Acceleration of Polarized Electrons in the 2.5 GeV Synchrotron at Bonn

Polarized electrons have been accelerated in a synchrotron for the first time. The experiments clearly state that acceleration of a polarized beam in a synchrotron is possible without loosing polarization at least up to 2 GeV. Strong depolarization is observed only in narrow energy bands due to imperfection and intrinsic resonances. Careful measurements of a certain imperfection resonance allows to do a very precise absolute energy calibration of the synchrotron.