Closed orbit correction of the CERN antiproton collector ring

This paper presents various results obtained from the closed orbit correction system. The acquisition system consists of 60 beam position monitors; the set of correctors comprises 56 quadrupoles. Furthermore the 24 bending magnets may also be considered as horizontal correctors. All closed orbit corrections are achieved by displacing transversely quadrupoles or moving longitudinally dipoles (more practically by shimming the dipoles). The correction software ORBCOR minimizes the mean square deviation of the orbit at pick-up stations. The calculations make use of an Antiproton Collector lattice created by MAD program. The horizontal and vertical closed orbit corrections have been successfully accomplished in June 1987. A last horizontal correction took place in March 1988, after ring realignment to improve machine acceptances. Staring from rms and peak-to-peak values of 3.5 mm and 12.0 mm, they were reduced to 1.3 mm and 5.1 mm