Speaker
Description
The FCCee physics program relies on an accurate knowledge of the centre-of-mass energy of the collisions. A key input to the centre-of-mass energy is the accurate measurement of the single beam energy which can be obtained from resonant depolarization of the e+ and e- beams as demonstrated at LEP. Resonant depolarization requires however beams with a minimum of transverse polarization. The FCCee baseline scenario to obtain transversely polarized beams relies on non-colliding low intensity bunches. Those bunches are polarized using powerful wigglers during around two hours before injection of the main beam. This scheme complicates the machine cycle an recovery from beam aborts and has an important impact on machine availability for physics data taking, in particular in the event of frequent beam aborts. An alternative scenario relies on the injection of polarized beams into the collider ring. This option requires a polarized source followed by transport of the polarized beam through the transfer line into the booster and by preservation of the polarization during acceleration in the booster until injection into the collider. This presentation will outline the current status of the FCCee studies concerning injection of polarized beams.
