A fast global beam position feedback system for Super-ACO

A fast global feedback system has been installed on Super-ACO in order to improve beam stability. The feedback uses all the 16 BPMs of the machine and 8 correctors in each plane. Two different correction algorithms have been tested, a harmonic based method and a direct inversion of the response matrix using the SVD technique. The fast corrections are computed by 8 DSPs connected by a fast digital data link in order to achieve a correction bandwidth exceeding 100 Hz. Each DSP acquires the data for both planes of 2 BPMs and computes the output correction for 2 correctors. In this paper, we present the current status of the implementation of the system. We give the results on the efficiency of the orbit correction and the improvements on the photon beam stability.