The Circular Electron Positron Collider is designed to provide un-precedented high luminosity at center-of-mass energies of 91 GeV (Z-factory), 160 GeV (W-factory) and 240 GeV (Higgs-factory). Longitudinally polarized colliding beams could provide an extra probe into the precision tests of the standard model as well as the search for new physics. The speaker will present some preliminary studies into the implementation of longitudinally polarized e+/e- colliding beams in CEPC, at the Z-pole and energies beyond.

Zhe Duan obtained a bachelor degree in Department of Engineering Physics, Tsinghua University in 2009, and a Ph.D from University of Chinese Academy of Sciences in 2015.Under the supervision of Prof. Qing Qin, his thesis work was about accelerator physics issues of polarized beams in high energy circular colliders. He was a visiting scholar in Brookhaven National Laboratory in 2012 and 2014, collaborated with Dr. Mei Bai on polarized proton colliding beams in RHIC. After graduation he became a junior staff scientist in the Accelerator Physics Group, Accelerator Division, Institute of High Energy Physics, CAS, and a senior staff scientist since 2018. He is now working on the accelerator design and beam dynamics studies of the High Energy Photon Source under construction in the Huairou Science City, and also on the polarized beam related studies in CEPC.