Orbit stabilization in SPring-8 storage ring

Stability of electron orbit is one of the most important properties to achieve brilliant photon beams for third generation synchrotron radiation sources. In the design of a SPring-8 storage ring, many ideas for orbit stabilization were thus considered. Consequently, without any correction, electron orbit stability of about 50 /spl mu/m per day is obtained. Since a main part of the orbit movement is slowly varying components in time, we are developing both a periodic correction of electron beam energy and that of global orbit to realize the orbit stability of a few /spl mu/m at source points along the ring. Up to now, we have achieved the stability at each insertion device within several microns per day in an amplitude of the main harmonic of the orbit movement and one correction scheme is now routinely used in user operation.