Analysis of normal and skew quadrupole errors at the ESRF

摘要

The paper summarises the methods taken and analysis made so far onthe normal and skew quadrupole errors at the ESRF. With the conventionalresponse matrix approach, normal and skew quadrupole errors areextracted respectively from the diagonal and off-diagonal parts of thematrix. Independently, the thousand-turn BPM diagnostic implemented atthe ESRF is used to measure the optical asymmetry and the betatroncoupling. The excellent accuracy of the turn-by-turn BPMs allows thecoupling to be measured by constructing the phase space and performingthe normal mode decomposition. The consistency of the results from thetwo methods is examined. An attempt is made to trace the origin of theobtained errors