticity correction schemes with varying numbers of sextupole families are implemented into the FCCee lattice. Sextupole strengths are optimized using a downhill simplex algorithm in order to reduce chromaticities up to the fourthorder. Finally, emittance calculations after the application of each correction scheme show, that chromaticity correction schemes can have a signicant inuence on the beam emittance, which should be considered in the design of these correction schemes.
