Nikitin, S.A. JACoW Publishing Geneva, Switzerland 978-3-95450-216-5 10.18429/JACoW-eeFACT2018-WEXAA02 English 182-189 WEXAA02 polarization resonance wiggler booster electron Contribution to a conference proceedings 2019 2019-04 https://doi.org/10.18429/JACoW-eeFACT2018-WEXAA02 http://jacow.org/eefact2018/papers/wexaa02.pdf We study a possibility of obtaining transversely polarized electron-positron beams at the CEPC collider. At the beam energy of 45 GeV, this requires the use of the special wigglers to speed up the radiative self-polarization process. A numerical estimation of the depolarizing effect of the collider field errors is made, taking into account the modulation of the spin precession frequency by synchrotron oscillations. In addition, we consider an alternative possibility of obtaining polarization by accelerating the polarized particles in the booster and then injecting them into the main ring. This option saves time spent on the polarization process, and is also crucial for obtaining longitudinal polarization.